systalis

I'm building a 350 for my '92 rs that I am planing to run N2O on. The internals will be all forged and built for running nitrous on. My friend that is helping me says that I should run 4.11's in the rear.

The engine alone should push 425hp at the crank and will be a weekend warrior only. Are 4.11's to low to run nitrous on the street without frying the tires? I want to run drag radials on a 16x8 rim and think that 3.73's would be better, but he insists that 4.11's would be faster.

I plan on running a 100 shot or so and my goal is to have the car run at least one 11 second pass, but it will rarely be run at the track. The engine will be carbed with a NX plate system. The car only sees about 30 miles a week, will have a built 700r4, and fuel economy is the last of my concerns, I just want the car to be able to hook on the street. Are 4.11's too low?

87IROC350

I wouldn't run anything lower than 3.73's with a 700r4.

systalis

With nitrous or just in general? The tranny will be built by a professional builder to handle 600hp.

87IROC350

In general the first gear is so low already on a 700r4 and depending on the intake/cam combo you will have traction problems and/or run out of gear on the top end before you hit the 1/4. Is it carb/TPI/TBI?

Sonix

iTrader: (1)

That's right, the 700R4 has one of the steepest 1st gears around, with 3.73 gears it's lower then your friends 4.11 with a TH350 (if that's the comparison to be made).

Choosing the "right" gears for your quarter mile means you want to go through the traps in top gear (or in your case, 3rd gear), just as you go over peak HP. So if you went with 4.11's you'd want a tall tire generally.

Did I give you my spreadsheet to help calculate that? It's not for 1/4 mile, but helpful none the less...

I'd do 3.73's, that way it's not a bear on the highway...

What, what rear end are you going to use with 11 second passes, 425FWHP and nitrous?

systalis

I know I'm gonna get riped on for this, but I'm using the 10 bolt thats on the car now but its gonna be rebuilt with stronger parts that he has in his shop including a set of currie axles. If the rear blows, then it blows and I'll buy a 12 bolt or 9 inch or something, but I know a few people that run low 12's on the stock 10 bolt so I should be OK as long as I don't constantly beat the snot out of it.

brodyscamaro

IMO, you'll want more shot later on down the road; especially if you know your engine can withstand it. I'd go with 3.73s...

systalis

I just found out why he insists on 4.11's. He has a set he'll give me for free!! If I want to go 3.73's, he says thats cool but I'll have to buy them.....The 4.11's are worth a try. If I don't like them I'll buy a set of 3.73's throw them in and not have to worry about wasted money. Personally, I think that I'll probably get the 3.73's eventually or maybe even 3.5x but for free... I gotta try the 4.11's. Thanks for all the info guys. When I get it running in about two weeks I'll let y'all Know how she hooks.

Toby

1991CamaroRslow

iTrader: (3)

If you're going carbuerated I don't see any reason not to try the 4.11's. Get decently sticky tires but avoid very hard hooking drag slicks. 4.11's have so many teeth on that tiny 7.5 ring gear that there's hardly any meat to them so there's a good chance you'll strip the gear set but for free, why not. Just be logical with the nitrous use, don't spray immediatly from a dig. That's the wonder of nitrous you can activate and turn it off at will.

systalis

Yeah, thats kinda what I was thinking too. Like I said, if its too much gear, I'll just spring for a set of 3.73's or eaven a set of 3.5x's or something.

I won't be spraying it all the time but I'm building the engine to take it anyway!

gray89vert

iTrader: (3)

3.73's if you go with 4.11 your first gear will be useless...it will run out of gear so fast you wont beleive it

WheelsUp84z

iTrader: (2)

i have 4.10's and a 700r4, i deffinately run out of gear at the top end, so im forced to run all motor 1/4 miles and nitrous 1/8 miles and the first gear is worthless on spray 3.73 or 3.55 is what i going with, oh it prob doesnt help i have 26" tires either

brodyscamaro

I'm fixing to be running 4.10s on the bottle with a 4L60E. You bet your *** I'll be sprayin 1st gear...

LB9GTA

iTrader: (1)

I have 3.73's with a 700R4 and I spray out of the hole with a 125hp shot.
I also have a 26 inch tire. A 28 inch tire would be better for me.

systalis

The engine is brand new and going in the car in two weeks. I won't run the nitrous until I'm sure the thing is broken in correctly. I will probably run the 4.11's until I install the nitrous and then spring for the 3.73's.

It's hard to pass up free gears when you have crappy stock 2.73's. Maybe I'll try to trade the 4.11's for 3.73's.

1991CamaroRslow

iTrader: (3)

If you can find someone to trade that would be a great idea, I would be after 3.42's or 3.55's personally.

systalis

Would you be after the 3.55's if you didn't plan on using the nitrous often? I don't plan on taking the car to the track very often. The only time I will eaven use the nitrous is when i want to give a beefed up stang or a stock vette a run for their money. Most of my play runs will be made on engine only, thats why I would opt for the 3.73's. Am I making a mistake?

1991CamaroRslow

iTrader: (3)

3.73's will be a good choice (and WAY easier to find). It's always best to tune the car for off nitrous performacne as opposed to on nitrous performance because you'll only use the nitrous maybe 1/1000ths of the time you drive the car.

systalis

Yeah, that sounds like a plan.

Thanks for all the info guys