Centri and 3.91

[CHRI55]

looking into building my l99
Currently
Gpi ss4 nfc
3800 yank pa converter
Currently installing 3.91 and full rear suspension from bmr (all adjustable



Plan on going 418 then centri...

Anyone ran centri and 3.91 or 3.91 and a stroker

Any advice will help.. don't know how long before I boost it and don't want to pull the converter unless I really got to

Will eventually go zl1 ds, diff, axles and maybe 6l90

[BiggFoot]

I hate that there have been a lot of lookers but no one has responded to your question.

I ran 4.11 gears on a maggie maxed out with meth injection, etc., pushing 800 hp through a manual. Honestly, first gear was fairly useless on the street and when I switched to the big Procharger, we went with 3.70 gears as power was increased to 1000 hp on the car. Even with the 3.70 gears I am right at redline in 4th gear at the traps with a speed of ~ 143-144 mph so I sort of wish I was running 350 ish gears.

Now I am considering going with a built LSX so I can let the F-1X stop loafing and earn its pay. When the car is up around 1300 hp I dont think the 3.70 gears are going to be a good fit but I dont know yet.

In the end, its all about what YOU want my friend. I wish there was a silver bullet but I have found that trial and error is the way it goe$$$

[CHRI55]

Originally Posted by BiggFoot

I hate that there have been a lot of lookers but no one has responded to your question.

I ran 4.11 gears on a maggie maxed out with meth injection, etc., pushing 800 hp through a manual. Honestly, first gear was fairly useless on the street and when I switched to the big Procharger, we went with 3.70 gears as power was increased to 1000 hp on the car. Even with the 3.70 gears I am right at redline in 4th gear at the traps with a speed of ~ 143-144 mph so I sort of wish I was running 350 ish gears.

Now I am considering going with a built LSX so I can let the F-1X stop loafing and earn its pay. When the car is up around 1300 hp I dont think the 3.70 gears are going to be a good fit but I dont know yet.

In the end, its all about what YOU want my friend. I wish there was a silver bullet but I have found that trial and error is the way it goe$$$

Ikr lol.. but yea.. I race it on the street but its not a DEDICATED race car.. ion really car about the trap n all that.. long as it fast Idc... BUT.. I do want it to hook.. hopefully all this suspension, a slick and prep can fix that lol

[Greenhornet2]

If you want it to hook on the street with boost leave the gears alone. I can get good reaction in 2nd, not really in 1st but i only have road course tires. I think i'll hook decently with the drags i have.

[Bildo]

I went back down to like 3.45s from 3.71s and its still worthless with a F1-A and 427

[BiggFoot]

Originally Posted by Bildo

I went back down to like 3.45s from 3.71s and its still worthless with a F1-A and 427

Hmmm

[CamaroCracka]

I have a cammed 416 and it spins a bit if I don't rev the engine and just leave normally then floor it. If I wind it up at all, it just burns the tires and jumps to the rev limit before I shift to 2nd. I run 315s with a 300 treadwear rating. It might be pushing 500 whp on a good day, so I can't imagine getting any traction down low on the street with a blower.

The turbo car will smoke them at 30-40 mph coming into boost and again shifting to 2nd. but that is with 323s. I'm sure the track will be quite a bit different as traction is much better.

[eLeSthree]

I think it all depends on how much power you make. If its NA and needs help, up the gear. If its 1000+ whp, 3.91s are too aggressive. Unless of course you are at the track with good prep, have a good tire, and aftermarket axles/rear and suspension to handle it.

I know a guy with a 15 1LE that has made 1100ish and went to a 3:45 from his 3.91.

I have the stock 3.45 and struggle for traction on the street with a 305/45/18 MT R. How ever if i had 15s and a zl1 rear i might try the 3.73s to keep the rpms up.

So many variables, which is why i didnt comment before.

[racesloth]

I stuck with my 3.45's. Would like to go 3.91's but then it becomes more of drag only car. Traction is limited on street tires.

[hillshooter]

I make over 1000 Wheel and have cut a 1.45 on the street(dragy). I run a 3.73 gear. I have ran 3.23 for an entire season and the car is 1/10th or more faster in the 60' with the 3.73

People that blame traction on gearing have other issues they need to work out.

3.91 for a centri is going to be perfect.

[Taylortoons]

My car was setup for the street and I had 3.91 gears with a Centri. Was super happy with her manners on rolling starts.

[Greenhornet2]

Originally Posted by hillshooter

I make over 1000 Wheel and have cut a 1.45 on the street(dragy). I run a 3.73 gear. I have ran 3.23 for an entire season and the car is 1/10th or more faster in the 60' with the 3.73

People that blame traction on gearing have other issues they need to work out.

3.91 for a centri is going to be perfect.

Lol yea, that they want to drive the car on the street.

[BiggFoot]

Originally Posted by CHRI55

looking into building my l99
Currently
Gpi ss4 nfc
3800 yank pa converter
Currently installing 3.91 and full rear suspension from bmr (all adjustable



Plan on going 418 then centri...

Anyone ran centri and 3.91 or 3.91 and a stroker

Any advice will help.. don't know how long before I boost it and don't want to pull the converter unless I really got to

Will eventually go zl1 ds, diff, axles and maybe 6l90

Is that the BMR Drag Suspension you are installing? If so, it's quite a set up. I am running that on my car. Couple that with some Lakewood 90/10's and she will hunker down when you give it the juice.

[CHRI55]

Originally Posted by BiggFoot

Is that the BMR Drag Suspension you are installing? If so, it's quite a set up. I am running that on my car. Couple that with some Lakewood 90/10's and she will hunker down when you give it the juice.

I don't have the full drag kit with the coil overs and all. But I went the step under that. I do have the drag sway bar tho