I would not go 4.30 gears with close to 400hp.
If hp was really close to stock.. then 4.30's are nice.

The more power the more gear u need to put the power down.
The ideal gearing is to have a looong first gear and the rest short.
BUti think making first gear shorter will hurt ur launch and 60'

 

so sounds like a 4.30 gear or area is the way to go "if" you can get a longer 1st gear? I noticed turbotommy just ran a 9.6 trap around 149 and has a very long 1st gear..

 

I put my stock 4.10s back in recently, they are much better than 4.77s. I thought about putting 4.30s in but didnt want to take the chance of wasting my money again and it runs real good with the stock gears. My best run shown below was with the 4.10s.

 

Turbotommy has a 20b and more tQ hes able to get away with that.
If we had trannies that you could really shift the 430 gears would be the **** but there is little diffrence between 410/430...2 teeth .
I think a trannie would be great for you next, expensive but you could drop et more with a good trannie.

 

I know busted.. Trust me. A auto conversion and solid rear have been on my mind so long. Then I could go bracket race in the 9's...LOL...../

 

I just decided to try the 4.30 gears for a few reasons. I just bought a rear end from a auto rx8 with the 4.30 gears that are the same and work for the FD, i got in on ebay for only $279 shipped. I have to take apart my rear end cause it makes a somewhat loud constant annoying noise that only varies with speed,and I am thinking it might be the pinion bearings cause the pinion did not spin smoothly, it had a notchy feeling. I recently put in a fc differential and I noticed this then, but I never removed the pinion to inspect the bearings. So since i got a good deal on this I will also use the bearings. I have bigger tires so I really dont think these gears will hurt me at the track and I know they will make it better for street driving with non sequential turbos.

 

Let us know the results. Are you changing anything else this time?

 

lol, well I did just put in a newly rebuilt engine with a mild streetport. So I will be able to tell you how it feels on the street but any better results at the track and we wont know for sure how much the gears will help since I have not raced it with the new rebuilt engine yet. I just cant wait to get rid of the annoying noise and might as well throw in the new gears now.

 

so that rx8 rear end I got actually has 4.44 gears in it and I dont think those would be as good for drag racing for my car, I would rather try 4.30s or keep the 4.10s and use the pinion bearings from the rx8 rear end which feel very nice and not bad like the bearings currently in my rx7. So now am looking to find some good used 4.30 gears and sell these 4.44 gears in good condition. If I cant find some 4.30s for a good price then I will just stick with the 4.10s but wanted to try 4.30 cause my slicks are 26" and for street driving cause I am non sequential with 18" tires with bigger 25.3" diameter.

 

I'm putting my rear end back together with the 4.10s, couldn't find a used set of 4.30s and didn't want to spend alot on new gears, and I will be using the pinion bearings from the rx8 rear end. My rx7 pinion bearings make alot more noise I can hear just from spinning them with my hands (out of the diff. housing), compared to the rx8 bearings, especially the outside smaller pinion bearing, so the guy that put those 4.77s in and new bearings must have overtightened the pinion nut or something. I wanted those 4.30s mostly for street driving with non seq. twins but I know the 4.10s are very good for my car in the 1.4 mile so I'll stick with them, and get my money back by selling the rx8 parts, and I will be able to tell a more accurate difference between my last motor and my new rebuilt motor by not changing gears at the same time.

 

In all honesty, going to 4.30 from 4.10s wont do much for thier cost, they will also surely not get you into the 10s. You need to look elsewhere.