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Thank you very much. I have wrapped parts of my exhaust, where it is close to adjacent parts, and put a heat shield under the trunk. I don't expect miracles from the turbo blanket, but everything helps. I ordered the blanket.
I was also thinking of putting a small ducted fan on each air inlet pipe that comes from the roof scoop. The small ones that boats use for engine compartment ventilation. I've used them previously for Cobra footbox cooling.
A real pain to get at that, but glad you found it and sorted it out. But...............20 volts?
You saw it. 20 volts at 3 of the 4 wires attached to the fuel relay. Must get stepped up somewhere. The fuel pump probably draws quite a bit of constant power.
I saw 20v, but am skeptical. You might want to check your battery voltage on the 600V DC setting and again on the 20V DC setting. I suspect the meter is mis-calibrated on the higher range.
Seeing how much effort you put into getting to your fuel pump, I hope mine never gives out. Thanks for the videos.
RPG
I thought the same thing. I think I've read that the control may step down the pump voltage under certain conditions, but increase it? I'm skeptical as well.
Wow, not sure what to think. I used a ton of those type solder connections in my wiring harness... which crimp connectors and crimp pliers are you using?
I had an intermittent fuel pump failure on my R. Sometimes the fuel pump would power up when power was applied, other times not. My issue ended up being the variable speed fuel pump controller. Because my car is used exclusively at the track, mostly at high engine loads, I did not replace the expensive variable speed controller, and simply installed a switched relay to the fuel pump, which now runs all the time, when power is supplied. The advantage of the switched relay for me, is that it allows me to crank the car (at starter motor speed) to build oil pressure before I let the engine run. This is useful for me because my car sits for weeks at a time between track days. I hope yours was the connection, and that the problems are behind you. There is nothing more frustrating than a car not starting when you expect it to....It's especially frustrating when you've paid $300 for a track day and your car won't start....
Measured my battery on 3 DC settings and the 600v setting is a few volts off. Not a problem when I was testing the relay for power (it was going to be yes or no) but it is slightly inaccurate for measuring lower voltages. Funny enough, it still only read 15v at the battery where my fuel relay was seeing 20-21v. FYI my fuel system is stock except for the Boyd fuel tank + Aeromotive Stealth 340 pump it comes with. Maybe my tuner changed some fueling settings that increased pressure/draw?
600v
Attachment 187850
200v
Attachment 187854
20v
Attachment 187853
I'm using a pair of electrical pliers I bought from Home Depot a decade ago. I bought the crimp connectors at AutoZone. I used solder seals across my entire car and I've had a driver window issue, this fuel pump issue, and my car occasionally won't crank (until I push around some wires underneath the dash and play with the clutch switch... I think it may be the clutch switch sticking... once the car is running it has no issues). Rob, I almost missed my autocross heat last weekend because my car wouldn't start. It was only $65 but I feel your pain!
Attachment 187852 Attachment 187851
Did you check for continuity across those solder connections you cut out?
I essentially did that in the video where I moved the fuel pump wires and then the pump got power. Moved the wires again and the pump had no power. Moved the wires again and the pump got power. But, I dug the old solder seals out of my garbage and did a continuity test for science! They are showing the wires are connected. However, I haven't had the fuel pump falter even once since I replaced the solder seals 6 weeks ago. Including my autocross last weekend where everything got a good shake down. I'm confident the solder seals were the source of my fuel pump issue.
Attachment 187903
Hard to argue with the evidence, but the just doesn't make any sense. When you used the solder seal, did you twist the wires together before sliding the sleeve over and heating, or did you just slide the wires inside the sleeve and heat?
Continuity tests with a multimeter typically use between a microamp and a milliamp to measure resistance. Any bare metal contact at all between the wires will give a low resistance reading. If the contact area is tiny, a fuel pump pulling 5 amps will overheat that tiny area causing it to oxidize around the edges until there is no more bare metal contact, and no more current flow. Wiggling the connection can cause the wires to abrade the oxidation and touch again for a while. A good crimp makes the wires touch in a large enough air tight area to prevent heating and oxidation. A good solder joint will do the same.
I just stuck the wires in and heated the sleeve. The connection worked flawlessly for 2 years so there was a good, solid connection. The sleeve has a glue inside of it that holds the wires in place and I've confirmed the wires have not been pulled out any. So the only reasonable explanation is that something changed where the solder is connecting the 2 wires. The solder has cracked, crumbled, oxidized, corroded, something.
I gently cut open a solder seal and sure enough, the solder has cracked and separated. I thought the solder would have penetrated the wiring a little better but you can see a lot of copper on the black wire.
Attachment 187905 Attachment 187904
Twisting the wires together before you seal them would be better, but you'll still be relying on crumbling solder to a degree. I wouldn't recommend it. Several people have told me these get brittle and stop working after a couple years and now I agree. I will only use crimp connectors from now on.
I also remember Wayne from Very Cool Parts recommending crimps over solder in an old thread. He's built plenty of cars, tracks them, and is a professional mechanic. I think that says something.
Attachment 187906
Case closed.
I've never used them, but it seems to me that it is a compromise design. Solder generally melts at a much higher temperature than it takes to heat-shrink a sleeve. I wonder if they use a low temperature melting solder and a high temperature heat shrink? You are trying to melt solder through heat shrink sleeve. I've never had an issue with soldered connections with a heat shrink sleeve applied after soldering. I use crimps as well, with a crimping tool like you use. Everything I've read says to never use one of those, use a proper ratcheting crimp tool. Someday I should get one.
It is a very low temperature solder, I would not be surprised if the heat introduced by the amperage of a fuel pump would compromise it.
I do use the solder sleeves, but I always twist them really good and fold them back on themselves before I put the sleeve on, and I'm basically only using the solder to help keep the twist/fold tight. I definitely see how just sliding them in and heating them would be problematic. To be fair, that is how they advertise them, but I never trusted that method. I prefer to use double crimp connections for all of my connectors (see link below), but they don't make a splice using those, so I have stuck to the solder sleeves around tightly twisted and folded wires. When you do it that way, you have to go one size up on the solder sleeve, so it's not a slim solution.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
If you are going to splice, you really should go with aerospace style PDIG splices from a reputable source such as:Quote:
Originally Posted by Ajzride
https://bandc.com/product-category/e...s-and-splices/
These have one piece (not split) barrels that are long enough to take the double crimp from a tool like this:
https://bandc.com/product/pidg-style-crimp-tool/
These crimpers make two crimps at once - one on the conductor and another slightly larger crimp on the insulation providing both a gas tight connection and strain relief.
Ed
I've read through some alignment threads but most are a decade old. What are the specs you guys have been running or found to work best? I'm getting my car re-aligned on Wednesday to hopefully get my car to feel less darty/nervous and a little more planted during turns. Going slightly more aggressive to help with autocross also, but this is mainly a street car.
Current specs
If I'm reading this right, I have one toe in and one toe out on the front? It's not much, but I would think that could contribute to some of my steering nervousness? I think this is basically zero toe but I would like them both to be facing the same direction, toe in.
Attachment 188361 Attachment 188362
I want to go to these specs, but any suggestions? Again, 90% street car but also some autocross.
Front
-1.2deg camber
+5deg caster
1/16" toe in
Rear
-1deg camber
1/8" toe in
Those specs should be fine for a street car, if the alignment shop can get them there. I've been away from my project too long but I seem to remember having to modify the UCAs to get there (but that might have only been for early chassis).
Yeah I saw that early builders had to cut some pieces or add spacers to get high caster and camber. Wasn't sure if that was still an issue with the later kits like mine from 2020. Guess we'll find out.
I noticed between my first 2 alignments that 4deg caster was better than 3deg. So I'm going to focus on higher caster and add a couple extra washers to my bump steer kit to try and work out the last bit of bump steer.
I have 5 degrees of caster, 1 degree of camber, 3/16 toe and the car handles great for street driving. I have the Baer bump steer kit modified to accept large spacers, so I have almost no bump steer (this was critical for the roads where I live).
Thanks for the reference AJZride!
I added 3 washers to my bump steer kit to bring my total spacers up from 21mm to 27mm. This is the most I could add to the Baer kit without modifying it. The car is significantly less nervous already. I must be getting close to same travel path for suspension vs steering. Adding these also increased my toe in though so that may be helping. I have my alignment appointment tomorrow morning and will report back.
Attachment 188531
Similarly, my front specs are; 6deg caster, 1.5deg camber, 1/16 toe
I also added all the washers I could to the Baer system and don't notice any bump steer, though I'm unfamiliar with it so may have some.
Got the car back from the shop with the new alignment. As expected, they maxed out a couple adjustments. Front camber is maxed at -1deg and caster is maxed at +4deg. With the added caster and extra spacers on the bump steer kit the car is significantly calmer. Every little steering input doesn't make the the car dart in that direction and the steering wheel is finally starting to pull back to center a little bit after turns. Bump steer is gone for most driving but large bumps/bridge transitions still give the steering wheel a little shake. Much improved and worth the time and money. Still not as good as a production car but this is closer.
The car is already easier to drive on back roads but the true test will be this Sunday at autocross. We'll see if I can close the gap to those pesky Miatas with my modest alignment changes. While doing my research I learned that increasing caster also gives you more negative camber while turning. A nice side effect. So maybe I'm effectively running more than just -1deg at the front wheels during turns. Hoping this helps my front end stick better! It's my limiting factor right now.
Attachment 188648
I also had a CEL pop up this week for the air pump valve. I cleared it and will see if it comes back. I deleted most of the air pump system so hopefully this isn't actually effecting anything.
Attachment 188649
One can only appreciate so much from a driving video. My guess from your video is the limiting factor in cornering is oversteer. If the back was holding better you could go faster.
As mentioned by Sgt Gator previously, setting up the rear lateral links is critical to snap oversteer. They must be equal length forward and aft. Right to left is not critical.
With that, you could explore more front anti-roll bar influence. With the Subaru/FFR bar you do not have many options. Modification of arm length can create more effect.
Higher front spring rate is another possibility.
jim
I was watching the autocross at Sonoma earlier this year. They had a "dynamic" course. If a cone got knocked out of position, it didn't get fixed so the course evolved throughout the day! Obviously, the children were in charge (not saying that's a bad thing).Quote:
Originally Posted by mcamera
It's hard to tell from the video but I'm actually getting understeer. My front wheels give up first and the nose pushes through turns. I've increased camber on the front wheels (went from -0.7deg to -1deg) and increased the caster (+3deg to +4deg) which also adds camber during turning. Hoping that transfers more weight into the front end for more grip. I've considered disconnecting my front sway bar also.
That would be interesting with the cones moving around every run! When my times stopped decreasing I started wondering if I clipped a cone and they added a +1sec penalty. I don't think I did but it's hard to tell when you're driving.
It's not an easy thing to master and might have less of a benefit at the lower speeds of autocross, but trail braking will help keep weight down on the front tires and significantly aid in your ability to grip and turn in. I've been practicing this technique on my simulator and it is super effective when done correctly. Also, since you are in second gear the entire time, you could left foot brake which might help a bit.
I like to walk the pits and see what tires everyone is using. What are those Miata's running? Tires make a HUGE difference.
Do you have a limited slip differential? It makes a big difference in pulling out of a second gear turn. Do the Miata's?
I see some understeer going INTO turns. That understeer might be that you are doing some trail braking with too much front brake bias. Your stop at the end of the first run and other places too looks / sounds like too much front bias. Maybe find a stretch somewhere and get your brake bias dialed in. If you switch up tires, recalibrate your brake bias. It also explains your comment. "the front wheels give up first". If your front tires are squealing the way they are as you brake for a turn, the squealing probably means loss of traction as you tun in due to the brakes locking up so easily.
All excellent suggestions. Everybody I've talked to is running 200 UTQG tires. My Kumho's are 460 and most people have said switching to 200's dropped their times anywhere from 3-8 seconds! I've been comparing myself to the stock classes because they're limited to street tires (no slicks) and can't make many modifications. That way I can see if I'm gaining on cars that are the same every race when I modify something.
I don't have an LSD so I occasionally spin 1 wheel in sharp low speed turns. I think I would benefit from one but I also think stickier tires would be enough to eliminate those spins. I have modest power from a stock EJ25 tuned to 275hp/300tq and the longer gears of the 5spd.
I meant to play with my brake bias this weekend but forgot. I was distracted by my new alignment which has made my car way grippier than I expected. I didn't think I would notice a difference because my changes sounded small, but the car has come alive. I had a lot more control and speed in the slalom, the front end doesn't push any more in hairpins, and I'm able to get tail happy if I get on the gas too soon at exit. This was a huge leap forward and now the car feels as sharp as I always thought it should. Results will be shared in one of my next videos.
Attachment 188785
My buddy let me borrow his set of Longacre scales to corner balance my car and I'm shocked at what I found. I didn't realize how poorly balanced my car would be. I thought corner balancing was one of those "squeeze the last 2%" out of something deals. My ride height was 4.5" at each corner (within 2mm of each other) but apparently even ride height doesn't translate to a balanced car.
First off, my friend's track car. Pretty cool little single seater with a 1200cc Yamaha engine.
Attachment 189036
Here's the set of wireless scales w/ tablet. He also let me borrow 4 of these red tools to measure ride height. They stick magnetically to the bottom of the car and give you an easy read out on top.
Attachment 189037 Attachment 189035
Here are the car's weights without me sitting in it.
- Front 43% / Rear 57%
- Left 50% / Right 50%
Attachment 189038
And here are the readings with me sitting in the car
- One of my rear wheels has 200lbs (26%) less weight on it. This might explain why it's so easy to do a 1 wheel peel. With no LSD, once 1 wheel spins I lose acceleration.
- Even with me in the driver seat, the LF wheel has 130lbs (23%) less weight on it than the RF wheel. During a hard turn I can only imagine 1 wheel gives up way sooner than the other. Not using both front wheels efficiently.
- The left wheels have a 300lb (43%) difference
- The right wheels have a 0% difference
- The diagonal and cross weights are 43% / 57%. Far off from 50/50 as you want.
Attachment 189034 Attachment 189033
Final results after adjusting my coilovers
- Front wheels are 5% different (old 23%)
- Rear wheels are 6% different (old 26%)
- Left wheels are 25% different (old 43%)
- Right wheels are 24% different (old 0%)
- Corner weights are 50/50 (old 43/57)
- In the end my ride height is ~10mm higher on the passenger side but my body is level and measurements from the fenders to ground are similar. Build differences + the hand welded chassis probably has some warp.
Attachment 189032
The difference when driving is huge. It turns with so much more confidence and accelerates with less sliding now that both back wheels are working together with similar grip. The ride has gotten noticeably stiffer now that all 4 shocks are loaded evenly. I can't wait for autocross next weekend. I'm expecting big results.
Very cool equipment and interesting findings. I felt the same way you did, that corner balancing was a final tuning that really didn't have major effects. I'm also surprised that it doesn't take much change in ride height to make significant changes in corner weight.
Does anybody else feel like this is optimistic? The crank pulley is the same diameter as the OEM pulley so it still has to produce the same amount of torque to turn the alternator on our cars (and maybe the AC for some people). You can make the pulley lighter but to say it reduces so much rotating mass (-4lbs) that it's equivalent to 100lbs off of the curb weight sounds like a stretch.
Attachment 190276
Marketing to sell a very high margin item :-)
I never heard of any equivalency for rotating mass. We did road race SBF with aluminum flywheels saving weight and rotating mass. The result was faster free revving with no load. Helpful for rev matching downshifts.
jim
I have that pulley in red in my 818. It looks way faster.Quote:
Originally Posted by mcamera
Mike, I do not recommend installing a lightweight crank pulley. These are fancy looking, but do not serve the function that is intended for the crank pulley. The OEM crank pulley is a harmonic balancer. Those lightweight ones do not harmonically balance at all. If you want to swap your crank pulley, look into an a Fluidampr Harmonic Balancer or an ATI Super Damper. The Fluidampr is superior, but more expensive. Both will be significantly more expensive compared to the lightweight options, but will actually help your engine rather than hurt it. Talk to any reputable engine tuner and they will tell you the same thing. If you cannot afford a Fluidampr or ATI Super Damper, just keep the stock balancer/crank pulley (which is what I did). At stock power levels, the OEM balancer does just fine.Quote:
Originally Posted by mcamera