The Juggernaut

iTrader: (7)

Okay,I just stepped up from a Hoosier QTP to an ET Drag.
Actual sizes- Hoosier-26.1x8.0 , ET Drag 27.3x8.6(both on 15" rim.)
I used to trap with the hoosiers @6100 in 4th gear (4.10 in a Moser)
With the ET Drags I trap at 5700 in 4th gear.

My car goes in Sept. 9th for k-member/A-arms
and a spool and gear.

Here's my Question- Do I go with 4.30's or 4.56's.?
I only need to make up 400 rpm's, will a 4.56 be too much?

The car lauched hard and consistant on the ET drags.(low to mid 1.6x's)
6k is what it liked the best.
I also need to screw the tires to the rims(they moved about 4"-5")

BTW-I was pulling the wheel off the ground.(So they tell me) <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Bob Cosby

Not an expert, but I'm sure full of opinions, one of which says "don't fear the gear!" <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I know your car is essentially a bolt-on setup, so I have an idea of the power band. What gear is then going to depend upon where your rpm limit is. I'm a big fan of putting the car 'on the limiter' through the traps, using the theory that you'll ET better by gearing the car to go as quick as possible through the 1st half of the track, and letting the second half take care of itself.

Not knowing your rev limiter, but assuming you can go beyond the factory 6200, I ran a few numbers...

4.56 w/27.3" tire = 109 mph @ 6100 rpm, and 116 mph @ 6500 rpm.

4.30 w/27.3" tire = 115 mph @ 6100 rpm, and 123 mph @ 6500 rpm.

So long as you don't mind trapping at ~6500 rpm, I'd get the tall gear.

Good luck with whatever you chose.
Bob

The Juggernaut

iTrader: (7)

Thank you,Bob!
That's exactly the answer I was looking for.
4.30 gears look perfect.When I step up to a cam I may go 4.56.

Could you do me a favor and check the calculation for
a 27.3" on a 4.10@5700 to see(and double check)my math.

Thanks
Sean

Bob Cosby

5700 rpm with 4.10's and a 27.3" tire gets 113 mph per the calculator. Not sure if that is what you are after or not. No matter, you can play with it for yourself at http://www.camaroz28.com/calcs/index.shtml. Click on the 'RPM and MPH Calculation' link near the bottom.

And dude....tubular K-member, a-arms, spool, and more gear...slow the hell down - I'll never get close to ya at this rate! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Honestly, I'd be doing similar stuff (Tubular front pieces, long tube headers, aftermarket mass-air meter, and a few other things), if I wasn't running in a class that requires all that junk to be stock (shorty headers ok). Also, I haven't run on slicks in a long time. I intend to at the MMRA race, and will be hoping for some high 1.5's (I go low-mid 1.6 on BFG DR's). My goal this fall is 11.6's....though I'd be lying if I didn't admit that the 11.56 that both Raughhammer and Rageman ran are both on my radar screen. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Good luck to you.
Bob

The Juggernaut

iTrader: (7)

Did I tell ya about the pin on hood I'm getting? <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Bob, your car is quick enough,just keep racing that class. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

RAGEman's record will be toast shortly.
Then the cam only record(11.50),That will be the easy one.
The quickest 346 M6 is 10.94?Then I'll work on that one.
Then comes the bottle. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Bob Cosby

Your car have the stock cam?

The Juggernaut

iTrader: (7)

My motor hasn't been touched.
When I beat the bolt-on record,I'll put a cam in. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Bob Cosby

Ah, gotcha. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Pro Stock John

iTrader: (34)

Bob, how about a Formula that makes peak HP at 6300, on 28x10.5x15 Hoosier slicks with a 4.10? assuming a 4000 or a 4600 stall, sounds to me like the car would work better on a 4.30 or a 4.56 as well. At what point is a car overgeared and running thru the gears too fast?

JS

iTrader: (4)

John I went to the website on CamaroZ28 and punched in my formula,I was suprised to find that my car would do better with a 26/4.10 than the 4.56/28 peaking at 6500?

It blew me away,I know now to run 4.10/26.It looks to be perfect for 123MPH and thats exactly what I'm hoping for come the fall.

I always thought my car was shifting into 2nd too fast and this data confirms it for me.Now all I need is the TP4400 back in the car and I'm ready for the fall.

I'd go and punch in your data and see what your car wants for gear/tire.

JS

<small>[ August 25, 2002, 10:08 PM: Message edited by: JS ]</small>

Pro Stock John

iTrader: (34)

I'm guessing I could squeeze a 4.30 gear in but no more from an effieciency standpoint. Joel with your smaller mill I'd think a bigger gear would be good since you need to buzz your motor higher, maybe you had too short of a tire (28x9x15 ET Drag=27.3) coupled with too loose of a converter and spent only like 600 rpms in each gear.

JS

iTrader: (4)

Just the opposite John,My converter was too tight and was dropping my shifts too far outta my sweet spot,Coupled with the larger tire this made matters worse..

I'm dropping over 1400rpm in tween shifts.I want to get my extension at 1100 MAX n betwen shifts and the NEW TP4500 will do that perfectly...

The car was shifting outta first too fast with the 4.56's,I like the way the car feels with the 26/4.10 and according to my PEAK (6500) this is the perfect tire/gear for 123 MPH...

Will see if I'm right John...
JS

Terry Burger

iTrader: (4)

Next set of gears I buy will probably be 4.30s with the 26" tire.

Pro Stock John

iTrader: (34)

Sounds JS like you needed to address the converter first since shift extension was the bigger issue.

Bob Cosby

John....A4's with small converters are a whole different ball of wax, and one I'm not familier with. That said, assuming a peak of 6300 rpm, I'd want it to run through the traps at ~7000 rpm.

Bob

Linear Velocity

iTrader: (1)

4.30's will be installed shortly on my car, I have 26" tires too, I'll let you guys know the results

JS

iTrader: (4)

John sorry I dont agree,6 outta the 10 quickest N/A 346 H/C cars run 26/4.10 combo's on the board.

Thats good enough for me....
I agree the converter is hurting me but not much more than a tenth....

JS

Pro Stock John

iTrader: (34)

Joel, if you asked the high 10 second 26" tire guys I bet you would find that their traction abilities are not a given... If they follow some big tire cars they are golden... If the track is a bit slick I bet the 10.8/10.9 guys are going 11.0-11.2 on 1.6's...

My point was with the 4.56 and the 27.3 ET Drags you ran, you might have been overgeared. But then you responded by saying your converter had poor shift extension which is a separate issue.

I have poor shift extension as well, mine drops to 4500 on shifts...