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Time to say goodbye to the freakishly fast GP GT....

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Old Aug 2, 2006 | 02:33 AM
  #11  
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With as many 3800s as his family has, it'* equivalent to having a zipper on the motor. Way to go, Shawn! Looking forward to seeing what this sucker can do.
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Old Aug 7, 2006 | 02:38 PM
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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.
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Old Aug 7, 2006 | 08:28 PM
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Thats awesome great job and keep us posted
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Old Aug 7, 2006 | 11:28 PM
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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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Old Aug 8, 2006 | 03:33 AM
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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!
Realistically it would be a PITA to do if we didn't have people like Ed Morad. But when you have Morad, you just go to his shop and pick up all the parts you need off of an L67 and then throw it on. Its really pretty simple.

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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Old Aug 8, 2006 | 08:57 PM
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So just to be clear, you have the L36 crank, rods and pistons, topped off with the L67 heads, LIM, and M90?
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Old Aug 9, 2006 | 01:04 AM
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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?
Yes. I have my completely stock and untouched 212k+ mile L36 block with L67 heads, LIM, blower, TB, and of course injectors, fuel rail, all the pulleys, the balancer, etc... I also put in an XP cam, 90lb. springs, retainers, & timing chain.

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?
The L36 bottom is VERY strong. Thats what a lot of the "big dogs" use because they make more power with it. When Zooomer dynoed his 410whp with his M90, that was on an L36 bottom. They are pretty strong. I have no idea what kind of whp the car is making right now, I'd guess around 260whp maybe??? If I saw 275whp out of this setup by the end of the year I would be happy. Thats all I really want to see out of it. It has PLENTY of power around town right now and I know with any more my tranny will really be pissed at me. So I'll just do some minor tuning, and get a 3" downpipe and a powerlog and after that I'll be done with it. Thats all I really plan on ever doing to it.

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
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Old Oct 13, 2006 | 01:58 AM
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Man its been a while!

Any updates? Hows the trans?
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