Engine choice input wanted.

[Blue Viking]

Hi all.

I am inching towards ordering a complete kit later this year or next year. Some background. I live in Norway, where it just recently became possible to build and title a homebuilt car. One of the limitations is a max horsepower of 20kw (almost 29 HP) per 100 kg (220 lbs) finished car, so about 290 hp for a 2200 Lb car. That is curb weight including all fluids, spare tire and tool kit. So, the heavier engine i have, the more horsepower i can have.
I would like to build a roadster with the IRS, large brakes and coil overs. I am shooting for a well balanced, well handling car, a corner carver if you will. So, I was originally planning for a small block with fuel injection. But then I started reading a little bit about those BB builds, and how happy a lot of those owners are with the engine choice.
So here's my dilemma. I have a Q-code 69 CJ428 Mach1 Mustang that'll have to go to finance my roadster. I have two engines for this car. The original CJ engine, which is complete,but in pieces needing an extensive rebuild, and another freshly rebuilt 428 sitting in the car that is a CJ engine in all respects but the block, which I think might be a SR block?? It has som ribbing down the sides externally. I was planning on selling the Mustang with both engines, but now I'm starting to wonder if I should keep the running 428 and use it in my build, and instead sell the Mustang with the original engine only.

So I am wondering how balanced and agile a BB car will be compared a small block equipped car. It is my understanding that the Roadster is biased a little bit towards the rear weight wise, so maybe it will balance out better with a BB?
I also don't know how much an all steel 428 equipped car will weigh, anybody knows?

Sorry for the long post. English is not my first language, so I tend to get a bit long winded....

[davekp]

Not sure I understand the horsepower to weight requirement between metric and US. Also, how do they determine the HP? Engine or rear wheel HP? You can always de-tune an engine to reduce the HP.

[Boydster]

Am I reading this right? You are allowed 29hp for every 2200 lbs of completed vehicle weight? Thats about how much a Factory 5 Roadster weighs... 2200 lbs. A big block 428CJ will have over 400 hp... your car needs to weigh 30,000 lbs. To be legal, you'd have to use a 1970 Citroen 2CV engine.

[Blue Viking]

Haha, that came out totally wrong, i'll edit it... The correct ratio is 29 hp per 100 kg, which means about 290 hp for a 2200 lbs / 1000 kg car. The horsepower is engine only, no ps/ac or such, just alternator unloaded. The CJ is rated to about 335 hp from the factory, but i dont know if they will accept that, i might have to dyno it, in which case it'll have to be detuned. I could get the curb weight up by putting a big *** spare in there and also a heavy tool kit, but not sure if the authorities would approve..Also it is possible to replace the cast iron heads and intake at a later point, so there are options.
2200 lbs, would that be a small block car? 'Cause then a BB car would probably be about 200 lbs more??

[WIS89]

Hello, and welcome to the club! First off, your English is excellent! I know some native speakers who absolutely butcher the language, so no apologies needed!

I think I understand your HP limitations. That's a curious way of managing high HP cars. I think you can put a big block in there and make it work. As mentioned, you may have to de-tune it some, but I do think it can be done. Plus, it would be great to use that engine in the Roadster.

As far as how the handling will be, I think you will be more than satisfied. These cars handle beautifully, and the modest weight difference won't impact you too much. As some have already mentioned, you can help that by adding weight in other areas to help manage that as well. Moving the battery around is one easy way. You can be creative with helping to get the car balanced, or at least better balanced.

Good luck as you wrap up your planning, and please keep us updated.

Regards,

Steve

[Olli]

Who measure the engines HP ? You or the Norway authorities? 290 HP would be a really weak BB. 290HP could be a very nice 302.

Olli

[wareaglescott]

Is this a one time horsepower versus weight check for initial registration or something they check annually or repetitively?
I would be real inclined to do a combination of detuning the motor and adding some significant ballast in the form of steel plates all over the place if it is a one time check and then after you get past that remove the weight and tune it.

[CraigS]

I see a problem w/ your two engines. The one in parts is the original engine. Whether you put it together or not, any buyer would definitely want to have it with the Mustang. I think it could make a significant difference in your selling price. So, for me, you really don't have an engine for your FFR. So now you can move on to my favorite, a 351. I don't know how often your car may need to be inspected for this HP. Is it just once when it first goes on the road, or does it happen periodically? Reason I ask is a nearly bone stock 351 would give you the 290HP, and it would be very easy to upgrade it later if that is possible. I wouldn't worry about the engine weight. We all know that a BB is heavier, we can all take it to a scale. But it would take a very experienced race driver to be able to feel what a 200# difference does to the car's handling.

[Blue Viking]

I have reached out to the authorities with regard to who measures the hp, but no answer yet. I agree that it would be a weak BB, but the idea of a torque monster in that little car is intriguing + some of the originals actually came with 428's. Of course there are other considerations such as what price I will get for the Mustang with only a non running engine with it, fewer transmission options??, and availability of parts...But my first concern is handling. If a BB car ends up being a nose pushing, understeering dog, at least compared to a SB car, I think I'll pass. I want it to feel nimble and agile.

[GoDadGo]

Having An FE Makes A Period Correct Factory Five!
I bet detuning and adding ballast will likely get the job done.
You can go with a very mild camshaft and install it retarded 2-4 degrees.
The 4" frame tubes should supply the perfect hiding place for adding the ballast you need.
Filling them with oil would gain you roughly 70 pounds that could be easily filled and easily drained.
Pass the inspection, change the camshaft and dump the dead weight and you'll be tearing up all of Europe.

Good Luck From The Dark-Dart Side & Please Keep Us Posted!

[Blue Viking]

Thanks guys, a lot of useful input here. There is a process wherein one applies for a build permit. You have to specify drivetrain then. If it is approved, the process involves an inspection of the car after the frame is finished, and when the car is finished. There is also an inspection two years after completion. I don't think it's a good idea to try and fool the inspectors, they probably know what to look for, and if I'm busted, the whole project is jeopardized. Besides, I'm not fond of cheating, it's just not something I'm comfortable with. It seems the consensus is that a BB won't hurt handling in a big way. I do think it would be a killer engine to have in the car. I mean, the sound even from the restrictive exhaust in the Mustang is awesome. But I hear you CraigS, it's probably a lot easier to go with a 351. I guess I'll just have to put my mustang out there and see what response I get. If I get a decent price for it without the running engine, I still have the option..
Maybe Factory Five will do some killer deals in their anniversary year? By then I have to be ready to seize the opportunity.
After gratiously being given a ride by Alan Marshall in Cape Coral last November, I feel there is no way around it, I have to do this...

[rich grsc]

I just think it's terrible how many guys here are suggesting to build an illegal vehicle, shameful:mad: Your original engine, even disassembled is very valuable to a true car collector. Sell the package and get a stock 351, even 290HP is a blast in a 2400#, which after some heat and sound insulation is about where you'll be.

[Blue Viking]

Hi Rich. I wasn't really offended by the suggestions, I do what I feel is right personally. I would love to put an unlimited amount of horsepower in the car, but historically, anything pertaining to modifying and importing cars has been extremely difficult, so the fact that it now is possible to build a kit car at all is a huge deal. In light of this, I'll take 290 HP all day long, I think it is more than enough for me.
I will never sell the Mustang without the original engine, that would be a crime. I would only keep the quasi CJ engine, and even there, I could probably sell off some of the CJ specific parts.

[GoDadGo]

You could consider building a mild cammed 428 and choking it down simply by running an Edelbrock AVS 500 CFM carb and holding your initial distributor advance to 7-8 degrees.
When you want to get a little more power, stick on an Edelbrock AVS 800 CFM carb and let her rip and roar or simply stuff in a 302 crate motor and call it a day.
Sorry that you have little or no wiggle room regarding your Government's Red Tape!
We've got places (States) like that over here in the U.S.A. that are pretty bad too.
I'm thankful to not live in one of them.

Good Luck From The Dark-Dart Side!

[RR20AC]

Oystein, Why not get a 289 kit an add a 289. Would be a corner carver like you wanted and have all the attributes of an original Cobra and fit with regulations too.

[Blue Viking]

You know, that might be a good solution if I end up using the 428. A carb swap is no more than couple of beers time,easy peasy.
Btw, I now what you mean about some states being worse than others. I once brought a 77 SE TA from SC to CA. They made me put catalytic converters on that thing...

[GoDadGo]

Oystein, Why not get a 289 kit an add a 289. Would be a corner carver like you wanted and have all the attributes of an original Cobra and fit with regulations too.

Excellent Idea!

It was the 289's that won all the races even though the 427's got all the attention.

[GoDadGo]

You know, that might be a good solution if I end up using the 428. A carb swap is no more than couple of beers time,easy peasy.

The 500 and 800 are both square-bores and seem to stumble less than the 650 CFM series that have 250 CFM butterflies up front with 400 CFM butterflies out back.

https://www.edelbrock.com/shop/carburetors.html

For the record, I'm in the minority regarding the Edelbrock AVS Carbs and I'm also in the minority regarding my driveline choice as well.

https://youtu.be/wOID7yvBRPU

Good Luck From The Dark-Dart Side!

[feadam]

Go with the big block. If your thinking about it and you dont do it you will always open the hood and wish it was a big block. Im building my third cobra(in build thread under feadam) this one with another big block. You can always play with suspension for handling and how many of these cars get pushed to limit of handling anyway. With the engine so far back most drivers would never differentiate if car was big or small block. My second car was small block, but I always missed that torque of the first car which was a 428. This one I'm building is a 482 and cant wait for that acceleration.

[Blue Viking]

RR20AC, I don't think I'm going for the original look anyway. With a small block, I kinda envisioned an eight stack type of fuel injection. Mostly because I think it looks cool. I'm not concerned with regulations either, will not be racing it.
With an original CJ mustang, I feel obligated to keeping it original, and I've come to the realization that this is not my game. I want to improve and modify stuff. With a FFR Roadster i have a feeling it'll never be quite finished, which suits me well.

[Blue Viking]

Feadam, I'll make sure to look at your build thread. I'm thinking..Say I'm limited to 290 HP no matter the engine. Would a 290 HP big block engine allow lower gear ratios and better performance than a 290 HP small block?

[feadam]

With the long stroke of the 428 your going to have a lot of torgue. Acceleration wont be a problem. You could probably go with a 3.27 gear still have great acceleration and good cruising RPM.

[Blue Viking]

Hmm. The Mustang is about 1000 lbs heavier, it has a 3.50 rear end, and it goes pretty good... I think you're on to something here. What transmission are you running?

[feadam]

Top loader 4 speed, when you look at my build it has the parts and pictures of most drive train parts.

[cnutting]

Oystein, Why not get a 289 kit an add a 289. Would be a corner carver like you wanted and have all the attributes of an original Cobra and fit with regulations too.

What I would have suggested, but maybe I'm a bit biased... :D

[rich grsc]

A 290hp small block will out perform a 290hp big block on road. Why choke a 428 down to nothing when you could have a nice free breathing 302 or even a 351. The thought of castrating a 428 makes no sense. Plus the lighter car will handle better.

[CraigS]

A 290hp small block will out perform a 290hp big block on road. Why choke a 428 down to nothing when you could have a nice free breathing 302 or even a 351. The thought of castrating a 428 makes no sense. Plus the lighter car will handle better. I agree. Plus I have to assume the inspectors have some knowledge. If I were them, I'd look at that tiny carb on a 428 and immediately figure you are planning to swap the carb as soon as they pass you. I like your stack injection idea. As a point of reference a stock efi Fox 302 was advertised back then as 225 HP. So a bone stock 302 + stacks might be exactly what you need. Maybe add one of the mild Ford letter cams.

[emac]

When I built my FFR back in 2012, there was a member who built a 289 slabside car. He did an undercar exhaust and all the other details. I think this look works great with lower HP. I love the slabside look. This may have been the thread:

https://thefactoryfiveforum.com/showthread.php?7777-First-Factory-Five-Slabside-Finished

[GWL]

I agree with the Ford SB 302. Add shorty headers and you can enlarge both the footboxes for comfortable cruising.

GT40p heads with a Trick Flow mild cam and valve springs will get you in the range of 290HP. A strong dependable engine.

George

[Blue Viking]

It's not an easy decision to make for sure. It seems to me a BB car will handle pretty well, which is what I was curious about. The next step is to determine how the authorities determine HP, and see if there is any wiggle room. I have also started the process of selling my Mustang. I'll have to see if I can get a decent price for it without the running engine. If not, I will sell it with both engines and take it from there. Regardless, I will be looking into the crate engine suggestions, those are very interesting.

[Bob Cowan]

Trying to choke down a 428 to make only 290 hp will make it very inefficient. Even if you destroke it to a 390 and limit it to 5500 rpm's. An efficient engine makes about 1hp per cube. It will look good, but it won't run well at all.


Sell the CJ, they are pretty valuable. Install a nice 302 fuel injected small block. It will be efficient, fun to drive, and last forever.

[Blue Viking]

Trying to choke down a 428 to make only 290 hp will make it very inefficient. Even if you destroke it to a 390 and limit it to 5500 rpm's. An efficient engine makes about 1hp per cube. It will look good, but it won't run well at all.


Sell the CJ, they are pretty valuable. Install a nice 302 fuel injected small block. It will be efficient, fun to drive, and last forever.

All good points for sure. Sounds like the easier way to go as well. Small block is still plan A, but I want to explore the possibility of using the 428 since I have it here already.

[NAZ]

Lucky I live in the free State of Arizona where the gov't is not overly restrictive but if I was faced with a specific HP per weight limit I'd take a much different approach and use a smaller turbo or supercharged engine that I could easily regulate the HP. A low compression ratio that when limited to low boost would provide something just below the max HP for the vehicle's weight but a simple pulley change (or better yet, a boost controller for a turbo) and I would have a screamer. It just depends on the rules around how HP is measured. Not much different than racing -- rules are there to limit you and your job is to stay within the rules while increasing performance without the tech inspector calling you out for a violation.

I understand your desire to run a big block and I read where others have chimed in about the extra weight not being a performance issue. But the fact is, adding weight does affect performance. Until you suspend the laws of physics and that little issue of inertia you will be affecting performance. In your case, not linear acceleration as you already have a HP/weight limit that will limit straight line acceleration but lateral acceleration (cornering) and breaking will be affected by adding more weight. Yes you can mitigate the effects somewhat but it is easier to tune a light car to weave through the cones than a heavy car. So working within the rules you've been given I suggest you consider the pros and cons of how to achieve your HP/weight limit and maximize your handling performance. Adding weight so that you can run more HP will not give you added performance in any measurable category. Acceleration is governed by HP/weight if all other variables are constant. A lighter car with less HP can accelerate the same as a heavy car with more HP. Try outrunning a motorcycle at a stop light. But can you expect a heavier car with the same tires, weight bias, and brakes to stop in the same distance as a light car? Is overall performance more important than HP or engine selection?

The car you are considering building is NOT A FORD so why box yourself in with only Ford power? And whatever is under that hood is hidden until you open the hood to reveal it. If you are building a performance car use whatever parts that meet the goal of maximum performance within your budget. If you are more interested in building a replica of a Cobra then you have just limited yourself to the only practical choice -- a low performance SBF that is a faux copy of a real performance car that was Shelby's vision. And what if he would have gotten a better partnership from Chrysler -- would we see a cottage industry of imitation Shelby Cobras powered by a 392 Hemi?

Whatever you decide -- have fun with your build. And however you build it or personalize it; no one can say it's wrong.

[Al_C]

I'll offer my opinion, too, for whatever that is worth. Your choice depends on your goals. If you really want the look of a big block, then you've got at least part of the solution (whichever 428 you use). If you want the "corner carver", go with a small block. I agree with others - I believe that a stock small block will run a heck of a lot better than a de-tuned big block. To quote Mike Forte - "one of these with a 289 and a 2-barrel would be a lot of fun". In other words, a 290 hp small block, whether it's a 289, 302 or 351, would be a great solution. So to me, determine the vision and your choice becomes clear.

[Blue Viking]

OK, so i've searched a bit locally in forums, and there are some hints that the HP limit may be exceeded somewhat, so i've reached out to our "DMV" to see what they have to say about it. I bragged about the excellent qualities of the FFR chassis, i just hope i didn't lay it on to thick....If i cant go above 300 hp with the 428, i think i'll probably follow the advice from some here and go with a small block. I've looked at Blueprints offerings, a lot of nice engine/trans-combos there. . The 428 can always sit on display in the garage, its nice to look at:-)

[feadam]

The thing that matters most is that what ever you do it makes you happy, big or small block, these cars are a lot of fun and ill bet you will have one of the only ones in Norway.

[Blue Viking]

The thing that matters most is that what ever you do it makes you happy, big or small block, these cars are a lot of fun and ill bet you will have one of the only ones in Norway.

OH, absolutely, it's my project, and I'll do it the way I want to. But it would be foolish not to take advantage of the vast knowledge of this community. If (when) i get a kit, this won't be the last you've heard from me..
There are a few cobra replicas and maybe even some originals in Norway, but I haven seen any FFR Roadster yet. I go to Florida about twice a year, so I have seen some there. I even got a ride in one. That was particularly valuable for me, as i got to experience how solid the design is. Very tight and no rattles and squeaks. And the sound and the smell sitting at the traffic lights.....just WOW!

[davekp]

Where in Florida?

[Blue Viking]

Where in Florida?

Cape Coral. Love it there!

[MPTech]

What if you just ran a restrictive air filter/carb and restrictive exhuast? You could easily upgrade / downgrade as needed.

[erlihemi]

Hmmm, an interesting conundrum. Aluminum heads on an FE long stroke with small EFI throttle body. RPM limited to 5000. Very long intake runners and tri-wye headers. Torque band tuned around 1500 to 4000rpm. Lighten rotating assembly. Think F250 truck approach. Maybe even sleeve bore down. Very rarely do you really need more than 4500 rpm on a street driver. Throttle response makes an engine feel more powerful than it is. You can customize your fuel curve within limits using integrated ignition timing so why not go with the FE if that's what you want.

[Blue Viking]

You know, this will be my first build, so i have decided to keep things simple. I don't want to do any temporary stuff, after all, the car will be inspected again two years after completion. So I will only use the 428 if they will let me run it as it is. If not, I will go with a small block and a good five- or six-speed manual.

[BadAsp427]

Not sure what BluePrint Engines can do as far as shipping to you, but give Johnny a call at BPE. This is their 302 option for the Factory Five Roadster (https://factoryfiveengines.com/blueprint-engines-factory-five-engines/blueprint-engines-mk4-roadster-engines/ford-302-carbureted-mk4). They may even work with you on options and get you closer to your max HP numbers. Tell him Carl sent you... LOL he will get a good laugh from that... Seriously. Plug and Play Engine/Trans combo...

[Todd Buttrick]

Oystein, Why not get a 289 kit an add a 289. Would be a corner carver like you wanted and have all the attributes of an original Cobra and fit with regulations too.

Nailed it! When you're finished with your build, you're going to want to drive the piss out of it. 289/Roadster with a small block will be driven MUCH more than any BB.

[Blue Viking]

Man, just sitting here thinking about my options and planning is exciting. I appreciate all the input, it is very helpful.

[Blue Viking]

Davekp, are you in Florida?

[davekp]

Davekp, are you in Florida?

Yes, but not close to Cape Coral. I'm in Merritt Island.

[Blue Viking]

Yes, but not close to Cape Coral. I'm in Merritt Island.

Ah, i see. Thats not just around the corner. I have been to Daytona Turkey run, and i usually go to Lakeland for the Carlisle Fall event, but haven't been around your neighbourhood before. We have a house in Cape Coral, but we do drive around a little bit when we're there over some time.

[BluePrintEngines]

Not sure what BluePrint Engines can do as far as shipping to you, but give Johnny a call at BPE. This is their 302 option for the Factory Five Roadster (https://factoryfiveengines.com/blueprint-engines-factory-five-engines/blueprint-engines-mk4-roadster-engines/ford-302-carbureted-mk4). They may even work with you on options and get you closer to your max HP numbers. Tell him Carl sent you... LOL he will get a good laugh from that... Seriously. Plug and Play Engine/Trans combo...

Thanks Carl! I knew I liked you!lol

We can ship an engine or combo about anywhere. Or, we can also ship to a freight forwarder of the buyers choosing within the states.

@erlihemi we do have some very nice 302's and 306's that would help with the horsepower goals you need to hit.

all of our pre-done packages can be found here. (click on the engines tab)
https://factoryfiveengines.com/

i have even made some special exceptions piecing kits together using the engines on... https://blueprintengines.com/collections/ford-crate-engines since we have a few more HP levels on the "normal" BluePrints for customers overseas that need lesser HP than the FFR kits.

anything we can do let me know.

Johnny@BluePrintEngines.com

[Driver_WT]

Ah, i see. Thats not just around the corner. I have been to Daytona Turkey run, and i usually go to Lakeland for the Carlisle Fall event, but haven't been around your neighbourhood before. We have a house in Cape Coral, but we do drive around a little bit when we're there over some time.

Hi Oystein, we have a house in Cape Coral as well. Unfortunately, my Roadster is not here, as our full time house is in Nova Scotia, Canada.

[Blue Viking]

Thanks Carl! I knew I liked you!lol

We can ship an engine or combo about anywhere. Or, we can also ship to a freight forwarder of the buyers choosing within the states.

@erlihemi we do have some very nice 302's and 306's that would help with the horsepower goals you need to hit.

all of our pre-done packages can be found here. (click on the engines tab)
https://factoryfiveengines.com/

i have even made some special exceptions piecing kits together using the engines on... https://blueprintengines.com/collections/ford-crate-engines since we have a few more HP levels on the "normal" BluePrints for customers overseas that need lesser HP than the FFR kits.

anything we can do let me know.

Johnny@BluePrintEngines.com

Hi Johnny.

When i eventually decide on what engine to use, i'll make sure to contact you if i end up not using the 428.

[Blue Viking]

Hi Oystein, we have a house in Cape Coral as well. Unfortunately, my Roadster is not here, as our full time house is in Nova Scotia, Canada.

You should bring it to Florida... Wish i had a car over there, but we rent the house, so we need the garage space for our guests...

[Rootbeer Roadster]

When I built my Roadster I wanted a car that was very quick from 0 to 60, well mannered, agile and fun to drive. The purpose was to take drives on the weekend to look at the scenery and have fun with my wife. I went with a 302 Explorer motor that I converted to carb and used a stock 90 Mustang cam. I added a Canton oil pan and some chrome. It was tuned on a dyno and produced 258HP and 285LBs torque. After completion I have given many prospective builders a ride and all have been impressed with the acceleration and drive-ability. Some have copied my build and others have continued with the high horsepower motors. With the car pointed straight I can smash the throttle in 1st gear, hit 2nd all the while the rear of he car is wiggling slightly. When I reach the top of 2nd I'm going 60 and it all happened very fast. I live in a city environment so 3rd gear is only a blip before I back down. The point I'm trying to make is a mild 302 build can be very fun, fast and easy to live with. Your HP restriction will in no way limit your fun, but may save your life and increase your enjoyment. My car has been on the road for 7 years and I'm happy with my choice.

[Driver_WT]

You should bring it to Florida... Wish i had a car over there, but we rent the house, so we need the garage space for our guests...

Well, it is a three day drive and I would have to buy a truck and a trailer to bring the Roadster to Florida. We just bought a 2006 Mazda MX5 for a Florida convertible. It is a fun little car - handles great and goes pretty good.

[Blue Viking]

[QUOTE=Rootbeer Roadster;357490]When I built my Roadster I wanted a car that was very quick from 0 to 60, well mannered, agile and fun to drive. The purpose was to take drives on the weekend to look at the scenery and have fun with my wife. I went with a 302 Explorer motor that I converted to carb and used a stock 90 Mustang cam. I added a Canton oil pan and some chrome. It was tuned on a dyno and produced 258HP and 285LBs torque. After completion I have given many prospective builders a ride and all have been impressed with the acceleration and drive-ability. Some have copied my build and others have continued with the high horsepower motors. With the car pointed straight I can smash the throttle in 1st gear, hit 2nd all the while the rear of he car is wiggling slightly. When I reach the top of 2nd I'm going 60 and it all happened very fast. I live in a city environment so 3rd gear is only a blip before I back down. The point I'm trying to make is a mild 302 build can be very fun, fast and easy to live with. Your HP restriction will in no way limit your fun, but may save your life and increase your enjoyment. My car has been on the road for 7 years and I'm happy with my choice.[/QUOTE

It all depends what I'm allowed to do. Plan A is similar to what you've done, but since I already have the 428' I owe it to myself to explore my options. Still no answer from Norwegian DMV....I do think 300ish HP is plenty in such a light car. I want to go with the IRS, and will then also have to use the 17"wheels. Combined with coilovers, I think it will be very agile yet well behaved.

[Blue Viking]

Well, it is a three day drive and I would have to buy a truck and a trailer to bring the Roadster to Florida. We just bought a 2006 Mazda MX5 for a Florida convertible. It is a fun little car - handles great and goes pretty good.


The Mazda is an excellent car for sure. I usually rent a Mustang convertible. There's something about driving topless in Florida that brings out a huge grin on my face.

[davekp]

300 hp in the cobra is nearly the same power to weight ratio of a current base Corvette C-7. Plenty fast!

[davekp]

Remember also, your gear ratios (trans and diff), can have a big affect on how the car feels when accelerating. Throttle response can affect it too.

[kpeterson]

300 hp in the cobra is nearly the same power to weight ratio of a current base Corvette C-7. Plenty fast!

C7 performance should produce a smile. I didn't realize that 300HP would get one close to high 11s nudging 120.

[Blue Viking]

Remember also, your gear ratios (trans and diff), can have a big affect on how the car feels when accelerating. Throttle response can affect it too.

Yep, I'm aware of those things. I'm thinking a smooth shifting 5 or 6 speed with a nice overdrive ratio on top, and hopefully some tall gears in the rear for good acceleration, but I may well be wrong. With a small block I was thinking 8 stack injection, mostly because it looks cool, but it's pricey, and I've read about low end stumble and poor drive ability, so maybe a throttle body FI like Fitch would be better. When I decide on engine, I will for sure search the forum and ask more questions..

[Avalanche325]

Big block and corner carver do not go well together. Adding weight and adding horsepower at a set ratio only does one thing. It reduces the handling and braking capabilities of the car.

With a power to weight ratio limit, the best thing that you can do is to keep it lightweight and bring power close to the limit. Small block is the way to go for this.

As you may have noticed, the first thing Americans want to do with rules is find a way around them. It would be easy to knock off 100+ HP for testing. However, what people that haven't lived overseas don't realize is that some places actually enforce their laws, and have severe penalties for breaking them. In New Zealand, get caught street racing three times and your car goes to the crusher.

[Blue Viking]

Big block and corner carver do not go well together. Adding weight and adding horsepower at a set ratio only does one thing. It reduces the handling and braking capabilities of the car.

With a power to weight ratio limit, the best thing that you can do is to keep it lightweight and bring power close to the limit. Small block is the way to go for this.

As you may have noticed, the first thing Americans want to do with rules is find a way around them. It would be easy to knock off 100+ HP for testing. However, what people that haven't lived overseas don't realize is that some places actually enforce their laws, and have severe penalties for breaking them. In New Zealand, get caught street racing three times and your car goes to the crusher.

In general I will agree with you with the big block vs corner carver issue. My reason for asking the question in the first place is that I read in one thread about battery placement in the Roadster that its weight distribution is rear biased. Since I have this 428 available, I started wondering if putting it in the car actually would make it more balanced compared to a lighter engine. It seems though that the general consensus is to go with the small block.

[kpeterson]

As you may have noticed, the first thing Americans want to do with rules is find a way around them.

It is embarrassing how little respect average Americans have for laws, rules, regulations and guidelines. There is no excuse. Not only do we have elected officials creating so many fine ways to make us better people, many of these officials make the sacrifice of violating their dictates so that we can see how seriously they are punished when they find a way around the results of their legislative efforts.

https://www.investors.com/politics/columnists/obama-white-house-staff-back-taxes/

http://www.nbcnews.com/id/10794604/ns/politics/t/lapd-governor-rode-motorcycle-illegally/#.XGXFqLhMEzs



I have no way to verify this but when I worked in California, an employee at one of my customers (a large defense company) laughed at how their Detroit division obtained a Michigan license plate for Arnold to put on a vehicle that could not legally be operated in California.

And poor Ted Kennedy. Leaving the scene of a fatal traffic accident cost him the presidency. He had to settle for being election to the Senate seven time post that 1969 mishap.

[Avalanche325]

In general I will agree with you with the big block vs corner carver issue. My reason for asking the question in the first place is that I read in one thread about battery placement in the Roadster that its weight distribution is rear biased. Since I have this 428 available, I started wondering if putting it in the car actually would make it more balanced compared to a lighter engine. It seems though that the general consensus is to go with the small block.

OK. Let's get to it......

The typical thing that you read in magazines "perfect, 50/50 weight distribution" is utter nonsense. It completely depends on the particular car. These cars are specifically designed to have more weight in the rear. That is why the engine sits so far back. The engine could easily be much further forward. These are front mid-engine cars for a reason. To get the weight in the rear where you need it. Put the battery in the rear also.

If you look at specs on modern race cars, supercars, etc. A majority of them have a rear weight bias.

[Duke]

Not sure I follow all the regulations you have to go through correctly, but my 2 cents for what it's worth:

It sounds like it's a one-time test to be come road legal. If it were me, I would build the engine/combo I want then when it came time for testing I would choke the engine down and get it dynoed exactly where it needs to be/add some lead plates to the trunk as needed. Pulling a lot of timing out and putting a lot less air/fuel through should be able to choke the motor down by 100-150hp or more. Once its right on target with a local dyno tuner, get it tested and pass all the regulations. After that, 'upgrade' it accordingly.

[Blue Viking]

OK. Let's get to it......

The typical thing that you read in magazines "perfect, 50/50 weight distribution" is utter nonsense. It completely depends on the particular car. These cars are specifically designed to have more weight in the rear. That is why the engine sits so far back. The engine could easily be much further forward. These are front mid-engine cars for a reason. To get the weight in the rear where you need it. Put the battery in the rear also.

If you look at specs on modern race cars, supercars, etc. A majority of them have a rear weight bias.


I dont really know what the weight distribution is. Would be really interesting to see some numbers for the different configurations, eg. Big/ small-block, Battery up front/ In trunk.

[Blue Viking]

Not sure I follow all the regulations you have to go through correctly, but my 2 cents for what it's worth:

It sounds like it's a one-time test to be come road legal. If it were me, I would build the engine/combo I want then when it came time for testing I would choke the engine down and get it dynoed exactly where it needs to be/add some lead plates to the trunk as needed. Pulling a lot of timing out and putting a lot less air/fuel through should be able to choke the motor down by 100-150hp or more. Once its right on target with a local dyno tuner, get it tested and pass all the regulations. After that, 'upgrade' it accordingly.

Well, there is a re-inspection of the car two years after completion. I'm not gonna make it too complicated anyway, so i will build it legal the first time around. I don't want to risk any problems with the inspectors.

[davekp]

I gave the results for my car a few days ago.
See "Corner Weights" thread.
Dave

[Blue Viking]

I gave the results for my car a few days ago.
See "Corner Weights" thread.
Dave

Thank you, that's really helpful. That is not with a full tank, so i should probably be able to shoot fro about 300 HP. I got a reply from our DMV, and it seems they are really strict with the hp-limits, so small block it is I suppose..

[CraigS]

302, standard T5 gears and 355 diff will be tons of fun. The 355 will make 2nd and 3rd pull quite strongly while keeping 1st still usable. The .6x 5th gear will make for nice cruising. Yeah, it's a pain to be limited but you will have a great car.