Guys,

I was curious what MPH people were hitting on 24.5" slicks with a GSR tranny, and at what RPM they are at when they hit the finish line...

The reason I am asking, is that I used to run 26" slicks, and my MPH was 147, and I was pretty much at the top of 4th when I cross the finish line. But I am re-doing the car to be more like a SPFWD car. So I plan to run 24.5" slicks this year. Now, I know that with my new setup, I dont expect to hit 147MPH, but I am a bit concerned about where in the RPM range I will be if I am trapping maybe high 130's low 140's on a GSR tranny. (I REALLY dont want to have to shift into 5th)

Anybody have some insite into this?

 

we run the 24.5 slicks with GSR gearing

on our 155-157 mph passes we are going through the traps at 9500 rpm in 4th gear or so if i remember correctly from the datalogs

 

there is a gear speed calcualtor that you can enter your slick size and rev limit and it will tell you what the top speed is at the rev limit. I am looking for the link. I am sure dturbocivic will chime in with it shortly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MazworxRaceSupply &raquo;</TD></TR><TR><TD CLASS="quote">we run the 24.5 slicks with GSR gearing

on our 155-157 mph passes we are going through the traps at 9500 rpm in 4th gear or so if i remember correctly from the datalogs</TD></TR></TABLE>

thats good to hear... because I really dont spin the car much past 9k... so using your numbers, I should have plenty of headroom..

thanks james...

 

the gear speed calculator's will work to an extent, but arent exact. You will have to take into account for tire expansion.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by miller &raquo;</TD></TR><TR><TD CLASS="quote">the gear speed calculator's will work to an extent, but arent exact. You will have to take into account for tire expansion.</TD></TR></TABLE>

and wheel spin.

 

I am going 142 mph on a gsr trans with 24.5's crossing around 83-8500ish

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boner_Ben &raquo;</TD></TR><TR><TD CLASS="quote">I am going 142 mph on a gsr trans with 24.5's crossing around 83-8500ish</TD></TR></TABLE>

cool.. thanks, that makes me feel much better about it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boner_Ben &raquo;</TD></TR><TR><TD CLASS="quote">I am going 142 mph on a gsr trans with 24.5's crossing around 83-8500ish</TD></TR></TABLE>
what are you taking each gear to during the run?

 

about the calculators, also consider the trap speed is an average, the car is actually travelling a couple mph faster then the trap indicates.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MazworxRaceSupply &raquo;</TD></TR><TR><TD CLASS="quote">we run the 24.5 slicks with GSR gearing

on our 155-157 mph passes we are going through the traps at 9500 rpm in 4th gear or so if i remember correctly from the datalogs</TD></TR></TABLE>
That's weird cause i have a GSR tranny and at 150mph i am at 9600-9700rpm. Same tire too. Could be more growth i guess?

 

25inch slicks + gsr tranny + 4th gear+ 9200rpms = 149mph on a dynojet.

That''s what my car showed when we dynoed it at the Quakerstate dyno challende at the track.

Adriano

 

that souds corec twith 24.5 to me. cause when i was running 22s in was hitting 130 at the top of fourth at 8500. so 24.5 sould easily d 150 at 9k+ . i just got my new 24.5-9 but havent tried them yet & will be shifting at 9k now. just finishing up traction bars.
i was wondering this also so good wright up

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boner_Ben &raquo;</TD></TR><TR><TD CLASS="quote">I am going 142 mph on a gsr trans with 24.5's crossing around 83-8500ish</TD></TR></TABLE>


same here...
with 24.5 inch slicks

mines more like 8k

 

You also have the 8.7/25-13.

John
M&H