Time to say goodbye to the freakishly fast GP GT....
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From: Holt, MI & Lima, OH

Got the engine all done. Drove the car up to MI and parked it due to the flexplate. I didn't have my PCM so I had no */C belt on the car this whole time. I get the car up to MI and I drive my STE around for a few days. Then I take the GT and drive it to Pontiac Nationals to change the flexplate there. The flexplate breaks completely 200 ft. before the entrance and we push the car into the track. For a 200 mile trip I can't really complain that it broke in the last 200ft. We pull the engine on Friday and get the flexplate all out. We were waiting on Flexplate bolts but ended up reusing the old ones with locktite and we put the engine back in with the new flexplate. We flashed the PCM, got a belt for the supecharger and did wiring for the boost bypass valve and changed the oil and filled it with coolant then took it out for a test drive.
Pulled out and the car was strong. The boost gauge on the DIC lit up only 4 bars most of the time and occasionally blips of 5 bars. I figured the low boost was probably due to the cam and such and if we dropped the pulley it would go up. We scanned it and everything looked great and no KR. At this point I have missed all of the time trials and bracket racing for Friday and Saturday. So on Sunday morning I pull the 3.8 pulley off and press on my MPS hub. I put a 3.4 pulley on it that I borrowed from someone with 3 bolts that I got from Rogue (THANKS AGAIN!!!). Took it out for a drive and it still gets the same amount of boost. I unplugged the BBV and it still had the same amount of boost. So I got in the staging lanes for the only time trial run for Sunday and borrowed some tape from someone and took the vacuum line off the BBV and taped it closed. I made the pass and it got WAY more boost and had no KR and everything else looked good but the car misfired very badly all the way down the track, and with a bunch of other weight in the car it pulled me to a 14.66 @ 92 mph.
I bring the car back to the pits. Pull all the crap out of the car like my toolbox and all that (about 300lbs. worth of stuff), and then I close the gap down on the plugs. They were all at a little over .050" and I dropped them down to .044. Took the car for a test drive and it ran WAYYY better. I had no idea what to dial so I put a 13.30 on my window. Ran the first round and pulled off a 13.503 @ 100.05 with a 1.91 60'. This was nowhere near close enough to win the first round obviously but I wasn't expecting too.
All in all I'm very happy with the car. With no tuning on what was realistically its first pass on boost, it pulled off a 13.50. I was babying it off the line since I have a GT tranny so its not an HD, so I have a lot more potential with the launch as well. With tuning, a launch, and better conditions I see no reason why this car can't pull off high 12'*. But either way, I can't complain about a 13.50 since my PB before this was a 14.63.
I have pics but I'm not sure where my camera is right now so I'll post them later.
Pulled out and the car was strong. The boost gauge on the DIC lit up only 4 bars most of the time and occasionally blips of 5 bars. I figured the low boost was probably due to the cam and such and if we dropped the pulley it would go up. We scanned it and everything looked great and no KR. At this point I have missed all of the time trials and bracket racing for Friday and Saturday. So on Sunday morning I pull the 3.8 pulley off and press on my MPS hub. I put a 3.4 pulley on it that I borrowed from someone with 3 bolts that I got from Rogue (THANKS AGAIN!!!). Took it out for a drive and it still gets the same amount of boost. I unplugged the BBV and it still had the same amount of boost. So I got in the staging lanes for the only time trial run for Sunday and borrowed some tape from someone and took the vacuum line off the BBV and taped it closed. I made the pass and it got WAY more boost and had no KR and everything else looked good but the car misfired very badly all the way down the track, and with a bunch of other weight in the car it pulled me to a 14.66 @ 92 mph.
I bring the car back to the pits. Pull all the crap out of the car like my toolbox and all that (about 300lbs. worth of stuff), and then I close the gap down on the plugs. They were all at a little over .050" and I dropped them down to .044. Took the car for a test drive and it ran WAYYY better. I had no idea what to dial so I put a 13.30 on my window. Ran the first round and pulled off a 13.503 @ 100.05 with a 1.91 60'. This was nowhere near close enough to win the first round obviously but I wasn't expecting too.
All in all I'm very happy with the car. With no tuning on what was realistically its first pass on boost, it pulled off a 13.50. I was babying it off the line since I have a GT tranny so its not an HD, so I have a lot more potential with the launch as well. With tuning, a launch, and better conditions I see no reason why this car can't pull off high 12'*. But either way, I can't complain about a 13.50 since my PB before this was a 14.63.
I have pics but I'm not sure where my camera is right now so I'll post them later.
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Shawn... That car is going to be Hell fast once you get all of the tuning done...lol
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Way to go, man! It'* funny how we tell people that it'* really hard to supercharge an N/A car, until you went out and built this SOB with next to no effort. You seem like a natural mechanic with a good understanding of these cars. I hope you hit 12s with that thing!
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From: Holt, MI & Lima, OH

Originally Posted by big_news_1
Way to go, man! It'* funny how we tell people that it'* really hard to supercharge an N/A car, until you went out and built this SOB with next to no effort. You seem like a natural mechanic with a good understanding of these cars. I hope you hit 12s with that thing!
I'm going to attempt to do some minor tuning later this week and hopefully with better conditions and actually trying to launch it I'll do better. I might pull my interior too, I'm not sure. But I should be going to Norwalk on Friday for the T&T.
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Originally Posted by big_news_1
So just to be clear, you have the L36 crank, rods and pistons, topped off with the L67 heads, LIM, and M90?
From what I remember in the past the internals of the L36 are reliable to 300 Hp... Any guestimates on what kind of numbers you will pull down?
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Thread Starter
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From: Holt, MI & Lima, OH

Originally Posted by big_news_1
So just to be clear, you have the L36 crank, rods and pistons, topped off with the L67 heads, LIM, and M90?
Also what Boost are you running ans being a 9.4 : 1 engine where does that leave the static compression with the given amount of boost you currently have... As well what boost level are you looking for?
From what I remember in the past the internals of the L36 are reliable to 300 Hp... Any guestimates on what kind of numbers you will pull down?
From what I remember in the past the internals of the L36 are reliable to 300 Hp... Any guestimates on what kind of numbers you will pull down?
I am not sure on exact boost levels. I would guess its around 8-9psi but I don't know. I haven't had a chance to hook up a boost gauge to it yet. Next time I go up to MI I'll hook my boost gauge up. Like I said, the car has plenty of power how it is, and it pretty much has all I want to get out of it. I'd like to tune it and finish my exhaust, but other than that I'm done. I have no reason to try and push this setup, this is my DD it needs to be somewhat reliable. It gets out of its own way now so I'm happy with it. If I figure with 9psi boost, my effective compression ratio is 15.15:1.
I'm still trying to figure out exactly where i put my camera. Once I find it I'll post pics.
Shawn


