So ive got a slight problem here...

my set-up is

stock gsr turbo AFI Street turbo kit 57trim 12psi on E85...

im not too good at explaning my self but ill do my best...

my best time on these slicks 25X8.7X13 M&H on Lenzos is

12.155@113.68mph with a 1.71 60ft <---- on stock gsr turbo @10psi..
12.845@115.79 <----same night on street tires

that was last weekend when i was on 10psi...today we turned it up to 12psi because i wanted a 11 sec pass!! So i go out there today and i could not do any better than a 12.287@113.XX...And its not like i suck at driving...ive got more than 400+ passes...but only about 20-30 on slicks.. i was still cutting the same 60ft times and i was hitting the shifts perfect... so after i did about 4 passes of the same Facking times i decided to throw the street tires back on because i know my car on street tires better than i do on slicks...

So my first Street tire pass was a 13.07@116.89 mph with a 2.18 60ft..then my next pass was a 12.675@118.45 2.109 60ft <----best yet on street tires (prior was a 12.755@115.67)

I have not dynoed the car yet on 12psi but i am guessing it is around 330-340whp judging by the trap speed and the weight of my car with me in it which is roughly 2750lbs....

So i guess my question is are these slicks too big for my power level?? and has anyone ever encountered a loss of trap speed like i have tonight?? It seems like most people i know run 24.5X8.5X13..since my friend lent me these slicks i cant complain...

Any info or advice would help!! thanks



Modified by gringotegra at 2:45 AM 6/15/2008

 

Your 60 went down because it hooked which takes some wheel speed out of it. That is why your mph was lower.

 

yes, your results are typical

would you rather have a quicker ET with a lower MPH or a slower ET with a higher MPH ?

i pick the quicker ET

the more traction you get the more efficiently our car is getting down the track and in most cases the lower the MPH may be -- the more your tires spin the high MPH you will generally achieve but not necessarily any quicker ET

also consider your street tires are probably a smaller diameter than the 25" slicks you are running so that could have an effect on the MPH as well

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innes &raquo;</TD></TR><TR><TD CLASS="quote">yes, your results are typical

would you rather have a quicker ET with a lower MPH or a slower ET with a higher MPH ?

i pick the quicker ET

the more traction you get the more efficiently our car is getting down the track and in most cases the lower the MPH may be -- the more your tires spin the high MPH you will generally achieve but not necessarily any quicker ET

also consider your street tires are probably a smaller diameter than the 25" slicks you are running so that could have an effect on the MPH as well</TD></TR></TABLE>


very true, unless you are just putting down gobs of power. which in this case for your setup, the M&H 23s is probably your best bet. i didnt see you list a tranny or final drive, but simply based on the setup and power level i would say 24.5s would probably be too big. 22s would be too small.

my gsr tranny liked the 23s cause i wasnt at 10k goin thru the traps.

i just switched from the 24.5 to the 25 and picked up 5mph, and dropped .3 in the 1/8th and .33 in the 1/4

i would get those off asap, or retune and crank up the power!

 

Thanks for the info guys....

Just for info i have a GSR transmission so 4.4 final drive..

I would take the quicker ET over the MPH... but one of the things that i dont understand is how i traped the same with more power... ie. last weekend i trapped 115mph on the street tires and last night i trapped 118.45..yet with the slicks on both weekends i trapped 113.....maybe the slicks are not putting my car in its optimal power band..

i think i am going to see if i can try someones 23in or possibaly some 24.5 just because i expect to be at that power level later on...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gringotegra &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the info guys....

Just for info i have a GSR transmission so 4.4 final drive..

I would take the quicker ET over the MPH... but one of the things that i dont understand is how i traped the same with more power... ie. last weekend i trapped 115mph on the street tires and last night i trapped 118.45..yet with the slicks on both weekends i trapped 113.....maybe the slicks are not putting my car in its optimal power band..

i think i am going to see if i can try someones 23in or possibaly some 24.5 just because i expect to be at that power level later on...</TD></TR></TABLE>


because the car is hooking up and starting to make power from a lower point. for example if it hooks and the rpms drop to say 4500, instead of it spinning and staying at 6500+, where do you make more power@ 4500 or 6500+

you will see more accurate results with proper tire size, right now the size is too large and your results are slightly skewed, kinda like if you went out there on some 20inch slicks and said "man why is my ET so crappy, im on slicks" cause you would be outta gear and spinning to the 1/8th mile

 

yeah man i totally understand!!! thanks!!! time to find new slicks!

 

tire pressure?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by red02s2k &raquo;</TD></TR><TR><TD CLASS="quote">tire pressure?</TD></TR></TABLE>

tire pressure was at 8psi...

 

you can raise up your tire pressure to speed up your top end

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by red02s2k &raquo;</TD></TR><TR><TD CLASS="quote">you can raise up your tire pressure to speed up your top end</TD></TR></TABLE>

yeah thats true... but i think im just going to get some different slicks...or atleast try out some different ones...these are too big like other guys have said..

 

that is true good luck

 

thanks man...i just wanna run an 11 sec pass!!! hahaha i know the car has it in it...i just need to get the right setup..