Sexy!
Sexy!
I'm jelly over those pulleys. If you think you want to upgrade the pump on your intercooler, I have a Bosch pump that is for a lightning/cobra I can probably let go for a challenge friendly price.
Now we needed to connect the throttle body and add some sort of air filter. If you look at this picture with the supercharger and manifold mocked up you’ll notice that there isn't a lot of room to put the throttle body and get air to flow through it.
Our solution was to remote mount it. We also had a couple of adapters made up when we had the intake manifold and intercooler welded. You might have seen them in an earlier photo.
They have the bolt pattern from the original supercharger/throttle body interface with a short tube connected to them. Then we could connect them with a section of pipe. I walked around a junkyard looking for an air filter to mount to throttle body. I eventually found one on a Chevy Trailblazer with an I-6. After a little mocking up and bracket building combined with some flexible pipe we have this:
Then we had to finalize the serpentine belt and routing. We figured out that we could add an idler pulley to the power steering pump bracket. Bracket:
Mounted to power steering bracket:
We attempted to start the car and after fixing a couple of wiring issues the car started and idled... at 4,000 rpm. Well, that won’t do. It turns out that the flexible tubing isn’t really rated for vacuum. It’s intended more for brake ducting. At this point time was running out in the semester and we all had finals to prepare for and reports and presentations to do. So we called a halt to further progress. Here is a picture of all of us on senior design project presentation day:
From left to right: Matt, me (Sean), Elias, and Kyle. We all got good grades and graduated. I towed the car home and parked it outside my parent’s house. And it sat there waiting while I moved, got married, started a job, and bought a house. About a year later I finally got the car to my new home and started updating the build thread. So that, finally, brings us to the present. Except for one thing...
It seems that I’ve made the current issue of Grassroots. And from reading the little blurb it appears that I need to finish this car and get down to Gainesville this October. Talk about motivation. So look forward to some more updates as I replace that flexible tubing, get the car running and tuned, paint it, and finish all of those other little details.
Short update: I had a little free time after work and the temperature outside was actually above 20°F. So I cleaned out the trunk and decided to chip away the rest of the sound deadening.
Then I popped the hood and removed the flex-tubing part of the intake system. I’m left with this:
I need to connect the throttle body on the left with the inlet on the right side of the supercharger. I already have flanges on both ends with 3” diameter tube welded to them so I think that my best solution is to get some 3” exhaust tubing and cut and weld until I get something that fits. Then get some silicone adapters for either end.
Despite the lack of updates I have been making some progress. I finished re-plumbing the intercooler system with hose that is compatible with antifreeze. And I also plumbed in a coolant overflow bottle / fill point for the system. It’s out of some mid-90’s GM product.
I also made it official. I’m going to make it to the challenge this year. Unfortunately I had to enter in the exhibition class. Remember how I told you that getting the intake manifold welded killed my budget? Well, it took the very experienced welder 9 hours to do it. And at $65/hour shop rate that works out to a grand total of $585 out of my budget. I still need to do some more digging rules-wise and get my budget up to date, but it looks like I’ve run out of challenge budget. Lots of things left to do. But first I need to finish off the intake system so that I can get to tuning MegaSquirt. Then I can put on all of the new brake components and maybe paint the car.
Plan A:
Learn to weld
Copy manifold using scrounged aluminum
Sell original
Recoup!
Plan B:
Find and experienced welder who works for beer
See plan A (start at #2)!
Or recruit, train or kidnap a welder to be a team member
It’s been 2 months since the Challenge. I suppose that it’s about time that I get this thread up to date. First up, I needed to make up a hard pipe to connect the throttle body to the inlet of the supercharger. I was running out of time and didn’t have a welder. So I mocked up the pipe that I needed with some 3” diameter, bendy-straw brake ducting. I wrapped it in tons of packing tape hoping to immobilize it.
I found a local truck exhaust shop that was willing to convert this to metal. I made up the mounting flanges to weld to the ends and marked their orientation. They got something tacked together and gave me a call. They really wanted to have the car to mock up with before final welding. Well, you see, this presents a problem. The car didn’t run, and I didn’t have access to a truck locally to tow it the 15 miles to the shop. But I did know someone with a tow dolly and my daily has a hitch. A quick hitch up and some pushing and pulling with the lawn mower and we get this:
Incredibly sketchy setup overall. The dolly was homemade and didn’t have a pivot mechanism. So I had to leave the steering on the BMW unlocked. Then, seeing as the Saturn barely weighs more than the BMW acceleration, braking, and turning were compromised. I took my time and as many back roads as possible. Then turning into the muffler shop’s gravel drive the weight of the BMW shoved the back of the Saturn sideways. Oversteer while towing a trailer! Not good. I made it out ok. The muffler shop then asked that I move the BMW into the garage.
Somehow I managed to back up that whole setup into their garage. They test fit the tack welded pipe and were literally off by maybe 5° on one of the three connections. They said it was one of the best mock up models they’ve had. Anyways, the muffler guys finish welded it and I asked them to cut a ½” section out of the middle. This was for a silicone joint to accommodate the vibration of the engine mounted supercharger vs. the frame mounted throttle body. $150 later and this is mine:
I managed to make it back home safely and returned the dolly. I cleaned up the intake pipe and painted it a nice flat black. After it dried I bolted it up and started messing with MegaSquirt to get the car running. Man, is it ever a steep learning curve. But the msextra.com forum was helpful and I got it to start and idle. Unfortunately, it was a 4,000 rpm idle. Ouch. More to come in a minute...
My Dad was kind enough to drive over from Fort Wayne quite a few nights in a row before the Challenge and helped me fix the idle. It turns out that the fancy intake manifold didn’t have a perfectly flat mounting surface for the supercharger. The air was leaking around that and causing the runaway idle even with the throttle fully closed. He took a straight edge and file and hand filed the surface as flat as possible. Thanks for the help Dad! Then we made up a new gasket out of some nice thick, compressible cork.
After bolting it all back together the car fired up and idled at a more reasonable 1,500 rpm. I’ll take it. Unfortunately, it wouldn’t make boost pressure.
Meanwhile, I had decided on a paint scheme and started laying it out on the car. My Dad, father in law, and I began the endless task of masking off the silver paint that was to remain. Thanks for your help guys. We went through so many rolls of tape. But we end up with this:
Anything in blue would remain silver, and any exposed silver would be painted what I was calling John Deere Racing Green. Tractor paint is about 1/3rd the cost of automotive paint. After we finished with the supercharger (the Saturday before the Challenge) we spun the BMW sideways in the garage and we got to masking off everything else. Trim, windows, wheels, and the garage walls. I put in some drop sheets to make the garage smaller and easier to heat.
I gave the painted surfaces a quick scuff with sandpaper and then wiped it all down. Sunday I mixed up the paint, reducer, and hardener and loaded up the spray gun that I borrowed from my Dad. Much green filled the air (serious green fog. I need to ventilate better next time)
It was so tempting to un-wrap the car then, but I waited until after work on Monday. That left me with this:
Not bad for my first ever automotive paint job. No runs and only a little bit of dust. But it just didn’t pop like I wanted. I got some 1/8” black pin striping and started putting it on every green/silver division. In the end it took more than 100 feet of pin striping and until Tuesday evening. But I like the result much better.
I even painted and stickered up an old license plate to support my employer.
So we have a car owned by a Cooper Tire employee, running on Kumho tires, in a competition sponsored by General Tire. Oh, the conflict of interest! :) I also added an additional badge to the rear, even if it wasn’t working properly.
I dedicated some more time to troubleshoot the no-boost condition but didn’t have any success. Wednesday night rolled around and my parents arrived with the crew-cab Tundra and car trailer. We got the race tires put on, loaded it onto the trailer under its own power, and packed up the tools. Dark and early Thursday morning we took off on the 1,000 mile drive to Gainesville. It took a considerable 19 hours. Next time we make it a two-day trip! Needless to say, we immediately went to bed and fell asleep.
Friday morning we got the car unloaded at the track and successfully through tech. I figured out my boost issue. I didn’t have the correct circuitry built into MegaSquirt to control the boost control solenoid. I tried a few things but ending up just running the car without controlling it. So I had a naturally aspirated car with a supercharger fan/restriction on the intake. It was just as much fun as I remember, but the automatic transmission is still a drag. I let one of the professional drivers take it out for the last 3 of my autocross runs.
Feedback from the pro included convert it to a manual transmission (in the works, I just need a clutch and flywheel) and get some nice, stiff springs. Unfortunately, on the last run the power steering/supercharger belt slipped off. We were able to fix that before after the autocross and before lunch. Note to self: redesign the pulley system to make assembly and tensioning easier and better. Also, align pulleys to prevent belt throwing. We ended up with a best time of 47.126 seconds. Good for 27th overall. Mid-pack. Not bad considering it’s basically a stock E30 with some aftermarket springs and old Kumho Ecsta XS tires. After dinner was the drag racing. The automatic was most definitely a downside here, especially since I forgot to lock down the kick-down cable. It shifted with all of the speed of an octogenarian with a bad back. Even with that it was a ton of fun. I’d never gone drag racing before and I can definitely see where the addiction to go faster comes from. I got a best time of 16.701 seconds.
Combined I got a 63.827 dynamic time which gave me a dynamic score of 83.7 out of 100. This was 28th overall. Saturday was the concours. We arrived, got everything cleaned up, removed the hood, and set up the poster display from the senior design project on the windshield. I ended up being the first car to be judged. They seemed impressed and just as disappointed as me that I hadn’t gotten the boost control to work. I also got lots of compliments on the paint job. I got a score of 15.7 out of 25, good for 11th overall.
I enjoyed meeting everyone and seeing all of the other competitors. And like everyone else, I ended up with some gold bling from the Aristocrats of Team Déjà vu. I especially loved the Camaro from Team T-bone. I grew up on the Gran Turismo games.
And who could ignore the humongous smile on Team Suprang in the 1973 Fiat 850 spider as the car just leaned around every corner. I love how he blew his budget on the googly eyes for the headlights and how comically small it was compared to the Crown Vic parked next to it.
Saturday night was the awards banquet. It was certainly cozy. There was one picture in the pre-dinner slide show that I really loved. It was a rear ¾ view of BMW on my first drag run. The sunset lighting combined with the drag strip disappearing into the horizon was beautiful. I’d love to have a copy of that photo. I was also glad to be there to see the Nelsons finally win the Challenge overall. Congratulations guys!
My scores put me in 16th place overall. I’ll consider that a success. Do I wish I had done better? Yes. Do I wish I could have welded the intake manifold myself and not gone over budget and been forced to be in the exhibition class? Absolutely! But I’m proud of what I did accomplish and happy that I got the opportunity to show everyone what I can do.
During the concours Mrs. Shawnee Creek kept mentioning how she wouldn’t mind if we competed again next year, and how she liked the “Soccer Mom’s Revenge” that the Aristocrats wanted to do next year. We talked it over on the way home and kept tabs on the thread as it progressed on the forum. Then we walked through the local junkyard looking at possible vans. We ended up getting a Chevy Lumina APV and a Pontiac G6 GTP. You can read all about that here.
Thank you all for taking the time to read through this thread. And thank you GRM for putting together this competition for us crazy people. We had a wonderful time. And I look forward to competing (or at least watching) with the APV GTP next year. -Sean
Thanks GRM for the photo hosting. I went back and fixed all of the pictures.
Two years later and I still have this in the garage. I've drug it along with me, but really haven't worked on it much. We did finish the "van" and won the Soccer Mom class with it.
I'm considering selling the BMW though. It's going to need some work before I can take it on a racetrack again and I haven't had much interest working on it. Even if I did get it running, I'm not sure I want to take it out on track.
I really enjoyed building it and learned tons of things along the way. Maybe I can pass it along to another Challenge competitor with the budget sheet. Without the supercharger and its related systems it is a $500 car that is nearly rust free. I need to give it some more thought though...
Well, I made up my mind. The BMW is up for sale here on the forum. $2018 for it and every part and document associated with it. I've created some great memories with this car, but it's time to give someone else the chance to do the same. I hope that I can pass it on to a GRMer.
-Sean
And it's on its way to it's next home. I wish the new owner the best and hope his plan of taking it to the Challenge works out.
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