1985 Volvo 740ti - GRM 24 Hours of LeMons Racecar

For vehicles not yet running, but in the process of converting to MegaSquirt (ask a moderator to move your thread once you are running).
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gielamonster
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Joined: Tue Jun 22, 2004 4:13 am
Location: Hermosa Beach CA
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1985 Volvo 740ti - GRM 24 Hours of LeMons Racecar

Post by gielamonster »

The event is a month away and the car is (hopefully) days away from firing up on MS-extra. I'm using a discarded v1.01 (yep, you heard right! circa 2001) PCB, completely fresh harness built using everything stripped from the stock harness plus some 1/2 off day junkyard parts. Grand spankin total of this MS conversion is under $50 easy, $25 of which was the boost control solenoid. Here she is in all her glory:

Image

I'm just starting to realize some challenges of using the V1.01 PCB, namely all of the extra manuals are written for 2.2/3.0 users. Granted, the 1.01 is very similar to the 2.2, so I'm hoping they're similar enough that I can get things working. Might just require a little extra digging through the wiring schematics on my part.

The car is an '85 740. No need to double-post car stuff to this thread, I'm trying to keep this one over on turbobricks.com updated:

http://forums.turbobricks.com/showthread.php?t=85444

The project will also eventually have a more permanent home on my website:

http://www.evilengineering.com/

and the GRM project cars pages. Here's a picture of the car we started with to keep it interesting:

Image


Anyway, here's the plan:

MS-extra running fuel & spark
stock fuel system
stock turbo
hacked stock exhaust
vb921s running waste spark through a JY neon coilpack
EBC
ms fan control
sequential shift lights

Nothing all that exciting. Its a 13 hr endurance race, and this car was already better power/weight than the bulk of the field when it was stock. Then we stripped it down near 2200lbs and we'll turn up the boost to a conservative 225-250 to the wheels. Plenty of go, but not so much that we'll be worried about popping stuff.

I'll post my updates and questions here, so I invite you to keep checking back!
gielamonster
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Posts: 19
Joined: Tue Jun 22, 2004 4:13 am
Location: Hermosa Beach CA
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Post by gielamonster »

Car finally ran last night. Using trigger return crank timing scheme caused my coil outputs to hover high and only drop to ground for ~approx the specified dwell. Switching only that setting to time based cranking instantly fixed the problem and inverted that signal without juicing the coils with the motor off. So maybe my trigger return settings were off, but for now I'm just happy I can fire it up.

Took a bit of fiddling to get the trigger angle indexed correctly, but once it was the car fires up on the first crank or two and runs very smoothly. I connected the WBO2 after it ran for a while last night and began working on the map. Hopefully we can get it close on the quiet streets of the industrial park we're working in, then really fine tune it with some free dyno time next week.

Here's a video of the first drive last night:
http://video.google.com/videoplay?docid ... 0452703301

And some recent photos of the car:
http://evilengineering.com/gallery/v/gi ... v/stretch/
gielamonster
MegaSquirt Newbie
Posts: 19
Joined: Tue Jun 22, 2004 4:13 am
Location: Hermosa Beach CA
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Post by gielamonster »

Anybody getting excited yet? You'll notice GRM has picked us up on their project car pages...

here

Still needs some tuning, but the car is running/driving/handling great. Feels very quick. One tire fire through 3rd gear pretty easily. Thats at 8psi, we'll run about 14 in the race if I can get it tuned well enough. Might need to rig up a "push to pass" though, as the car has plenty of nuts to power out of the corners right now.

Latests photos from before this weekend...

Image
Image

We're keeping the final pre-race photos under wraps until after the race, don't want to blow all the suprises.

If you're at all close to Tracy CA and free this weekend, you owe it to yourself to come watch the most spectacular, horrific, action packed racing you've seen in a while. Just repeat this out loud to let it sink in "A 13 hour car crash." Thats the long and short of it. If you make it out come swing by our pit and say hi. GRM will be there with us, they'll have swag too. Come root us on and stuff the ballot box in our favor for the People's Choice award.
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