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Discussion Starter #1
finally got some issues sorted out with the car. stock short block, hci, mp70. c4 w/ brake. fixed header leaks, learned how to launch and build boost off the line and car was was a whole new animal. the first pass was 12.15 @ 128mph. best before was 122mph. car spun hard out of hole with a 2.25 60 ft. lowered tire pressure frpm 14 to 11 and the next 3 passed i skrewed up one thing or another. in the pits i noticed my exhaust leak had returned but there was nothing i could do about it. i was able to make one last pass before leaving and turned out to be the best. went 10.9949 @ 124.64. what i dont understand is my mph slowed 4mph but my et was the fastest.

.5949
1.6591
4.5902
6.5952
7.0451
100.03
9.1800
113.95
10.9949
124.64


tell me what ya'll think and where i should go from here.
 

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What tires are you on? Suspension setup. IMO a 1.65 60' is ok but not stellar as far as other 10 second cars go. The E.T. is there for a .56-.58 60 FT IMO. Trap speed.. well welcome to the world of turbos.. Also what rear gear?
 

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Discussion Starter #3
275x60x15 bfg drag radials
50 50 lakewood rear shocks
100% stock 4cyl suspension
control arms bushings springs front struts all 4cyl stock.
3.27 gears.
pretty happy after seeing only 390 rwhp on the dyno through a c4. must be a little more than that i guess.
 

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Discussion Starter #8
hooked very hard leaving on 5 lbs of boost with 11 psi. at 14 psi they went up in instant smoke. bought these used and my next set will proablly be the same. very impressed. espically since my suspension is 100% stock 4cyl minus the rear 50 50's.
 

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Discussion Starter #10
nittos are more for street than strip. they worked with my auto a little but with the 5spd they sucked.
 

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Its an old racers rule of thumb that seems to work well.
It would be nice to have a formal explanation.

What was your eighth mile trap on the 128mph run?
That doesn't always ring true for turbo setups. Many such as myself notice the opposite. When your spinning your tires with a turbo, your loosing boost...thus loosing power.
 

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That doesn't always ring true for turbo setups. Many such as myself notice the opposite. When your spinning your tires with a turbo, your loosing boost...thus loosing power.
Correct, there's minimal load so the boost suffers - hence, mph suffers. At least this is the case with my car.
 

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hooked very hard leaving on 5 lbs of boost with 11 psi. at 14 psi they went up in instant smoke. bought these used and my next set will proablly be the same. very impressed. espically since my suspension is 100% stock 4cyl minus the rear 50 50's.
Ok. I'm going to lower the pressure on my MT's next time out. I had them set at 15psi and they spun.
 

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Discussion Starter #15
another thing i was told by a certin factory stock racer, "well known". he takes a set of new dragradials and puts 5 psi in them and drives about five miles and breaks them in. he claims it breaks down the sidewalls and helps them wrinkle like a slick. not sure if it works or not but this guy knows his sh**. cant hurt. seems to work for me.
 

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another thing i was told by a certin factory stock racer, "well known". he takes a set of new dragradials and puts 5 psi in them and drives about five miles and breaks them in. he claims it breaks down the sidewalls and helps them wrinkle like a slick. not sure if it works or not but this guy knows his sh**. cant hurt. seems to work for me.

I just use a slick :king:


Since I don't run a street tired class anymore I just swap out for my ET Drags 26-10-15 and set them at 12lbs.
 

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When I had my srt-4 my mph was always faster when I spun. I don't know the exact reason why, but that's just what happened. It was a fun car but 400+ hp and tq on a fwd vehicle sucks balls. Glad I have my coupe.

The side wall thing is true. Since your bfg's are a radial the sidewalls are very stiff. Driving on them with 5 psi stretches the side walls so they wont be so stiff. If you drive too fast the tire will expand and it wont stretch as much. Take turns veeerrryyy carefully.

If you're not ready to spend a lot on suspension you can make a small improvement by removing the front sway bar and install front springs with a higher rebound rate. Some drag struts for the rear wouldn't hurt either. Probably looking at 300 bucks if you shop around. Should see consistant 1.50, mid 1.40 60's if you can sort out how much boost you leave on. My cars a stick and I can get 1.40 60's with basic suspension mods on et streets with 11psi in them.
 

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Discussion Starter #19
i got 50 50 lakewoods on the back but thats it. this winter im going to box in my stock upper and lowers and install new bushings. try to leave on some more boost also. if i could get consistent low 1.5's i would be happy.
 

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That doesn't always ring true for turbo setups. Many such as myself notice the opposite. When your spinning your tires with a turbo, your loosing boost...thus loosing power.
this is correct - on forced induction the more wheel spin=you lose mph. the more the car hooks the more mph.:evilgrin:
 
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