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Discussion Starter · #1,242 ·
I'm not crazy! I had a chance to get my car on the original dyno for a comparison of the new tune. The first photo is the original tune and I was sure that there was more in the engine. The second tuner found the "more" I was expecting by working around a glitch in the ignition timing parameters of the Megasquirt. This tune was done on a roller dyno so the readings were different. The second photo is from yesterday: notice the torque curve is flat and strong from 2500rpm, and we gained more than 20hp.





The new oil pan seems to be doing its job, and now I have 2 weeks to get ready for racing at Barber in Alabama.
 

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Discussion Starter · #1,244 ·
Good observation... yes the torque at low and midrange rpm is very different. 40-50 lb-ft.

It's making more torque at 2500rpm than it did at peak on the original tune. The Megasquirt software has a glitch that will be rewritten when I leave my car at DIY for a week. With a "workaround" (second ignition table) the new tune allows 20 degrees more timing advance and the engine needs it even at low rpm.
 

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Is that like 40 more ft lbs through a fat band? That's like a whole extra Honda of torque. Plus the area under the curve got so much bigger, that's gonna be a lot of usable power.
Well technically, all the torque it makes currently is exactly one Honda-worth...
 

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One modern Honda! I think he was talking about 90s era Hondas lol

Wow, that is a pretty awesome torque curve for a 4 banger. Even before the vtech kicks in its pretty decent, some seriously usable power there. It doesn't exactly blow away the old motor, but it certainly matches or betters it every where now and does it with way less weight and better cg. You're going to be fast at your next event!
 

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Discussion Starter · #1,247 · (Edited)
After a frustrating first day of racing with Champcar at Barber yesterday, today was a spectacular way to send off the first racing chassis - Grumpy Butt is being retired to be replaced by GB2. I'll write a full recap when my brain cells start working again.

Summary: Saturday we had electrical issues that took us out of 5th place overall, then late in the day I felt a "clunk" in the rear when letting off the throttle. It turned out to be a broken right rear hub. We replaced the right rear control arm before Sunday's race and nearly won. Not bad considering that the transmission was stuck in 3rd gear for the final three hours.

Ready for a new day



8 hours later in impound



Hardware!! 2nd overall and winner of class B

 

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Discussion Starter · #1,248 ·
Champcar Barber Race Weekend - December 12-13, 2020

It was a weekend of lows and highs. The new chassis is being prepared for the transplant of drivetrain and suspension, and this was going to be the last official race of Grumpy Butt (Mule). I couldn’t find a person to crew so Mike, Nabil and I would be “working drivers” during every pit stop. With a good strategy we were able to fuel and get a driver into the car in 3 minutes, leaving 2 minutes to check oil and clean the windshield.

One new factor that came into play this weekend was the use of a “Code 35” Flag. Barber had a recent incident with a safety crew getting hurt and decided that there would be no “hot pulls” during the weekend (dead cars are removed from a section of track under yellow flags while the rest of the course is still at race speed). Each time a car died on track this weekend the Code 35 flag was displayed at every corner station, which meant that all cars were to maintain 35mph and maintain the same distance to the car in front of them. The new flag created positive (Sunday) and negative (Saturday) situations for us.

Grumpy had some new items to claim in the budget so I drove to the track in the early afternoon Friday to go through Tech again. I added the S2000 header and the aluminum oil pan which both should have added points to my budget. It turns out that you can use any OE header for free as long as it came from a car on list of legal Champcar vehicles. The oil pan added 25 points which brought me to 480, well below the 500-point limit.

Staging and tech were done in a large parking lot outside the track while a Porsche driving school went on inside. Tech went quickly so I had a few hours to kill before the paddock opened at 5pm. It was fun watching tech and chatting with friends, and checking out some cars that I’ve never seen up-close. I saw some things that I might want to incorporate into my new car. At 5pm we were allowed to enter the paddock and we got the car ready and the pit set up.

Saturday
After a great test day at Barber with Just Track It in November I didn’t have much work to do to get the car ready for the Champcar race. I installed new front brake rotors and pads (cheap rear pads never seem to wear out). There were a couple of small oil drips from the transmission and diff but nothing serious enough to worry about. With 4 new tires mounted we were ready to go. We started the race in 15th with Mike in the car. The weather was drizzling to start and never dried out all day, there were just different levels of rain. Mike drove for 1.5 hours and got into 6th place before a Code 35 flag for oil on the track. It seems that someone oiled the entire track so a truck with a large tank of liquid soap was sent out along with a large sweeper.

That turned into a Black Flag All and all cars were brought into pit lane (no work could be done on them). Drivers got out of the cars for an hour while the cleaners slowly made their way around the track. The driver clocks were reset so we put Mike back in and he drove another hour. We got a Full Course Yellow and put Nabil in the car – Mike had only used 12 gallons of gas in 2.5 hours of rain driving.

Nabil made about 20 minutes on track before the car died. After a tow back into the pit the car started running again so we sent him back out, only to have the car die on the first lap. We had him towed to the paddock this time and started diagnosing the problem. At first we thought it might be a fuel problem so we replaced the fuel pumps and sent him back out only to have the car die again. This was the negative part about the Code 35 flag – every time we were towed in all other drivers had to go 35mph for at least 2 laps so I felt bad for taking their racing time away. After a third tow we started looking for an intermittent electrical problem. We started moving wires near the ECU and finally tracked the issue to the white connector of the MS3. After 30 minutes of playing with wires we couldn’t make it die any more so I took the car out. I still have no idea what the problem was.

After 20 minutes in very wet conditions the car was running fine but started clunking when I let off the throttle. It started getting worse so I came back to the paddock. We jacked up the car and started looking for the source of the clunk. I’ve had issues in the past with diffs, driveshaft u-joints, and even a rear crossmember bushing that disintegrated. I found the left rear crossmember bushing had broken off the poly “flanges” and the crossmember could move vertically about ½”. I sent Mike and Nabil shopping for window weld (it worked in the past for the same issue). They came back with a stack of large washers, a tube of window weld (urethane) and some steel the make end plates.



Thirty minutes later we had cut a couple of endplates, filled the bushing space with washers and window weld and bolted it in tightly. We would have to wait until morning to see if the urethane “set” and would do its job. Earlier in the day another team mentioned that the right rear wheel looked to be wobbling, but it had no bearing play and the lugs were tight.

Sunday
I took the car through the paddock slowly and the first time that I let off the throttle the clunk was still there. Dammit.

We jacked up the rear end and started searching again until Mike mentioned the wobble in the right wheel. We pulled the wheel and removed the brake rotor to find a broken hub – this was the real problem. Fortunately, I had a spare control arm with a hub installed so we replaced it in 25 minutes and got Nabil to pit lane before the start of the race at 8:30am.



The track was still a bit damp from the previous day but started drying quickly. By 10am there was a dry line and lap times were dropping. We caught a well-timed caution to pull Nabil in and fuel the car, then it was my turn to drive. Nabil had driven us from 30th to 7th place. This was the positive about the Code 35 flags on Sunday – it was much easier to catch slow laps where we could dive into the pits for fuel and not lose too much track position. There have been races run with NO full course cautions and teams gamble with pit strategy that could make or break a good finish.

I was next to drive and would go about 40 minutes until “Quiet Time” – a common Sunday happening at race tracks where all cars are brought to pit lane under Parc Ferme rules. Drivers got out for an hour and no work could be done on cars. In a first for me personally, I was the driver with the Fast Time of the Day in the race to that point, which led to a very humorous hour in our pit. There are apps for phones where you can follow races with live timing and most teams are glued to them during a race. When a car turns their fastest lap of a day the time will show up in Green rather than white. When a car turns the fastest lap of the race it will display in Purple. As I was getting out of the car Mike yells “nice job Mr. Purple”. This set off an hour of laughing as we watched the naming scene from Reservoir Dogs. Go look it up, I’ll wait…

OK, maybe you had to be there. Anyway, we were in 5th overall at this point.

At 11:50 I got back in the car for the restart at noon. I was about 30th in line so there would be a lot of traffic for a while. After one lap behind a pace car we were set loose again. The car was running great and only one car got past me (a C4 Corvette). The Supra is such a joy to drive that I wanted to stay out until the fuel tank went dry, but we had a strategy that opened “windows” of time and if a Code 35 was displayed I was supposed to come in a bit early. After an hour I pitted in 2nd place overall and Mike took the wheel. I checked the oil and we cleaned the windshield then sent him off.

On his second lap he took my Supra FTD with a 1:43.2 and I knew he’d only go faster if traffic allowed. Unfortunately, the clutch decided to stop disengaging not long after that and he couldn’t shift at all. To make matters worse the radio in the car died at the same time so the last message I heard was “something broke” before silence. He jammed the transmission into 4th gear and kept racing, and actually turning respectable lap times that probably would have kept us in 2nd until the end of the race. 20 minutes later Mike must have gotten tired of feeling slow because he decided that 3rdmight be a better choice of gear to race in.

He waited until just before “pit-in” during a Code 35 lap and attempted to get the transmission into 3rd in case something went wrong. On video it looked reasonably smooth but he never touched the shifter again. Mike turned some stellar laps considering that he only had one gear, and even passed the leader to get us on the same lap. The engine hit the rev limiter at least three times each lap, but there are no “slow” corners at Barber so he didn’t lose much time where a downshift to 2nd would help. Fortunately, there are no long straights either. Mike would hold the throttle in a position to hold rpms just under the rev limiter and maintain as much speed as possible.

With 2 hours to go in the race we prepared for the final pit stop. Mike knew the situation and pitted when a Code 35 came out within our window. Nabil barely got any driving time Saturday so I gave him the second Sunday stint. He shifted the car into 3rd before starting the engine and somehow made it down pit road, stopped so they could remove the timer that Champcar uses to monitor pit stops, and started driving. This is the worst time in a race for me – waiting for something bad to happen… for the next 105 minutes. The outside edge of the left front tire had no tread but I didn’t tell Nabil. Mike thought it would be fine.

I can’t sit still and watch what happens so I started breaking down the pit stall, cleaning up the paddock area from the repairs, and organizing my truck for loading. We had a tire and tools ready for a quick change, and a fuel can ready for a splash and go if necessary. We believed that the fuel would last even with all of the high rpm running. I checked Race Monitor occasionally and saw that Nabil was running laps between 1:43 and 1:47 depending on traffic, so as long as the car stayed in one piece we could finish strong. Mike was right about the tire, too, it lasted until the end. With 15 minutes left I checked to see if any B class cars could catch us in the time left and there were none close. 5 laps from the finish Nabil ran the FTD for the Supra at 1:42.7… with 3rd gear only!

The car survived the thrashing to the end and we finished in 2nd overall, 35 seconds behind the leader. Impound and trophies followed along with a well-deserved beer.






Mike Sunday Stint with the start of the clutch problem.



Nabil finishing the race.

 

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Wow! Epic race and same for your previous races! Congrats to you and your team especially recovering to 2nd overall. Maybe someday you can compile all your race stories into a book. Thank you for representing the A60 Supra! I look forward for the next season episodes ;)
 

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Discussion Starter · #1,251 · (Edited)
Awesome! What a great debut for the new tune, that is one fast race mk2!

Racing breaks the damnest things for sure, I've certainly never managed to break a hub.
We posted that hub photo somewhere on Sunday morning and Dave in NJ posted an identical photo of a Cressida hub (same part) that failed on their race car. This is his photo:

 

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We posted that hub photo somewhere on Sunday morning and Dave in NJ posted an identical photo of a Cressida hub (same part) that failed on their race car. This is his photo:

Yes, We experienced a similar clunk on decel and since my failure was on the left side I started experiencing a clicking noise in right turns, and at NJMP Lightning has a really long high speed banked right hand sweeper that really loads the LR.
 

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Discussion Starter · #1,254 · (Edited)
After the car finished the Barber race I thought that it would be easy to replace the clutch and be almost ready... not so much.

The new clutch and flywheel went in easily and the transmission seemed fine during a low speed drive. The clutch disc was causing all of the disengagement problems at Barber. I had to reuse the one that was damaged when the flywheel bolts came loose - the friction surface was fine but the metal plate between the friction material was compromised and finally failed around a spring (notice the three pieces of metal that fell out). The rivets were already beat up by a broken flywheel bolt. Exedy was having problems supplying the specific disc I use so this was all I had at the time.



A friend borrowed my headlights for a 24-hour race last summer and he liked them so much that he kept them. He paid me and I ordered a new set of Dynamic Diode "driving" and "wide" lights. I had to add extensions to my light bar and rewire the entire system to the trailer plug. I'm looking forward to seeing them outside at night.



At 3 different races we have had questions about fuel pressure causing problems and replaced fuel pumps in an attempt to fix them. Only one time was fuel pressure a problem and we wasted a lot of time switching pumps at the other 2 events. Hopefully that won't happen again with the addition of a fuel pressure gauge. The sensor mounts in the fuel line with AN fittings and a quick glance will tell if there are pressure issues.



 

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Discussion Starter · #1,255 · (Edited)
To get clearance for a coolant hose under the intake I removed the boss that held the OE serpentine belt tensioner. The KMiata pulley simplified the belt to the crank, alternator and water pump, but the "tensioning system" has never thrilled me. When the belt gets loose the intent is to space the alternator away from the water pump with washers.

I stared at pages of belt tensioners all weekend and finally came up with a fairly simple solution. I used 1/8" steel plate and two of the OE motor mount bolt holes. The plate is slotted for adjustment, as is the idler which is a timing belt tensioner pulley from the original Toyota engine. It's not spring loaded but an adjustment should last an entire race. I welded the idler bolt from the back and ground it down for clearance.





 

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Is that a Glow shift Fuel Guage? I recently installed their diff temp guage and I'm pretty satified with it for the price. I want to install a fuel pressure guage as well. we had a bad lean condition at our last race in NH and replaced everything (filter, pump) and it ended up being the regulator.
 

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Discussion Starter · #1,257 ·
It is a Glowshift - seemed like a good price for the entire set-up. If it fails it doesn't affect anything related to racing, we would only lose a diagnostic data point.

I'm interested in your measured diff temps. Do you have any type of cooler or added oil volume? I believe that my 2 diff failures have been heat related in long races, and installed the diff cooler to alleviate the issue. I still don't have a temp sensor.
 

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There are (one use) thermal tapes used to measure surface temperature of metals.

Thermax 6 Level Mini Strips - Measure-Tech
To measure the actual temperature of the diff oil, drill and tap a fitting into the fill plug to connect a temperature probe. Glow shift one could work.
300 F. is when the oil breaks down?
Adding a diff oil cooler could work without a pump, relying on the spinning motion of the ring gear to circulate the oil through the cooler. In or out from the bottom with a banjo fitting.
230 F. is maximum.
Is your IRS differential overheating? You may need a differential oil cooler. (maximummotorsports.com)

Differential oil cooler - Bing - Shopping
 

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It is a Glowshift - seemed like a good price for the entire set-up. If it fails it doesn't affect anything related to racing, we would only lose a diagnostic data point.

I'm interested in your measured diff temps. Do you have any type of cooler or added oil volume? I believe that my 2 diff failures have been heat related in long races, and installed the diff cooler to alleviate the issue. I still don't have a temp sensor.
I did add a cooler, pump much like yours, added the glowshift short sensor in an -AN tee (didn't have time to weld a bung directly into the diff cover) so I read temps coming out of the diff when the pump was running. I built it into a steel box with a naca duct with an inline blower for insurance. without the blower the hottest it got on a 90deg day on a shorter course was 185. with the blower it dropped below 160. The cooler and lines brought total capacity to just over 2 qts. I cooked 2 diffs in one weekend prompting it.
I am now running the True trac I burned up and had rebuilt by Zuk with new ring and pinion with a REM process. Gear Install Toyota
 

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Discussion Starter · #1,260 ·
I also run a fan but it's mounted on the cooler, and my capacity is the same as yours. It's nice to see your numbers under 180 degrees.

I remember pulling a broken diff during a 24 hour race at 2am (14 hours into the race - broken teeth on the R+P). At 6am it was still hot to the touch!
 
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