Engine HP

[Pirate]

I'd like to get yalls recommendation on engine HP, transmission and rear end. No track racing for this car, cruising, car shows and maybe a drag race or two when the cops aren't looking. I am still planning my MK4 build. I'd love to drop a 427 in this baby but I don't think that is realistic due to cost and also my wife will be driving this car a lot and I just think that is a lot of HP for this light of a car. What engine HP have yall put in. I am looking at a 302, 347 and 351. Does anyone have the 302? Does it have enough HP so you can you woop anyone off the line in a drag? How does it sound? Same for the 347 and 351.

What tranny and rear ends did yall use also. And last but not least who did you get your engine and drivetrain and rear end from and would you buy from them again.

Thank you,

Chris

[CraigS]

I am very happy w/ my 400 hp 351 w/ 331 rear gears. I wouldn't mind another 50 hp though. I really like the 351 as a basis for your engine. As is, it has a lot of the larger internal bolts and nuts that the 302 gets upgraded to when more hp is added so it's very strong. More cubes gives you any given hp level in a milder state of tune. Mine will drive along at 1300 in 5th gear no problem. A key for both of you, since this level of performance will probably be new, is a good throttle setup w/ a nice long pedal travel. This makes it easier to control.

[turbonut48]

Per CraigS
Suggestion go big but mild. Mine is a stroked 351 with big cam. Cant run it below 2200 on highway, actually at any speed.
It wont be as fussy around town. You ll be able to use a T5 which shifts easier than the 600 I have.
Mild also helps the budget.
Good Luck.

The Nut

[Dan Babb]

a 302 with aluminum heads and a good cam will be faster than most cars on the road today (unless you're going to spend big bucks)

I have a 5.0 with edelbrock heads and a decent cam and it's a blast to drive and sounds very good...but it's not a big block. I would like more power now that I'm doing some auto-cross stuff though.

You really need to think about your budget. The money you are willing to spend is the biggest factor in how much power you can have.

[Mike N]

Somewhere between 350 and 400 RWHP is a good place to be with the roadster. A larger displacement will allow you to build an engine with a nice broad torque curve that will be very drivable. Cost wise a nicely built 351 is going to be cheaper than stroking a 302 to 347. My 331 puts 369 HP to the rear tires, runs 11.70's on street tires, 0-60 in under 4 seconds and is a blast to drive. No problem taking care of just about anything from a stop light or from a roll until you get to triple digits then all bets are off due to the fact that you are driving a brick.

So find a 351, bore .030 over, raise the compression to around 10.0:1, add a good set of heads, AFR185's, Edelbrock Victor Jrs, TFS TW 185's and a cam in the 230 duration @ .050 range and a good high flow FI or dual plane carb intake and you should be good to go. Don't get caught up in going for high HP numbers just keep a broad torque curve in mind and you will be very happy behind the wheel. Area under the HP curve is what makes a very pleasant driver and it will be quicker than you might think and it will work with a lower rear gear for good highway mileage. Yes you can put on bigger heads a single plane intake and more cam for an extra 50HP or more but it won't be as nice to drive. Your choice.

[Bob Cowan]

I'd like to get yalls recommendation on engine HP, transmission and rear end.

Chris

A lot. As much as you can afford. More power is just better. No matter how much power you start with, you can almost guarantee that after a short while, you'll be looking for more. There's no such thing as too much power, only not enough control.

My engine makes about 600 dyno proven hp. It's easy to drive on the street, will cruise all day long at 2,000 rpm, and get 20mpg. Press on the skinny pedal, and it screams like a banshee and takes off like a rocket. It doesn't have a torque curve, it has a flat torque table.

Like Mike said, how much power you make isn't nearly as important as how and where it makes that power. You can get 600 hp out of a 302 - but it will be expensive and the car probably won't be a lot of fun to drive. Here's some tips on how to make good and big power:

- There's no replacement for displacement. You can't beat cubes. Go with a 408 or 427 small block. The price difference over a 351 is so small it's not worth talking about. Do it once and be done.

- Head selection: "smaller" ports and valves will make better low and mid range torque. "Smaller" being a relative term. I use standard 2.02/1.60 valves.

- Cam selection: Very important. Don't just go to the bottom of the list, and order the biggest cam you can find. With a stroker, go 1-2 steps below that. For a 351, go 3-4 steps below that.

- Induction: this is the real important part. IMO, you can't get big power and good power at the same time from a carb. It's just not precise enough to make it work. Lots of people will argue with me on this, but most of them have never gotten a performance EFI to work correctly. It is more expensive and more complicated. But that's the whole point. It's a computer controlled system that adjusts itself according to hundreds of variables every second all at once.
--- Many times I have left my house at 0600, the altitude is 6,200' ASL and the temps are in the 50's. By the end of the day, I'v gone as high as 10,000' ASL and as low as 4,500' ASL, and the temps have ranged from 40-90*F. Cruising down I-25 at 85mph, and climbing a mountain pass at 20mph. All day long the engine has run perfectly. Never bogs down or stinks because it's too rich, and never caughs or knocks because it's too lean.
--- I will never go back to a carb.

- For the trans, I would use nothing less than a TKO or T56 Magnum. They are a little more expensive, and they're heavier. But they're indestructible. Build it for strength, and then never worry about it again.
--- For a street car, I think the 6 speed is better. On a 5 speed, there's a 1,000rpm drop between 4th and 5th. The 6 speed adds another gear between those two. There's a lot of situations where that middle gear would be nice.

- The rear should be IRS. I'v built and driven both straight and IRS, and there's no comparison. The IRS rides and handles so much better that it's well worth the extra expenditure in time and money. I used to own a '08 Mustang with a solid axle. The Cobra rode and handled better than the Mustang did.
--- Besides, the only way a T56 will fit is with the IRS. It's too long to use a solid axle.
--- Use a cast iron case, 3.55 gears, and stock Mustang Trac-Loc LSD. IMO, best bang for the buck.

But, that's just my opinion. I could be wrong. :)

[skullandbones]

Hi Chris,

You can set up a 302 to give you the needed power for your described activity. Mine is designed to "power up" between 4500 and 6500 rpms (personality change at 4500). It drives like a normal car at normal driving speeds. Since it's EFI, it is not much different than driving my DD. If you decide to go with over 400 hp, take a performance driving class and also have your wife do it as well. The problem isn't the extra hp, it's the short wheel base. One of my friends says remember to have it pointed in the right direction when you step on the go pedal. I don't know that many people who have cobras but of that small group two have totaled theirs (single vehicle accident). And the suggestion about the long throttle pedal is an excellent one. It allows you plenty of room to modulate your input to the throttle (not too sensitive). Good luck, WEK.

[riptide motorsport]

All of the above answers are great HOWEVER..............."and also my wife will be driving this car a lot " NOT a good idea. even the tamest of engines in these cars are deadly. If shes going to drive it , get her driving lesson first........PERIOD!

check out this video: http://www.youtube.com/watch?v=B7XkcTgfNzo

[mikiec]

I'm probably on the other side of the coin. I have a basically stock 302. Probably 275-300 at the crank. I do not race it, but have and got it down to 13.1 with 3.27 gears. On the up side over 66,000 miles on it, ave 24 MPG on the road. Can still light up the tires in 1st and 2nd. Faster than 80% of the cars on the road.

The car is quicker than I'll ever drive it.

Mike

[stevem]

FFR,s brochure has a Car and Driver performance comparison with a 325hp 302 and 355s holding it's own with some pretty impressive machines. You can add the 2014 Corvette to that list judging by the specs put out for it in the last Popular Mechanics. Just ordered a 306 from Mike Forte to do just that.

Steve

[firsttimer]

Hi Chris
I have a Dart 302 block stroked to 347. Eagle rotating assembly, trick flow heads and 750 cfm carb that makes approx 440hp. Tremec tko600 and 3.31 gears in a 8.8 rear end (torsen limited slip) and it is scary fast. Didn't put in passenger seat yet as wanted to get comfortable driving it before having a passenger.
Can easily break the rear end loose on demand and cruises at 100km/h at 1600rpm.

very happy with this combo.

Mike

[Pirate]

Thanks for all of the input. I guess I have a lot to think about.

Chris

[DaleG]

All of the above answers are great HOWEVER..............."and also my wife will be driving this car a lot " NOT a good idea. even the tamest of engines in these cars are deadly. If shes going to drive it , get her driving lesson first........PERIOD!

check out this video: http://www.youtube.com/watch?v=B7XkcTgfNzo

Maybe he's married to Danika?

[JL1958]

I have a 302 bored .30 over with a mild cam, aluminum heads, EFI, dynos 280 at the rear wheels. Plenty of power for a car this light.
I will say it is much more dangerous than my last 2 Corvettes because there is no active handling or corrective wheel braking going on. If you do something stupid in this car, you are probably going to lose it.
Oh, and I'm a girl and handle it just fine. :D

[howff]

I have 302 .30 over balanced Bcam performer rpm heads and intake 650dp carb 385hp 365tq (flywheel) t5 trans 3:55 rear car is perfect for all around performance.
These car are all about throttle control.

[2FAST4U]

Anywhere from 350-450 HP is plenty in these lightweight cars

[skullandbones]

Got to ride in a 700 hp roadster yesterday (BBC). Thank God the Nitros was not hooked up. Now I definitely know what is too much for these small cars except in the hands of a very experienced driver. I will stay south of 400 for some time, I think. But the power is addictive! WEK.

BTW: we had three roadsters together and I can tell you one thing about the sound of the side pipes from a side by side. The relatively stock 302 is pretty quiet (around 290 hp). Mine is tolerable except when you punch it. Above 4000 rpms, it's ear plug time. It has 58 cc combustion chambers and shaved heads. The high hp one, you can't stand next to it too long without ear plugs. The point is each car has a different compression ratio and it makes a difference in the sound (stock 9:1, mine 9.7:1, and high hp 10.5:1). I know there is a lot more going on with the BB Chevy but you can feel the pressure from each cylinder firing at the side pipes several feet away. Hearing them live is a lot more telling. If you get the chance do one for yourself. WEK.

[Pirate]

Thanks for all of the input. I have decided to go with the 351. I think it will have just about everything that I am looking for.

Chris

[68GT500MAN]

Your wife will be fine driving your roadster, I know several women who can DRIVE these machines with the best of the boys!
Doug

[QSL]

good brakes, long throw throttle, GREAT tires and a good overall setup is key. We are running a SBF427W rated at 530HP, tko600 and 3.55 rear gears and I have yet to be scared while driving it.

[Bob Cowan]

good brakes, long throw throttle, GREAT tires and a good overall setup is key. We are running a SBF427W rated at 530HP, tko600 and 3.55 rear gears and I have yet to be scared while driving it.

Then you need a bigger engine. :)

You're right, though. A good overall set up is a very important part of the package. These are not snap-tight models. Once you get them assembled, you need to take the time to adjust the suspension and brakes correctly - just like you do the engine. People may spend hundreds of dollars on dyno time to get the engine tuned just perfectly. But they don't spend nearly as much time on the brakes or suspension.

My car makes so much power that I'm stuck in the Unlimited class for time trials. The power to weight ratio is well under 5. The car is v ery easy to driv e, and never does anything I don't tell it to do. And, it does exactly what I tell it to do. I can burn rubber for a block, spin donuts in the parking lot, and drift through most any corner at will. Or, it will just hook up and go. It's very well controlled and very predictable.

There's no such thing as too much power. Only not enough control.

[QSL]

I agree. I need more power lol. Going to point Julie to this thread!!! Lol

[68GT500MAN]

Mike, you will need the extra HP once Julie starts driving the Coupe!
Doug

[QSL]

I just hope she realizes after a couple months 400hp is not enough for her. Then we can put my 427 in hers and I can upgrade to some big boy ponies.

[WIS89]

Mike-

I would be happy to take that beautiful engine off your hands-- just say the word!! She is quite sexy and would look awesome in my Roadster...

I am enjoying watching your Coupe build! You all are doing amazing work!

Regards,

Steve

[Joee]

good brakes, long throw throttle, GREAT tires and a good overall setup is key. We are running a SBF427W rated at 530HP, tko600 and 3.55 rear gears and I have yet to be scared while driving it.

You must not be mashing the pedal to floor on each shift up through 4th. My 302 based build is more than sufficient for street use, yes I can beat any one off the line up to speed limit. Even scared the pants off a guy in his brand new R8 he tried to follow me on one of my favorite local twisty roads.

[howff]

You must not be mashing the pedal to floor on each shift up through 4th. My 302 based build is more than sufficient for street use, yes I can beat any one off the line up to speed limit. Even scared the pants off a guy in his brand new R8 he tried to follow me on one of my favorite local twisty roads.

I agree with Joee on mashing the pedal shift as fast as you can near redline :eek:

[auburn2]

street racing is a bad idea and to woop "anyone" you will need a top fuel dragster.

That said if you are comparing to road cars - 200hp is plenty to drive around with and even there you will be quicker than most vehicles on the road. 350 hp will be quicker than every stock street car out there except bona fide sports cars and 500 hp hp will put you into the super car league with things like top-shelf Ferraris, Corvette ZR-1, Dodge viper and other customized fast hot rods.

This is of course not considering driver skill. As a car gets faster driver skill gets more important. It is a LOT harder to get all the potential out of a high-power car compared to a low-power car. In a 450 hp FFR the difference between a good driver and an inexperienced driver could be 2 seconds in the quarter mile.

Caroll Shelby said "there is no replacement for displacement". That is not exactly true as forced injection is actually a pretty good replacement, but if you are going to stay naturally aspirated a bigger engine will give you a flatter torque curve and be easier and more fun to drive at a specific power point given the limits available in transmission and gearing. Additionally technologies like electronic fuel injection and today's ignition systems make modern cars more "road friendly" while allowing high horsepower.

Given that my initial plan is to use a fuel-injected Buick 455 with a TKO-600 transmission and a 3.08 or 3.27 rear. This is not the easiest nor the cheapest route but it should give me around 470 peak hp at about 5500 RPM and about 530lb-ft peak torque with over 450 lb-ft available from 2200 to 6000 RPM in an engine that only weighs about 70lbs more than a Coyote 5.0 motor. It will be both very drivable and very fast.

[Dale Claytor]

Ford small block 347 stroker, 430 hp 430 lbs/ft torque with a TKO 600 close ratio tranny with 5th gear overdrive, 331 geared moser rear end. Tons of torque and with the close ratio tranny has a strong torque curve up through 4th gear and cruises at 70 mph at about 1800 rpms in 5th gear overdrive. I've only raced once against a modified '07 Shelby Mustang, ate him up. Good luck!

Dale