not building boost???
11-06-2010, 10:50 PM
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not building boost???
Just got done putting the 930 back together and have been working out a couple bugs, finally got to take it out on the road! I can build rpm's to 3 or 4k but as soon as I add a little throttle pressure to get into the boost the car immediately bogs really bad. Idles great but wont take anything more...
A little history, added twin plug ported heads, another crankfire coil pack and extrudohoned intake. I run Rice style fuel enrichment and have the car rough tuned at 1% CO. Electromotive advance is set up +5deg 0-3000 rpm, +24deg 3000 to 8000 and -10deg 8000+ rpm. Currently a Kokeln Turbo, GHL headers. The Turbo is spinning and the car runs great until I push it to take more fuel. Too much fuel? Too little fuel? Any thoughts on tuning this setup GREATLY appreciated!
A little history, added twin plug ported heads, another crankfire coil pack and extrudohoned intake. I run Rice style fuel enrichment and have the car rough tuned at 1% CO. Electromotive advance is set up +5deg 0-3000 rpm, +24deg 3000 to 8000 and -10deg 8000+ rpm. Currently a Kokeln Turbo, GHL headers. The Turbo is spinning and the car runs great until I push it to take more fuel. Too much fuel? Too little fuel? Any thoughts on tuning this setup GREATLY appreciated!
11-06-2010, 11:07 PM
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Substantial mods. I presume it was running fine prior to the mods? Could be something as simple as a badly leaking IC o'ring. Do you have confidence that your ignition timing is controling properly? 24 degrees advanced timing is a bit much at full boost (unless your stated timing is without boost, then it's ok). You wouldn't happen to have on-board AFR monitoring....would help determine if fueling is way off. Are you running with stock or modified WUR. And what is "Rice style" fuel enrichment"? On the surface it sounds overly rich to me.
Lots of variables here to sort out....sorry, no simple response but I'm sure you'll get the input needed eventually.
Lots of variables here to sort out....sorry, no simple response but I'm sure you'll get the input needed eventually.
11-06-2010, 11:38 PM
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Mark,
It was running fine prior to the new mods as well as before I had a bad 964 cam/rocker that needed replacing (clogged spray bar) and the rest was simply sitting on my kitchen counter... Funny how that works with those thinks that work just fine but could be better... The rice fueler is a modded wur, precursor to the Bleask and adds fuel through the wur on boost. Haven't been able to get anything but 0.0 on the LM1 to date, another small project... I had the HPX coil packs tested and they checked out as well as my timing light reflected the ignition settings. O rings are new and doesnt run at all like theres a vaccum leak at all. Seems like a fuel dump to me as well but with only 1% co I'm a little leary of backing it off any further. Do you run crankfire/twin plug as well? The timing numbers seem to be consistent with a lot of the guys that run this setup. Gonna have to really hunker down on the LM1 bugs I suspect.
It was running fine prior to the new mods as well as before I had a bad 964 cam/rocker that needed replacing (clogged spray bar) and the rest was simply sitting on my kitchen counter... Funny how that works with those thinks that work just fine but could be better... The rice fueler is a modded wur, precursor to the Bleask and adds fuel through the wur on boost. Haven't been able to get anything but 0.0 on the LM1 to date, another small project... I had the HPX coil packs tested and they checked out as well as my timing light reflected the ignition settings. O rings are new and doesnt run at all like theres a vaccum leak at all. Seems like a fuel dump to me as well but with only 1% co I'm a little leary of backing it off any further. Do you run crankfire/twin plug as well? The timing numbers seem to be consistent with a lot of the guys that run this setup. Gonna have to really hunker down on the LM1 bugs I suspect.
11-07-2010, 09:57 AM
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Hah! Most always something simple. Hope a new relay solves your pump problem.
No, I'm not running the exotic mods that your are. Just these: 1987 930, LSD, B&B Intercooler, K27 7006 turbo, Tial WG, Kennedy Stage 1 PP, HKS boost controller to 1.0bar, BL adjustable WUR w/boost enrichment delay, LC-1 AFR and G3 analog gauge, Greddy boost gauge, MSD6AL and 8762 boost retard ignition, K&N cone air intake, Fabspeed dual outlet muffler
I'm running with a lot of initial ignition advance (about 12 degrees) but shave it off progessively as boost builds to end up with about 18 degrees by full boost...for safety sake with whopping 91 octane gas. Your 24 seems on the edge, but then this territory is still being explored by many as I feel the wizzards at Porsche built in a fairly large safey margin in their design - or at least we hope they did!
My Bleask WUR is soon to be replaced with a DIWUR, just waiting for me to get motivated and do the swap.
Best of luck on solving your problem. Let us know if you get her sorted out.
No, I'm not running the exotic mods that your are. Just these: 1987 930, LSD, B&B Intercooler, K27 7006 turbo, Tial WG, Kennedy Stage 1 PP, HKS boost controller to 1.0bar, BL adjustable WUR w/boost enrichment delay, LC-1 AFR and G3 analog gauge, Greddy boost gauge, MSD6AL and 8762 boost retard ignition, K&N cone air intake, Fabspeed dual outlet muffler
I'm running with a lot of initial ignition advance (about 12 degrees) but shave it off progessively as boost builds to end up with about 18 degrees by full boost...for safety sake with whopping 91 octane gas. Your 24 seems on the edge, but then this territory is still being explored by many as I feel the wizzards at Porsche built in a fairly large safey margin in their design - or at least we hope they did!
My Bleask WUR is soon to be replaced with a DIWUR, just waiting for me to get motivated and do the swap.
Best of luck on solving your problem. Let us know if you get her sorted out.
11-07-2010, 08:13 PM
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Yeah, a fuse. Did the fuel pump circuit upgrade and the fuses are the push in type and are no longer on the relay board. Got boost and it eally seems to move out. Now for the tuning part...
Regarding timing, I'm actually pretty conservative here. Single plug I had 12 initial and 28 total (added 16) and pulled it out after that. I'm not familiar with the MSD but you likely have more than 18 total dialed in, the factory had 26 total dialed in with the stock distributor. Maybe 12+18 for 30 total before it falls off?
Regarding timing, I'm actually pretty conservative here. Single plug I had 12 initial and 28 total (added 16) and pulled it out after that. I'm not familiar with the MSD but you likely have more than 18 total dialed in, the factory had 26 total dialed in with the stock distributor. Maybe 12+18 for 30 total before it falls off?
11-07-2010, 11:37 PM
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Stock for my '87 is 2 degrees ATDC at idle. Mechanical advance alone moves it to 26 degrees @4000 rpm. Add the additional 12 degrees static timing I've dialed in at idle and that puts it at 38 degrees @ 4000. The MSD Boost retard begins to take the timing off (I have it set to retard 2 degrees for each .1 bar after the onset of .2 bar of boost is reached). So by .8 bar boost all the 12 extra degrees advance has been removed....which puts me back to 26. Of course, don't forget that we also get something like 8 to 10 degrees retard at the distributor in reaction to the boost signal (dual pot distributor), so at maximum boost an un-modified timing curve has your full-on boost timing sitting around 16 to 18....which is about where mine should be 'cause all the extra 12 degrees has been removed by then and she'll be back to stock timing settings. That's just pencil and paper; would have to put her on a dyno to really find out.
For me, the extra 12 degrees really wakes up this low compression engine in the low to mid range. The key is to make sure I'm not seeing that extra timing when on full boost (although a little extra is probably ok). Make sense?
Oh....glad you've got her back on the road! I think I've got maybe another couple weeks here before we start seeing potential white stuff falling, so must get out a few more times before putting her to bed for the winter.
For me, the extra 12 degrees really wakes up this low compression engine in the low to mid range. The key is to make sure I'm not seeing that extra timing when on full boost (although a little extra is probably ok). Make sense?
Oh....glad you've got her back on the road! I think I've got maybe another couple weeks here before we start seeing potential white stuff falling, so must get out a few more times before putting her to bed for the winter.
