I have a 5 speed with the 4.10s. Anybody install the 4.30 gears and then go to the track and how much lower was your times? trap speed higher too?

Or anyone have an estimate on how much they could lower my ETs?

I have 24.9" Hoosier drag radials. I'm down to 11.28 @ 122.3 (19psi) and would love to get a 10.9x, without spending thousands on a single turbo, etc. I'm guessing I am at about 400 hp. I can't remember exactly but I think my rpms are at about 7k at the end of the track, so I should be good to keep it in 4th gear if the trap speeds increased a little with the 4.30 gears.

Best 60' times are 1.58 and 1.59.

So I'm wondering how much the lower gears would help. It's still a street car (although not driven very often) so I don't think I would want any gears lower than 4.3 or 4.33

Please let me know if anyone has any experiences at the track with gear changes, or an estimate. Thanks!

 

You're going the wrong way... you want to look into 3.90 gears.

 

Thanks for the post. Sorry but that doesn't make much sense to me, everything I know of says that a lower gear ratio (higher #) makes for better acceleration which is always good for drag racing, as long as you can keep traction. If you put bigger tires on, your car gets slower, smaller tires and your car gets faster and you get better ETs and trap speeds. should be like the same for the gear changes.

I forgot to mention my experience with different size drag radials which closely relates to gearing. The first set of drag radials I tried was MT ET street radials, 26x10.5x16. When I put these on, my car got slower!, because the tires are an inch taller than the factory size, we all know that larger rear tires generally make your car slower right. I was getting similar ETs (only because I was able to get better traction, launches and 60ft times) and my trap speeds were much slower because the taller tire changed the gearing to equal 3.70s, my trap speeds were like 5mph slower than what I was doing with my 265/35-18 street tires, not to mention the 18" rims are much heavier than the sotck 16s. So I had to get rid of the 26" tires, so I got the 24.9" 225/50-16 hoosiers which were also not as wide as the 26" MTs, and my trap speeds were back up to what they used to be. I also started getting better 60ft times with the smaller tires even though they were not as wide, because they made the gearing lower, and get good traction.

So if I got the 4.30 gears, I'm thinking my car will be able to accelerate faster in 3rd and especially 4th gear, I will be able to rev out 4th gear longer, so I think they could improve my trap speeds which would improve my ETs, just like the smaller tires compared to the 26" tires.

If I get the 4.30s, and need more traction, then I could just get the 26" tires again which are wider and could provide better traction with more hp in the future. 26" tires and 4.30 gears is basically the same gearing as stock with stock size tires.

Anyone agree with me? or have any experiences with the gearing? thanks.

 

WRONG. This is complete bullshit. Dont listen to this guy. A 3.90 gear is a HIGHER gear then a 4.30. This will slow your acceleration down and incease your top speed. The exact opposite of what you want to do.

 

Right. But a 3.90 gear will NOT increase your top speed at a drag strip, because it would slow your acceleration and not allow you to reach the top speed before the end of the track, the 3.90 will only increase your top speed on a highway, and it will take longer to get to that top speed.

A lower gear ratio (4.30) will allow you to reach your current trap speed before the end of the 1/4 mile because you can accelerate faster, you get to the previous trap speed sooner, therefore you have more room before the end of the 1/4 mile to continue to accelerate and improve your trap speed. This is how it should be I think as long as you don't lose traction compared to the 4.10 gears.

 

Exactly I meant top speed as in TOTAL top speed, not trap speed.

 

You should take in consideration even a lower one like 4.7.......
I have it on my FD (the one I use for drag racing)

1993 FD Road Racing Car, ring and pinion 4.70
1993 FD Drag Racing Car ,ring and piniuon 4.77

 

What size tires? How much did they help when you switched to them? Thanks for your info. Would it be not too bad on the street?

 

I love my 4:30 gears but I don't think they are the best for drag racing. On the hwy, my 5th gear actually is usefull! But In my experience they make launching the car much more difficult and the trap speed really doesn't change much.

I talked to Dan (JigsawRX7) about this and he used to have 4:30 gears and ended up going back to 4:10's since it was faster for him.

 

Thanks for the info. Did you lower your ET at all with them? Why is it harder to launch the car, and what tires did you use?

I'm guessing 4.10s would be faster if you have a lot more hp and are running like 9's and don't get enough traction with 4.30s, too much acceleration so the tires would just spin too much.

 

I really didn't notice my ET's going down, but I was only running a 12.1 when I went to 4:30's. I stayed the exact same which was a little disappointing for me. With 4:10's, it seemed like I could put the power to the ground much easier.......With 4:30's, I can remember hooking up nicely and thinking it was going to be a good run and towards the end of 1st I started spinning and hitting rev limiter and would have to slam it into 2nd too early. This was with 18" BFG G-force drag radials.


Once I went to MT street ET's, I haven't had a problem with me spinning anymore as long as I get my tires at least 160 degrees. I'm guessing I don't have enough power and I may want to go back to the 4:10's once I'm putting down 600hp like Dan.

 

At the end of last year, with the stock 4.10 gears and 24.9" Hoosier drag radials, my best run was a 11.19 ET @ 123.80 with a 1.61 60 ft. 7.19 1/8th mile @ 97.13.

This year I got 4.77 gears and 26" MT ET Streets. With the taller tires, it makes my final drive ratio 4.57 (Its like having 24.9" tires with 4.57 gears in the rearend). I also added a roll bar that weighs 55 lbs, and I removed 170 lbs of stuff like everything out of the interior, ABS, the greddy catback and some other stuff. Before I removed the 170lbs, I was running 11.5s all year and my best was 11.40 last week. After I just removed the 170 lbs, my best is now 11.16 @ 122.25 with a 1.53 60ft! 7.12 1/8th @ 94.54.

So I think the 4.77 gears hurt my 1/4 mile times. My time to the 1/8 mile is .07 quicker, but my time from the 1/8th to the 1/4 mile time is actually slower by .04 secs, and I didn't beat my best trap speed which I got with the 4.10s. With the 4.77s, I now shift into 4th gear right before the 1/8 mile.

And I can also contribute the better 60ft times to mostly my driving, the 170lb weight loss and the tires with longer burnouts. Last year my best was a 1.57 60ft with the Hoosiers, and all year I didn't beat that (I matched it once) until this last week after I removed the 170lbs. I did a 1.56 and a 1.55 with the tires spinning some and had to shift into 2nd right before the 60 ft mark, and my last run I did a longer burnout and I noticed I got better traction and pulled a 1.53 60 ft and didn't need to shift until right after the 60ft. Today I did a 1.52 60 ft, but it wasn't as cold out today so I was running 11.2x's all day.

So now I am wondering if I should put the 4.10s back in. But then my gearing will be like 3.93 because of the bigger 26" MT ET streets, and that may hurt my times, also because the bigger tires are 4 lbs heavier than the little hoosiers I had last year. It sucks cause I spent so much money on the 4.77s with all new bearings and the install and they didn't help my times. It seems the 4.30 gears would maybe work best, then my final drive ratio would be like 4.12, which is like that same as last year when I got my best trap speed and that's when my car was 115 lbs heavier.

 

Where is your peak torque at? You may need to go with a 3.90 gear for "your" car.

 

On the dyno sheet, peak torque is 309 at 5600 rpms.

Torque is around 287 at 5000 rpms, 295 at 6000 rpms, and from there it is a steady drop down to 250 at 7000 rpms and 210 at 8000 rpms.

So for the most part, the torque is falling off right after I get into the next gear after switching gears around 8000 rpms. The HP is still up around 320 around 8200 rpms

I'm thinking about going back to the stock gears.

 

Iwould stick with the stock gears 4.10

 

I think you will be better at your HP levels with the 26" tires and 4:30 gear ratio. You ran slower on the 26" because your lack of torque more than anything else.
The 4:30's should help with this issue.

When you start to make gobs of power, then you might think about lowering the gear ratio or increasing tire size again. Since fitting a taller tire is hard to do on these cars without chopping it up, the consensus is to lower the gear ration (numerically). You find that high hp cars, run lower gear ratio due to having a lot of HP for one (duh) which cause them to run out of gear on the track and is less violent too for the increased available power.

Whats your sixty foot right now with the 225/50-16 Hoosers?

 

Ya I think I will either put the 4.10s back in, or I bet I would get best results with 4.30s so I'll have to buy them.

Best 60ft with the Hoosiers and 4.10s was 1.57. Then I got the MT ET streets and 4.77 gears at the same time, all year best 60ft was again 1.57 (but more consistent lower 60 fts maybe from better driving), then the past couple weeks I started getting better 60 fts, alot of 1.53 - 1.55, and my best is a 1.52

 

Keep the stock 4.10's. You will get more mph and they are stronger. Spend your $500 elsewhere!!
BTW. My best 60' is a 1.41 with the 4.10's, but they don't do anything for your 60', just so ya know, lol..

 

+1

 

Best hooking 10inch tire fd3s I've ever seen is Ari from rx7.com. call them up and see what they say. They have more than enough experience to make you feel more comfortable in your decision. I have 4:30's and plan to go lower before getting re-tuned. More power, lower gear ratio.

 

The best hooking rx7's on IRS that I know of are hooking 1.30's and lower!

 

now thats hooking. Want my car to hook like that one day

 

I will probably put the 4.10s back in soon, I know I will run faster down most of the track with the 4.10s and the 60ft shouldn't be much slower. I wish I would have got the 4.30s instead of the 4.77s, or not switched gears at all, would have saved me about $1500 with labor and new bearings/seals.

My gears make a very loud annoying howling noise since the 4.77s where put in, definitely alot louder than it should be, and it wasn't like that before with the stock 4.10s, I'm guessing the guy that put them in didn't do a perfect job.

 

back from the dead.... So why is Ari runninmg the 4.30's or did he swap back? I understand the idea of once you make over a certain amount of power you want a lower gear (3.90-4.10) But Ari was making a ton of hp and if I am not mistaken ran a 4.30? Just curious as I have a 4.44 ring set sitting in the garage. Someone school me please!

 

I think your going to get alot of diffrent opinions depending on to many variables!

H/P torque,weight, tires, suspension, trannie, and problly alot more will make the diff gearing much diffrent from one car to another.

For me so far going 430 gears raised my 60' increased my trap speed!
It did seem to give me more consistency.
I think i will need to get more aggresive with my first half to see any benifet from the 430 gears.

Thats all i have seen.