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Project E-Mod MGB-GT


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  • 4 weeks later...
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Recap: At Nationals, the higher grip levels revealed a problem with lifting the inside rear tire and locking up the rear tires. I determined that this was due to the left rear tire having 90 lbs less weight on it than the right rear. To correct it, I moved the battery, fuel cell, surge tank and overflow tank to the left rear side and also moved the intercooler and radiator. Here is a shot of the scales before I did all that:
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And now after I have made the moves
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As you can see, there was significant improvement in rear weight bias, left/right balance and overall weight.  I now have 54.3% weight over the back tires and almost 50/50 left/right balance. This should make the car accelerate, turn and stop better.

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When I purchased my transmission, I thought the 82 mph in 3rd gear would be perfect for Nationals because most people agree that we hit 80 mph on the courses. However, I found out pretty quickly that 1st was a little low so we would start off in 2nd and use 2nd and 3rd only. There is a 30 mph spread between 2nd and 3rd and it would take a moment for the power to come up again. Also, several times on course, the car would either be redline in 2nd or lugging in 3rd. I looked at other available gears available for the Super T10 and found one that will work much better. It has a useful 1st gear that is good for 45 mph and a 23 mph spread to 2nd gear and another 21 mph spread to 3rd gear. This should result in better acceleration and more choices of gears on track. It was way cheaper to buy a new gearset than a new transmission so that's what I did. Attached are pictures from a speed calculator for the old gearset (3.42 first gear) and new (2.64 first gear) plus a picture of the actual gears.
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  • 4 weeks later...

Update: My transmission has been sent off to a shop to get the new gears put in and I have hired Kyle from the Kyle Drives YouTube page to help me with the aerodynamics of the car. He is currently modelling the Pink Panther in 3D CAD so he can do a Computational Fluid Dynamics test on it. We Skyped for a while and he has looked over pictures and video of the car and has already given me some suggestions on what to do. Everything he has suggested is easy to do but he is going to do a CFD run before and after the changes to see how big the benefits are. He liked what he saw so far and I'm happy I have not made any big mistakes with the aero. Here is his YouTube page, and he is as friendly as he seems in the videos: https://www.youtube.com/channel/UCh3tzzP6n5b1EWcMUpiEhXg

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So much has happened this year, it's impossible to cover it all. At the first WSCC event I attended this year, the transmission seized and the shop who built it is blaming the gear vendor, and the gear vendor is blaming the transmission shop.

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I bought a new transmission with the correct ratios and drove down to a test n tune and event in Lincoln, Nebraska. The car was awesome on the test course and we were easily the quickest thing out there, but my stock oil pan did not agree with the long, high G sweepers and we damaged our rod bearings, so we packed up and came home without even competing.

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I bought a low mile EBay motor that arrived looking like it had been rolled down a hill, into a lake. The cam cover, cam gears and chain were crushed and the insides were all rusty. 

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The EBay seller replaced the engine immediately and had it at the parcel service in 3 days. It was a mad scramble to get it in the car before SpringNationals but I got it just in time. We got to Lincoln and went out on the test track. The experience was underwhelming. I can't describe the car as slow but it clearly had lost some of the snap it had before. It also understeered way too much but anything I did to correct that resulted in tire spin from the inside rear tire. I tried different rear roll center and front sway bar settings but didn't correct the problem. This was upsetting because the car didn't seem to have the ability to get a podium finish, let alone win anything. I sent the data log off to Jerry from Bad News Racing and he suggested that sometimes the wastegates are a little soft and I could tune that through settings in the computer. I made the tune changes and magically found the missing boost pressure. Since I was already on the test course, I decided to try some different shock settings and tire pressures. These worked surprisingly well and the car felt pretty good for power and handling. It still understeered slightly under some circumstances and still spins the inside rear tire a little but both seemed manageable. 

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The car felt pretty good for day 1 of competition. My first run was a little herky jerky and I hit the brakes too early a few times but I cleaned it up for run 2 and it was good enough to be sitting in 3rd place. On my 3rd run, I knew as soon as I let the clutch out that something wasn't right and noticed the boost gauge was not moving. I did my best but the power wasn't there. On the test course, I experimented with some wastegate settings to get boost back where it was supposed to be. We did 8 runs this way and nothing went amiss. On Day 1, overboost occurred and triggered the car into limp home mode. After the event, I cleared DTC's and boost came back. Jerry from Bad News Racing sent me a new tune that is less sensitive to overboost and gives me a little more timing for extra torque. I keep trying to add a link to the video but this forum gives me a "403 Forbidden" message. I've tried hotlinking and tried just posting a link but nothing works. 

 

 

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We loaded the new tune for day 2 and Briget came back from her first run reporting that the car was "F%&King Fast!". I went out on my first run and didn't push hard because the course was really confusing on the course walk and I wanted to make sure I knew where to go. My time was slow and I dropped a number of positions but felt I could make that up on my 2nd run. Sadly, I had no boost again on my run and was really slow, and only Briget was slower. She was having her own issues with not pushing hard enough and braking too early, a result of the car being a lot better this year but our brains haven't quite realized it yet. I re-loaded the new tune for her 3rd run and logged the data. She had boost for her final run but as a precaution, I cleared the DTCs and loaded the tune again. I felt immense pressure because nearly the whole field was ahead of me and I had to pull one out on this last run, and hope I had boost for all of it. I took off from the start and boost was definitely there, I tried to take my mind off what the car was doing and just drive it. I felt like it was clean and I rolled to the scales to get my weight. I had no idea if I had a good enough time to get 3rd place back and didn't know until a competitor came over to congratulate me on my 3rd place. I was surprised and pretty happy about it. These were the top drivers from EMod and I managed a 3rd, despite my problems.

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Craziest dyno experience happened today. I need to remind or share a little background info first. This EBay engine has been randomly going into a limp home mode, which means no boost. And neither the old engine or this one would make any boost at all below 4000 rpm. The wastegates on these engines are set for a really low opening pressure (6 psi) so for the last event I just added a spring to the arm of the wastegate and it upped the opening pressure to almost 9 psi and it made boost at 3700 rpm. For the dyno session, I added more spring pressure and it now opened at 12 psi and was fully open at 20 psi. They strapped my car down like normal and I warmed it up then shifted up to 4th gear and mashed the throttle. The car started to rev then violently went to redline, like the tires were spinning or something. It turned out that my new for 2017 ceramic clutch was slipping under load in 4th gear. Right there on the dyno, I removed the trans to adjust the hydraulic release bearing and put it back together. This changed nothing, it still slipped like mad (see YouTube video) so Brian Wall suggested I try a pull in 3rd gear. Since this was just a test to see if the clutch would hold, I didn't start the GoPro, but I sure wish I had because it would have made for an unbelievable video. I stomped on the gas in 3rd gear, boost came up, the front tires came right off the ground and the car danced around the dyno-it was crazy!! While they double strapped the car down, I looked at the data logs and the car was making 10 psi by 3000 rpm and peaked at 31 psi. On the next run, when I was actually able to go all the way to redline under load, the car was breaking up from being too lean. Jerry from Bad News Racing was hooked up remotely to my laptop so he looked at the logs and saw that the throttle was actually opening just 50%. I was making a lot of power for just 50% throttle opening. Just to be sure, I disconnected the extra spring on the wastegate and we tested again. It wasn't as lean as before but it also wasn't making the boost and the throttle was still only 50% open. Jerry made more changes and we tested and re-tested but only had moderate success with the throttle opening problem. Then the fuel pump solenoid, which controls the high pressure fuel pump, failed and put the car into limp mode. We found our problem. There was no point testing further because data logs showed that the solenoid was not allowing the fuel pump to get to the pressure it was supposed to. Fortunately, I have a spare solenoid, and I have another clutch so I hope to make it to the next race event. I would link the video but this site won't let me.

 

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So the last event was a bit of a disaster for me. On the Friday before I was on the dyno to try to get more boost at low rpm because I had been making zero boost below 4000 rpm. During testing, my 69,000 mile fuel pump (the one that is supposed to pump 2500 psi) failed, which would explain why the engine kept running lean. I put another fuel pump on Saturday and came to the Sunday event. During my first run the car felt good at first but quickly started to break up at high rpm and was way down on power. On my 2nd run, it felt like it was running on 3 cylinders and on my 4th run it felt like it was on 2 cylinders and I had to shift to 1st gear where I should have been able to leave it in 2nd. I got it back to Speedworld and performed a compression test and discovered that 2 of the cylinders have only 30 psi compression. I stuck a borescope down there and the video clip of that is included here: 

 

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  • 1 month later...

At the last TNT, the car felt better than it has ever felt before (new springs and diff) but after my 2nd run it was overheating. It made no sense because the week before I had it on the dyno and it never overheated. I got it back home and checked the usual things and it should not have overheated. I did a leakdown test and it passed with flying colors, and did a pressure test on the cooling system and that checked out, too. I finally pulled off the front cover and discovered that the chain that runs the water pump had snapped-problem solved. 

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Here is video from the Test N Tune

 

And this week I ported the head

 

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  • 5 weeks later...

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