does more power constitute different rear gear ratio?

[encasedmetal]

So I know that most suggest 4.10 gears at least with a centri setup- but I was wondering if you have more power do you want to change your gears accordingly? for instance a 450hp with 4.10 gear vs. a 800 hp car with 3.73 gears? or should the 800 hp car just stay with 4.10 gears- drag racing is not the objective here btw

 

[01yellercobra]

I think it'll also depend on your power band and traction. If your power band is still fairly high, then you won't want to step down on your gears. While you have power, you have to wait while you get into the power band. But then if you can't get traction, then steep gears will only make the problem worse.

FWIW, I'm running the stock 3.27's. I haven't drag raced in years so I'm pretty happy with them. But there are times I wish I had a little more gear to get things moving a little faster though.

 

[encasedmetal]

I just really have to wonder if with the step up ratio of the F1a and at 20+psi if 4.10 gears will be too much- especially road racing:banana:

 

[Jimmysidecarr]

I just really have to wonder if with the step up ratio of the F1a and at 20+psi if 4.10 gears will be too much- especially road racing:banana:

3.73s, 3.55s or 3.31s for road racing with over 500 RWHP.... IMHO.The more power then use slightly less gear.

You don't want to have to go to an over drive gear.

My T56 is one to one in fourth. At TWS CCW I hit about 140 just before turn one, I am pretty close to 6800 with 3.55s.

I don't know what power you will be at with 20 PSI, but I can tell you with a fair amount of confidence, that it WILL over heat with much more that 15 PSI, unless you have NASCAR level cooling.

I would plan on less boost for the the open track stuff and use that 20 pound set up for the strip.

 

[TAF]

Rear tire height is also a factor.

 

[98 Saleen Cobra]

3.73s, 3.55s or 3.31s for road racing with over 500 RWHP.... IMHO.The more power then use slightly less gear.

You don't want to have to go to an over drive gear.

My T56 is one to one in fourth. At TWS CCW I hit about 140 just before turn one, I am pretty close to 6800 with 3.55s.

I don't know what power you will be at with 20 PSI, but I can tell you with a fair amount of confidence, that it WILL over heat with much more that 15 PSI, unless you have NASCAR level cooling.

I would plan on less boost for the the open track stuff and use that 20 pound set up for the strip.

^^ALL THIS!! plus here is my expierence.. I am currently running 4.10's with my 600rwhp setup.. it is entirely way to much gear.. I had 3.55's before and it was kind of a dog on the street so I wanted more umpf. but it is pointless and my car is actually slower lol. If I were to go to Thunderhill or laguna seca I'd probably have to hit 5th.. So right now I'm going to have 3.73's put in.. It seems like a perfect gear to me for both open tracking and street driving.. Also 20psi on a roadcoarse isn't going to happen bud.. Sorry. Just like Jimmy said you will overheat, if not worse do damage to your new motor.. You don't need HP to go fast, you need seat time and expierence, then suspension, then hp.. More HP equals more things to go wrong trust me. You won't be able to get traction for the most part with more than 650rwhp on a track anyhow.. Unless you have a full road racing suspension setup like a full Griggs or MM and some seriously sticky tires it's not going to happen lol. :beer:

 

[crazycarlo]

yeah man I have 4.10's sitting in a rear but im trading a guy for 3.73's because i worried also man. I have friends that said with that much gear esp on street tires that 1st n 2nd gear were useless.

 

[Mr.Bolt-on]

Very good info in this thread. In my opinion, and from what I've seen. The more power you make, the less gear you need. 4.10's or more are for Drag Racers, or cars with less horsepower that can shoot out of curves faster on the road course. For bolt-on N/A midly modified 4.6 cobras... 4.10's are just fine.

Plus, the more gear you have, and how the transmission is geared will allow you to use 4.10's or higher on the street or road course. Hence the reason why you see Ferrari's using 4.30 gears, because they have 6 speeds geared for that ratio.

 

[encasedmetal]

3.73s, 3.55s or 3.31s for road racing with over 500 RWHP.... IMHO.The more power then use slightly less gear.

You don't want to have to go to an over drive gear.

My T56 is one to one in fourth. At TWS CCW I hit about 140 just before turn one, I am pretty close to 6800 with 3.55s.

I don't know what power you will be at with 20 PSI, but I can tell you with a fair amount of confidence, that it WILL over heat with much more that 15 PSI, unless you have NASCAR level cooling.

I would plan on less boost for the the open track stuff and use that 20 pound set up for the strip.

was waiting for you to show up- always respect your opinion btw. the biggest pulley I can run is a 4" blower pulley-with a f150 8rib pulley that nets around 18-20 psi I have seen (correct me if I'm wrong). so I can't really pulley down. I do have a ROn Davis radiator- and meth inj.- with intercooler setup- looking into getting my intercooler piping coated by Jet Hot-they say you can touch the piping and it feels cool after a pull after you have it coated. I do understand about the overkill of power on roadcourses-just kinda happened this way. anyways- but I guess the general consencus is 3.73's - anybody have a certain preference on differentials while I'm in there?

 

[98 Saleen Cobra]

Damn that's crazy.. You might want to try to set to a smaller crank pulley from Innovators west or something to bring the boost down even more if possible. As for differentials, Torsen T2R and don't look back.. The only issue with the T2R is that you don't want to drag race or do launching with it.. Another good option is a Eaton Posi unit.. Those are great as well. I've had both in my car.

 

[encasedmetal]

I just talked to procharger and they said that I should at most only run a 4.25" pulley with just an 8 rib setup. I will have to clearance my alternator to run this pulley. So looks like I will be able to get down to 15psi after all;-) I am seriously going to have to scrap together some cheese to get a dedicated bracket so I run way more boost if I want-no more bracket flex then-but also no more powerpipe- so don't know if I want to buy one to begin with?

 

[98 Saleen Cobra]

I just talked to procharger and they said that I should at most only run a 4.25" pulley with just an 8 rib setup. I will have to clearance my alternator to run this pulley. So looks like I will be able to get down to 15psi after all;-) I am seriously going to have to scrap together some cheese to get a dedicated bracket so I run way more boost if I want-no more bracket flex then-but also no more powerpipe- so don't know if I want to buy one to begin with?

Damn that seems like a huge hassle lol.. I would just get a vortech setup for real. The brackets are awesome, and they are proven on the track as well. I talked with John Griggs for a long time about prochargers on the track. He didn't recommend them due to seal issues, that's why he chose vortech on his car. He also uses Paxton as well, which is owned by vortech. Anyways I would get a Vortech and be done with it.. Go A/A with a T trim or a JT-trim and you'll be golden. :beer:. But if you already have an F1 then doing all that might be the way to go. Also I would highly recommend running a powerpipe if you are open tracking. You don't want a piece of rubber get through that screen and mess stuff up..

 

[encasedmetal]

Damn that seems like a huge hassle lol.. I would just get a vortech setup for real. The brackets are awesome, and they are proven on the track as well. I talked with John Griggs for a long time about prochargers on the track. He didn't recommend them due to seal issues, that's why he chose vortech on his car. He also uses Paxton as well, which is owned by vortech. Anyways I would get a Vortech and be done with it.. Go A/A with a T trim or a JT-trim and you'll be golden. :beer:. But if you already have an F1 then doing all that might be the way to go. Also I would highly recommend running a powerpipe if you are open tracking. You don't want a piece of rubber get through that screen and mess stuff up..

I already have the f1a-picked it up last weekend for a song-I bought the entire intercooled kit (polished) with 8 rib setup for less than I sold my unintercooled 96-98 kb setup for. now it's just odds and ends. I think I am going to see how far I can go with the 8 rib setup power wise- saw a guy recently hit 792rwhp with a similar setup to mine and a 8 rib (procharger said they've never seen more than 640 rwhp on an 8 rib setup(typical manufacturer BS I gather). I would like to have the powerpipe as I talked to Anderson already and they were more than helpful- and I feel that having the blower so close to the radiator would be a restriction when using the renegade bracket system

 

[98 Saleen Cobra]

I already have the f1a-picked it up last weekend for a song-I bought the entire intercooled kit (polished) with 8 rib setup for less than I sold my unintercooled 96-98 kb setup for. now it's just odds and ends. I think I am going to see how far I can go with the 8 rib setup power wise- saw a guy recently hit 792rwhp with a similar setup to mine and a 8 rib (procharger said they've never seen more than 640 rwhp on an 8 rib setup(typical manufacturer BS I gather). I would like to have the powerpipe as I talked to Anderson already and they were more than helpful- and I feel that having the blower so close to the radiator would be a restriction when using the renegade bracket system

Oh damn I see. Is the renegade bracket different than the regular bracket?? I'm not to sure.. I'm sure that you can make a custom pipe some how.. Jeez 792 that's just crazy lol..

 

[jcveron]

still a gearing question but kind of different route. im VERY new to gearing tech. if you have a car set up like evil03 (2.8LC KB, cams, built engine) and maybe a small shot (50-75) and say putting down a bit over 800 to the wheels on race gas, what would the ideal gearing be for mostly street but some strip use? would like 9s but i doubt my driving thus far will net me that plus im keeping the t-56. looking for jimmys suggestions. they are always spot on :beer:

 

[98 Saleen Cobra]

still a gearing question but kind of different route. im VERY new to gearing tech. if you have a car set up like evil03 (2.8LC KB, cams, built engine) and maybe a small shot (50-75) and say putting down a bit over 800 to the wheels on race gas, what would the ideal gearing be for mostly street but some strip use? would like 9s but i doubt my driving thus far will net me that plus im keeping the t-56. looking for jimmys suggestions. they are always spot on :beer:

IF you are looking at nines man I would keep the 3.55's and run a 28'' tall tire. You're going to be trapping around or over 140mph.. I know I'm not Jimmy but I'm pretty knowledgeable.

 

[jcveron]

i was told by a couple people to go with 3.73's but then again i am seeing the 3.27's from above and was wondering about those. i would like to have some traction below third gear. and thank you for the suggestion i am open to all. just figured jimmy would put in his two cents as well lol

 

[encasedmetal]

here's a link to the renegade/dedicated bracket I'm talking about-
House of Boost: Corvette parts, Z06 parts, Camaro parts, GTO parts, G8 parts, Trailblazer SS parts, LS1 parts, LS2 parts, LS3 parts, LS6 parts, LS7 parts, LS9 parts, LSX parts, Mustang parts - 4v Ford Mustang Dedicated Bracket System

 

[98 Saleen Cobra]

i was told by a couple people to go with 3.73's but then again i am seeing the 3.27's from above and was wondering about those. i would like to have some traction below third gear. and thank you for the suggestion i am open to all. just figured jimmy would put in his two cents as well lol

Yea with 3.73's and a 28'' tall tire you will be trapping at a higher RPM which would be good, as long as you aren't out of your powerband.. So I thank that you should be good..

here's a link to the renegade/dedicated bracket I'm talking about-
House of Boost: Corvette parts, Z06 parts, Camaro parts, GTO parts, G8 parts, Trailblazer SS parts, LS1 parts, LS2 parts, LS3 parts, LS6 parts, LS7 parts, LS9 parts, LSX parts, Mustang parts - 4v Ford Mustang Dedicated Bracket System

Damn that thing is sick!! but like you said it lacks the pipe that I highly recommend.. But that damn 1100 bucks!!! that's not cheap by anymeans..

 

[encasedmetal]

Yea with 3.73's and a 28'' tall tire you will be trapping at a higher RPM which would be good, as long as you aren't out of your powerband.. So I thank that you should be good..



Damn that thing is sick!! but like you said it lacks the pipe that I highly recommend.. But that damn 1100 bucks!!! that's not cheap by anymeans..

I've also seen pics of cobras with the headunit mounted on the drivers' side- who makes that bracket?