3:73's to 4:30s

stihl-066

New Member
Jan 4, 2006
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I have 3:73's in my car now. I mainly run it on an 1/8 mile track. It has a T5z in it for a tranny. I run an 8.4 now with a 1.9 60ft. Do you think switching to 4:30s will help me any.
 
I have 3:73's in my car now. I mainly run it on an 1/8 mile track. It has a T5z in it for a tranny. I run an 8.4 now with a 1.9 60ft. Do you think switching to 4:30s will help me any.

do you use slicks or at least drag radials? if not 4.30s probably won't help very much...but they would be more fun
 
I have no idea what rpm you cross the traps, you didn't list any info. No one can really say. I will say that it will help.

4.30's are perfectly streetable, fyi.
 
Gear it so youve run out a gear right as youre about to trap, dont gear it so you have to grab the next gear and cross the trap a second later, you're gonna cross it out of your peak power and youre gonna lose time shifting too.
 
I think it was Jrichker that posted a link the other day (it was a thread about fuel injectors). Anyway when I was browsing that site, they had a gear calculator. Maybe he will post here for you.
 
We need a little more info about the car. Whats it weigh? Engine combo: cam? heads? intake? Tire size? Frame connectors or suspension of any kind? Im not familiar with 1/8 mile times...what does a 8.40 equate to? Depending on these answers, there may be money better spent in other areas of the car that will net bigger gains than a gear change.
 
Look up a couple of posts and you will see my mods. Ok why is my signature with my mods not showing up on some of the posts. Ok there it worked. My 60ft times are not the best. I plan on putting on some sontrol arms this winter as well. Might even bump my cam up to a XE284-H-10 to get a little more top end out of it. Damn it my mods are still not showing up.
 
Oops sorry my bad...im still not used to how this signature thing works either. You sig only appears the first time you post in any thread and then it doesnt show up to save space and what not. I see your mods now. It seems like you have all the bases covered in terms of power, suspension, and electronics....so gears might be a good idea for you. I think it all depends on the end goals for the car...good luck man
 
My goals are to make it run faster in the 1/8 mile with what I have now.

Bottom-line, if youre crossing right at the end of a gear, don't increase the rear-gear because you're just going to force a shift that will cost you time and speed.

If you're trapping right at the end of your powerband already, you'd be better off either a) finding ways for a better launch and better traction or b) modifying the engine so the powerband extends further, so your car pulls HARDER at the end of its band and will rev higher and still make power. Just don't go too far.

I went too far on this cam and intake, expecting to build a forged high-cr bottomend in the future. Well it never happened, so now my powerband is skyhigh and I have to over-rev the motor to get it to trap decently...(see sig, you'll get what I mean)

Don't ignore suspension! Launch and first gear performance and traction factors BIG-TIME in your 1/8 mile performance.
 
Since your going for 1/8th mile performance, the 4.30's might not be a bad idea...and then again the 3.73's might stick you in a better powerband when you cross the line. I know my 3.73's with my h/c/i can get me at the very top of 3rd gear for me at about 6,000rpm. I usually make 4 shifts though before the 1/8th mile and still get 87.31mph.