Fuel system getting a slight rework due to fuel starvation on longer left handers still. I've tried new fuel socks but it didn't solve the issue so I'm going to a little bit more excessive of a solution.

Fuel pressure sensor because I only had an analog gauge before.



Will wire up to the nearby spare connector.

Radium Fuel Pump Hangar.





Feed line marked with tape so I don't forget what line is what.

Replaced the radiator hose with a Dayco 71519


Need to make new brackets for the Aim Dash

 

You should wire up the second fuel pump in the radium hanger, either just as a spare or triggered off low fuel pressure.

 

Not a bad idea. If I was building a w2w car or something where position actually matters, I might be more inclined. Just as a TT car though, I don't think I really need to add on the complexity of a dual pump setup yet.

 

Remote adjusters so I can adjust the shocks without having to unbolt the wing and open the trunk up.


New longtube headers



Wiring for the fuel pressure and GM 1bar MAP sensor


Relocated the oil cooler to behind the radiator for ease of packaging.


New radiator ducting with bolts/nuts instead of rivets and a 3" naca duct for brake ducts in the future.


Extended the Singular Motorsports aim dash bracket with a PLA test print of support braces and sun visor. Will reprint in ASA before the first track day.


Mounted the coolsuit to the interior of the car.





Was having some TPS issues which I thought were connector related so I backpotted a TPS connector with tefzel, MG832HD, and a DT connector.


Turns out I had somehow pinched the signal ground wire and severed it inside the insulation. When signal ground was disconnected, the signal wire would be basically become the ground, sending the TPS signal to 100%. If the car wasn't on, it would activate flood clear mode and prevent the car from starting. If the car was running, it would just run like **** because it was in the wrong part of the map.

Dyno run with the new header and 3" exhaust. I own a TDR rotrex now, which is what the 3" exhaust is built for, but I'm holding off on putting that on for a bit since I want to see if I can take more of the n/a BP lap records in CA. I currently hold the Laguna, Thunderhill West, and CVR CCW lap records, but want to grab a couple more before boosting.
162hp/133.48lbft, solid gains in the 5500 rpm region and above which would be nice on track.

 

Jeeze man, your updates never cease to impress. Your attention to detail is noticed, especially on things like the TPS backpotting and your connectors. Good work, and very solid numbers on the NA BP, that things gonna RIP with some rotrex air shoved into it! I salute you for staying low power for now, it's something I wish I would have done.

 

I agree with Fire, this is the kind of build thread that makes me want to do better work on my own car. Really nice work man

 

Thanks for the kind words!

 

New splitter with diffusers.



Center Exit temporarily finished


Trying 225 CR-s


Aim sunshade and mount braces printed in ASA.

 

Bought a 2006 LBZ Duramax Chevy Express 3500 van to tow with so I had my own rig instead of having to borrow my dad's 1500 Yukon XL. This thing is a beast, ~6600lbs completely unloaded, ~22mpg if I'm driving the speed limit, ~14mpg towing a ~2200lbs trailer and ~2200lbs car, and all my stuff. I can barely feel the tow package behind me, and I can fit so much stuff inside. The previous owner also had a murphy bed welded in so I have a sleeping platform that can just fit a full sized mattress.

 

Yeah, that van is sick. Nice buy.

 

Test day at Thunderhill after the new tune and aero tweaks.


Session 1, the splitter cable came apart and let the splitter drag on the ground, pretty much deleting the front corner. It hadn't been an issue before, and I hadn't touched in, so I'm going to wish that the tunnels are doing something. Relatively easy fix of making a new cable and torquing it down some more.



Session 2, the car died on track on an off-pace yellow flag lap and I had to get towed back in.



Went through the troubleshooting process and was unable to figure out what had happened. The car would crank and just not start. It had air, fuel, and spark, so I had no idea what was happening.
Packed it up after around 6 hours of troubleshooting in like 95deg+ heat because I was just getting frustrated with no progress.


When I was home, I kept getting crank position errors, so I thought it was a timing related issue, but I was getting solid oscilloscope traces and supply voltages.


Just as a freakout moment, I had thought I had somehow melted a hole in the piston or something, so I scoped the cylinders but I had pistons that looked like pistons.



Turns out the root cause was the GM MAP sensor I had put in had failed and was constantly reading -14.7psi and the car was in the wrong spot in the map and wouldn't start/run. I didn't have any vacuum hose on hand, so I taped together some bits I had lying around and re-enabled the built-in Haltech MAP sensor, and the car started first try.

 

I was still encountering fuel starve, and there was a notion that a massively the oversized 450lph walbro I have in the fuel tank is overpowering the stock 626 FPR. Replaced the FPR with an adjustable Radium unit and took this opportunity to relocate the fuel filter/flex fuel sensor from inside the trunk to outside the car. I don't love this location still, and I might move it again in the future. Had to use an AE86 fuel rail 6AN adapter for the NB rail.







Also confirmed that the fuel tank internal passenger side baffle was still present.


Built another splitter after the previous one disintegrated at THill.


Actual final exhaust exit with trim that finally arrived.

 

Loaded up for MTTC #5 at Streets.


MTTC corner


I was still fuel starving out of corners, with a full tank of fuel so it wasn't a pickup issue. Unplugged the vac reference from the FPR and zip tied the line back on itself and those issues went away. Who knows how long my issues with fueling have been vacuum reference related.


Friend got a couple of good photos of me/the car




P2 in mod class.

 

Trailer must have picked up a shred of tire or something on the way to MTTC Rd 6 at BW Circuit and broke the fender.


Van with bed set up, chair, and cooler, with room to spare.


Testing day with @DUDELOL, and I had to put bigger end plates on to balance out the more aggressive front splitter. I don't like how this looks, but it keeps the car from being extremely sketchy at speed.


MTTC headquarters


I also unplugged the brake booster for much better brake feel. I definitely prefer unboosted brakes on track.




Car/driving was only good for P2. I had better corner speeds than P1 in pretty much all corners, but there's only so much I can do against a car with 100hp more on a course with this many straights.

 

Had a weekend of wiring failures at THill west. Its getting to a point where I want to remake my harness to fix all the things I think I messed up the first time around and do it better the second time around.

I had used a terminal for 10-12ga wires for my fuel pump hangar, and I guess I didn't crimp it well enough. Fixed it with some autozone terminal and some extra filler wire.



Additionally, the IACV wiring failed, but I just adjusted the idle screw enough until it was idling without IACV.



Lighting was good though, and I had some fun with friends at the end of the day in the dusk lighting.






Accidentally drove off the track because I was looking at my mirrors for @icantlearn but no damage was done and we had a good laugh about that.

 

Garage for the final MTTC 2025 round at Buttonwillow CW13. The track itself is in absolutely terrible shape, with the bumps way way way worse than ever before. The rain in previous weeks also didn't help and had washed away any rubber that was on track.




SpeedVentures is interesting because some of the clientele has some serious money but can't drive the cars fast, which leads to some amusing hot pit lineups. I was the fastest in my run group, visually very out of place compared to the rest of the photo.




P1 in Mod class, P2 for the season. Good enough for a PB too, but not by much.



Group Photo

 

SIck updates. Love the vids, what camera are you using? Has a nice sense of speed.

It's crazy how quick you can end up off track at pace if you are checking a mirror, or even have a momentary loss of concentration, etc. Been there. As always, I love this car and you are doing it justice as a pilot!

 

DJI Action 5 with ND filter on an Amazon rollbar mount. You have to turn stabilization off otherwise it tracks weird, but otherwise I like how the footage looks and the sound is acceptable enough to not require an aux audio setup. I don't even have a wind muff on it or anything.

 

Lessons learned re: failures? Just poor crimping?

 

Yeah, better crimping, and more importantly, much better strain relief. All my failures have been strain related where wires are bending past what they can handle and its seemingly always at a transition point between sheathing and wire or at another hard junction where I didn't put in enough strain relief.