Guest bojo68 Posted August 2, 2007 Share Posted August 2, 2007 wigenOut-S30,Here is some data on boost threshold for my setup: Flooring it at 2500 rpm 2500 = 4psi 2600 = 5psi 2700 = 6psi 2800 = 7.5psi 2900 = 8psi 3000 = 9psi 3100 = 10psi The wastegate was set to 10 psi. I think you would have to wait until 3500 rpm to see 15 psi. These numbers would probably improve with an EBC. The response between shifts is very quick if you're shifting where the next gear leaves you above 3500 (and I would think you would be when driving hard). The power builds in a nice linear fashion and lets me hammer each gear after 1st without cooking the tires too bad. More is better, but this is nice currently since I'm operating inside of what the tires can handle (215/60/14). The Mega Log Viewer lets you put in your drive train ratios to display MPH. I logged a full effort blast through the gears and found the following: 0-60 mph = ~5 sec. (the tail end of second gear) 0-100 mph = ~ 12 sec. (the beginning of fourth) I'd like to see those times lower and I think there is a little more to squeeze out of this setup yet. Congratulations! If you got that far, your good enough to get the rest of the way pretty easy. Nice work! Before I got to the end of the posts I was expecting catastrophe when I saw the flat out @2500 test come up. Ya did good. Do you have any temp/pressure monitoring going on? Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 3, 2007 Share Posted August 3, 2007 Yes, mine and big-phils were at 20psi before detonation took over...mine would have been fine I believe, but had problem with edis causing timing not to change....Which I had no clue of till afterwards. 20 pounds; wow. That's essentially the max you'll run on pump gas. The stock N42 innards can withstand that? I was told like 250 crank hp max (which I'd roughly guess was 10 psi). I though the pistons required replacement at 250 and rods needed attention (or replacement) about 50 hp upward of that... Mark Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 3, 2007 Share Posted August 3, 2007 I was expecting catastrophe when I saw the flat out @2500 test come up. Why? If the car has proper ignition tuning at high load and low rpm this shouldn't be a problem... I'm sure these guys figured out that timing slowly tapers in for the first 2500 +/- 500 rpms at high load. Mark Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted August 3, 2007 Share Posted August 3, 2007 Several people make 350+hp with stock pistons and rods... read some of the turbo na post and post on how much boost pistons will take...detonation is usually the limiting factor.Also read up on differences in na and turbo motors...they both have the same compression if later models and the pistons are cast only with differences in where the ring lands are cut. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 5, 2007 Share Posted August 5, 2007 Several people make 350+hp with stock pistons and rods... read some of the turbo na post and post on how much boost pistons will take...detonation is usually the limiting factor.Also read up on differences in na and turbo motors...they both have the same compression if later models and the pistons are cast only with differences in where the ring lands are cut. Hmm, thank you I will indeed search some more. The dude that sold me the Z (on here) really had some incorrect information. Quote Link to comment Share on other sites More sharing options...
nish Posted August 9, 2007 Author Share Posted August 9, 2007 Well, something didn't like the punishment too much. I've developed a problem with the number one cylinder. It still runs strong, just 5 1/2 cylinders strong though. Still only boosting to 10 PSI. I saw some excess blow by coming out of the VC breather one day and decided to do a compression check. #1 = 120 psi (dry and wet) #2 - 6 = 165 psi dry Next, since I don't have a leak down tester, I put a compressed air nozzle with a rubber seal in the plug hole at TDC. The air was easily exiting out of the oil fill hole in the VC. When I covered the VC the air came out the PVC breather. It was then I fully realized I was screwed. I'm not sure why the compressed air comes out of the VC at TDC so easily. All I can figure is the head gasket has a breach to the oil orifice. That, and I feel pretty certain #1 piston is screwed. Perhaps there was a preexisting weakness on the 120k mile org. block. The plan is to run this setup into the ground until winter. Maybe with one last 16 PSI huzzah to put it to bed proper. Then I'll tear it down and build back up with a p90 and forged pistons. I've searched around and found some info on forged pistons, but nothing conclusive. I'd gladly accept any suggestions on what to get for a low price. I'm hoping to use the 280 rods / p90 head / flat top pistions / and 8.0 to 8.3 compression. Everyone who gets a ride fears for their life. And I'm the only one who thinks it needs to be faster. Adam Quote Link to comment Share on other sites More sharing options...
oinojo Posted August 9, 2007 Share Posted August 9, 2007 Well, something didn't like the punishment too much. I've developed a problem with the number one cylinder. It still runs strong, just 5 1/2 cylinders strong though. Still only boosting to 10 PSI. I saw some excess blow by coming out of the VC breather one day and decided to do a compression check. #1 = 120 psi (dry and wet) #2 - 6 = 165 psi dry Next, since I don't have a leak down tester, I put a compressed air nozzle with a rubber seal in the plug hole at TDC. The air was easily exiting out of the oil fill hole in the VC. When I covered the VC the air came out the PVC breather. It was then I fully realized I was screwed. I'm not sure why the compressed air comes out of the VC at TDC so easily. All I can figure is the head gasket has a breach to the oil orifice. That, and I feel pretty certain #1 piston is screwed. Perhaps there was a preexisting weakness on the 120k mile org. block. The plan is to run this setup into the ground until winter. Maybe will one last 16 PSI huzzah to put it to bed proper. Then I'll tear it down and build back up with a p90 and forged pistons. I've searched around and found some info on forged pistons, but nothing conclusive. I'd gladly accept any suggestions on what to get for a low price. I'm hoping to use the 280 rods / p90 head / flat top pistions / and 8.0 to 8.3 compression. Everyone who gets a ride fears for their life. And I think I'm the only one who thinks it needs to be faster. Adam try adjusting the valve lash on that #1 cylinder. Then do another compression test. I saw a video from this forum that had # 2 and 5 i believe down at 125 while the rest was like 160. After the valve lash everything was back to normal. Quote Link to comment Share on other sites More sharing options...
datman Posted August 9, 2007 Share Posted August 9, 2007 Yep just rebuilt my l28..tested compression before fitting plugs and got 160 160 160 160 120 100 !!! adjusted all the valves to correct gap and got 170 on all of them, had me a little worried though. Quote Link to comment Share on other sites More sharing options...
JSM Posted August 11, 2007 Share Posted August 11, 2007 Everyone who gets a ride fears for their life. And I think I'm the only one who thinks it needs to be faster. Adam LOL! You should put that in your signature line. That was great! Quote Link to comment Share on other sites More sharing options...
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