Whatever_Racecar Endurance 745T

[rb92673]

I thought I would start documenting my POS Lemons car. This forum has been very helpful to me along this journey.

So I bought this 85 745 with B230FT in 2017 to race 24 Hours of Lemons (24HoL). I had originally planned to build a 84 760T that my dad let sit in his backyard since about 1988, but this car was already caged and was almost ready to go.

Car was basic 1985 745T. It had a stock T3 turbo, cut springs and that was about it.

Wiring was in bad shape. Car did not run.

I didn?t really have much experience with wiring or anything outside of basic DIY car stuff. Brakes, changing shocks/springs, exhaust swap out, etc. I found a green book for wiring and started labeling and tracing everything. Since this is a race car and will never see street use again, I started removing unnecessary wiring to make it easier to troubleshoot.

After a while I found things like a missing over-boost switch, fuel pumps wired incorrectly, stuff just disconnected, etc. and it fired up. Seemed to idle and run pretty good, but was running pretty rich. A new FPR and I was ready for a track day to shake it down.

After a few 20 minute sessions on track it had developed an exhaust leak.

Three studs on the turbo had backed out then sheared off.

These were too far to drill out so I found a shop in Santa Ana, CA that burned them out. Jerry?s Broken Drill and Tap Removal. http://brokentap.com/

I replaced the hardware with nice locking nuts and new studs and thought we would be good. Little did I know, but we would have the same exact problem at our first race 24HoL Button Terrible Sept 2017. We didn?t break any studs, but we did lose a couple.

We managed to finish the race, even with a couple hours off track for some repairs. We did have an intermittent power loss that would occur in some corners, we traced it down to a bad splice in the hall sensor shielded wire after the race. Suspension was sloppy, we would find out later the shocks were completely blown out and we were basically just racing on springs.

After the race I removed the engine wiring harness and double checked every wire end to end and made necessary repairs. I also safety wired every stud between the turbo and downpipe.

 

[rb92673]

In March 2018 we entered a true 24 hour race at Buttonwillow with Lucky Dog. Most 24HoL races are really ~14.5 hours with 8 hours on Saturday and 6.5 hours on Sunday. There was about 25 cars running the 24 hour race and we were the slowest one. 6 lbs of boost, but ran for the full 24 hours. With about 3-4 hours left in the race, one of my drivers came in after a spin and said something was wrong with the M46 transmission. Seemed to work fine on upshifts, but downshifts would slip. Probably the one way clutch in the overdrive.

Josh @ Yoshifab is a friend of a friend and has offered me lots of advice in getting the car running and keeping it on track. I told him my m46 was toast and so we used my car for Josh to fabricate parts for CD009 swaps. I found a low mileage JK400 version of the CD009 from a 370z and dropped it and my car off at Josh’s shop.

CD009 with bell housing cut off next to my old m46. You can see how far back the shifter would be in the stock position.

Bellhousing removed from M46 and Deeworks plate on the CD009.

Some pictures of the CD009 in the car with prototype Yoshifab transmission mount. I used a stock pressure plate and a clutch disk that Yoshifab supplied. I also have a temporary shifter that has been on there for four races now.

 

[Harlard]

Hey I saw your car on his lift the last time I was around San Diego. Good going.

 

[rb92673]

Hey I saw your car on his lift the last time I was around San Diego. Good going.

Josh is a super nice guy and really helped me out by suggesting the Nissan transmission versus a T5. We have three full races on the trans now and it has been great. No more crunchy gear changes.

More to come...

 

[patrickstar]

Excited to see the progress, the CD009-redblock swap is on my radar now

 

[rb92673]

A little more on the CD009 swap. Here is a picture of the front half of the drive shaft that Yoshifab had made for me.

The front of the shaft connects to the transmission with spline yoke and then connects to the stock rear shaft after the bearing support with another spline. When testing the shifting, the shaft was sliding too far back out of the transmission and the slide yoke was rubbing on the shifter. This was fixed with by stiffening up the support bearing by filling it with 3M Windo-weld.

Here is my temporary shifter with custom wood shift know.

1-4 shifting is super smooth, 5th gear takes a while to get used to without a reverse lockout.

On the track it is basically an extra gear. Where I used to be mostly 3-4, now I am 3-4-5. I have not used 6th on track.

M46 Nissan
1 4.03 3.794
2 2.16 2.324
3 1.37 1.624
4 1.00 1.271
5 0.79 1.00
6 x.xx 0.794

I now have three full races on the transmission without issues. Over 50 races hours, less pit stops.

 

[rb92673]

We competed again in the 24HoL 2018 Buttonwillow and Lucky Dog 2019 Buttonwillow 24 race. Before the races, we updated the suspension Turbobricks style with some 2.5” 300# springs, on the stock perches. I cut the springs to get to the ride height it was at before. We then put some Bilstein HDs in front and KYBs in the rear. The shocks and struts we had in before were completely blown, basically the springs were our only suspension. I bought some 200# Moog springs for a Ford and cut them down in the back.

The ride is better, but it is not great. I think I need to do a full coilover in the front with shorter inserts and a stiffer spring. Same for rear.

After the Lucky Dog 24, a friend wanted me to come to 24HoL Sonoma. He had a celebrity driving with him and was going to field a second car so that his drivers got more drive time. The celebrity was going to film the race for his ‘reality’ show, so reality sometimes requires re-shoots. I offered to bring my Volvo as it was pretty reliable and I thought it was ready to go.

There was only about 2 weeks between the races, and a few days to go I started making sure everything was tight in the engine bay and that is when I noticed the T3 turbo was leaking exhaust between the hot and cold side. I tried tightening it up, but it didn’t work. Not knowing what to do I ordered a T04E that arrived the day I was supposed to leave for the 8+ hour drive to Sonoma.

I didn’t really know what I was doing, and was unprepared for the larger cold side of the turbo. I managed to get the stock oil and water lines connected and cobbled together some hoses to connect to the stock air box. We left about 2 AM for the race and got through tech at the very last minute. I did not have time to adapt the waste gate activator so I wired the waste gate open. I figured it would run with very little boost, but that was okay.

It was raining in the morning, but my first driver said it felt faster even in the wet. Another driver went in for an hour who was really slow. I put in my third driver and it started to dry up. The third driver came in after about an hour with a blown head gasket. Thankfully he noticed it starting to go and brought it in. Just a slight expansion in the number one cylinder. When I reviewed the video the T04E was developing 12 PSI with the waste gate wired open.

We replaced the head gasket. It’s pretty obvious it’s not the first time the head has been off. We had it back on and ready to go that night. The next day I took the car out for the first time to take the green flag. As soon as the car started building any boost it would dramatically lose power. Check all connections, intake leaks, timing, etc. After many hours we packed up and went home early.

We managed to take a picture with the Celebrity dressed as the Celebrity.

I later changed out the tank pump and AMM.

Some testing determined that was not the problem either. Fed up without any way to troubleshoot other than firing the parts cannon, I decided to install Microsquirt.

 

[Vol242vo]

Are those 2.5 inch coils on stock perches? Do they really seat properly?

 

[rb92673]

Are those 2.5 inch coils on stock perches? Do they really seat properly?

Yes, they are 2.5". No they don't.

I bought some spring perches from Kaplhenke so I could use the stock bearings on top and they sit on the stock perches on the bottom. They rotate and make a lot of noise on the bottom. Not the best solution. They are also cut at the bottom so that doesn't help.

At full droop the spring would come out of the bearing, so I put some ~10# helper springs on top.

 

[rb92673]

I built a Raspberry Pi for my Lemons car primarily for logging, but I have expanded it to do troubleshooting and VE Analyze live. This setup will provide a touchscreen display where you can use Tunerstudio for updates, troubleshooting, logging and VE Analyze live. At my most recent race, my car was running very rich, so I tuned fuel on the track for the first 30 minutes of the race, then used that tune for the rest of the weekend. I also try and log at all times the car is running for later fine tuning.

I started with a Raspberry Pi 3 B+. The Pi 4 was not readily available when I started the project, if I were to start over I would use the Pi 4. I also bought a real-time clock, and 7? Pi touchscreen. The real time clock is useful for keeping the time accurate when you are away from Wifi. The Pi does not have a real time clock. The touchscreen is fine for troubleshooting, but I don't think it is bright enough for use as a real-time dash.

Parts list:

Raspberry Pi 3 B+ or 4
Adafruit PiRTC - PCF8523 Real Time Clock for Raspberry Pi
CR1220 battery
Generic Pi case for your model
7? Raspberry Pi touchscreen
Hardwired dual 3 amp USB power supply
FTDI chipset 9 pin to USB cable
Wireless keyboard with trackpad
32 Gb microSD card

Steps:
I connected the Pi to a computer monitor and USB keyboard/mouse for ease of setup. I used a USB power supply from an iPad to get started.

This video has the whole OS and Tunerstudio installation: https://www.youtube.com/watch?v=KxN5_N_oFEQ&t=692s

1. Install the Raspberry PI Operating System (OS) as per the many instruction guides available such as https://projects.raspberrypi.org/en/pathways/getting-started-with-raspberry-pi
2. Once the OS is installed, turn off and install real time clock, don?t forget the battery. It sits on pins 1-6 if I remember correctly. OS setup is here: https://learn.adafruit.com/adding-a-real-time-clock-to-raspberry-pi/set-up-and-test-i2c
3. Download and install Tunerstudio.
4. Setup tunerstudio to auto-load
5. Data logging\triggered\enabled logging - I set mine to start logging when the TPS is >20%
6. Once you are satisfied everything works, set it up in the car. For the touchscreen monitor I had to connect the HDMI and USB to the Pi for the display and touchscreen, but also the secondary USB to a power supply as the Pi did not have enough power to supply to the monitor. I did not have to install any drivers for the monitor.
7. A USB flash drive is convenient for moving log files and tunes between the Pi and another computer. I have not tried Megalogviewer on Pi.


That?s it.

 

[Harlard]

That's pretty neat. Wanna come up with a CANBUS raspberry pi OLED dash display next? Asking for a friend

 

[rb92673]

That's pretty neat. Wanna come up with a CANBUS raspberry pi OLED dash display next? Asking for a friend

I think there are a bunch of displays you can get for the mega/microsquirt CANBUS already. If you could find a bright screen, you could use the Pi, but it takes about a minute to boot. I don't really want my drivers staring at the screen, I like idiot lights. It is hard enough to get them to come in when the oil light goes on.

 

[rb92673]

So this happened at my last race.

Had a lot of other failures as well including wideband O2 sensor and in tank pump died.

Also checked the bearings of my old race engine with about 9 races on it.

I don't know much about bearings, but I don't think they are supposed to look that way.

 

[itb-volvo]

Cars looking good. I'm sure your learning this but it seems to always be something with these lower buck endurance cars. After 12 years of running ours it's still something just about every race. As a side note you should try and make the LD race at Sonoma this February. The General Leif is planning on being there. The more Volvo's the merrier.

 

[rb92673]

Cars looking good. I'm sure your learning this but it seems to always be something with these lower buck endurance cars. After 12 years of running ours it's still something just about every race. As a side note you should try and make the LD race at Sonoma this February. The General Leif is planning on being there. The more Volvo's the merrier.

Thanks, I think the General Leif is amazing.

Previous to this car, I had never done anything more than basic maintenance. Since then I have replaced, repaired or modified almost every part of this car.

I am doing 24HoL Buttonwillow this weekend and Sonoma in December. I will take a look at the LD race.

 

[rb92673]

Well not a great weekend racing at 24 Hours of Lemons at Buttonwillow. Got there early enough on Friday that I signed up for test day. At the last race I broke the hotside of my T04E, so I ordered a China T04E as a temp replacement. It lasted two laps, than boom and huge smoke cloud.

The shaft between the turbine wheels snapped. I probably didn't oil it enough?

It also was overboosting a ton.

Anyways, got it back together with my old turbo with new hot side in time for raceday and was experiencing lean conditions and low boost pressure. Never really figured out what was wrong, but in the end I changed fuel pressure regulator, filter, swapped brand new pumps, and in tank hose. No idea. Finally at the end of first day I had stable fuel pressure. I disconnected the wastegate just to be safe for the next day.

Race day Sunday car ran good with reduced power. All the drivers got two shorter stints and took the checker.

 

[rb92673]

Fast lap at 24 Hours of Lemons Buttonwillow September 2021.

https://youtu.be/oTFAvCvYdLw

 

[klr142]

w00! Thanks for the link to the thread.

Sweet transmission!

Sorry about the turbo issues. I wonder if the exhaust and it's current hanger/hanging situation is putting additional weight/stress on the downpipe?

 

[122power]

Cars looking good. I'm sure your learning this but it seems to always be something with these lower buck endurance cars. After 12 years of running ours it's still something just about every race. As a side note you should try and make the LD race at Sonoma this February. The General Leif is planning on being there. The more Volvo's the merrier.

The 24HOL is almost half the cost fyi for sonoma 1430 vs 2200. Lemons does the bus stop though.
Probably more volvos in lemons vs LD id say. 745t above, 242t, 780t, 244v8, 245 bernal and my 245na.

 

[rb92673]

w00! Thanks for the link to the thread.

Sweet transmission!

Sorry about the turbo issues. I wonder if the exhaust and it's current hanger/hanging situation is putting additional weight/stress on the downpipe?

I went 6.5 hours without a Turbo failure at the last race. #winning