Made it out to the track on Saturday for test n tune. It was partly sunny and cool. Beautiful day for racing. Anyway, it was the first time I had run my FD. Of 5 passes, my best was a 10.83 @ 130.3 with a 1.57 60'. On 93 pump gas and AI and 100% stock ports. The car was bogging off the line. Some runs worse than others. I know I have a couple of things working against me when it comes to the short time. I'm running a t56 with a 2.66 1st. And I'm using the Exedy twin disc clutch which uses a lightened flywheel. This is a street car before a track car so I don't really want to install a drag clutch. Since the t56 has a .5 overdrive, I think I would benefit greatly both on the track and street by switching to a 4.56 gear. I could leave with less bog and 6th gear would be usable under 80mph lol. I'm open to any suggestions. Thanks

 

There is no 4.56 available for the FD unless you have done the 8.8 diff swap. The closest thing will be a 4.44 out of the RX8 bolts right on. 10.8 on only 5 passes is awesome congrats. Clutch should be just fine don't worry about that.

 

Thanks for the compliment. Yes, in fact it has an 8.8 now. After I munched the torsen last fall, I decided to replace the entire drive line last winter. I'm also using a launch control that I built using a line lock and custom orifice. I have the orifice at .015". But it is still to big to slip the clutch enough to overcome the bog. I ordered a fine adjustable hydraulic needle valve to replace the orifice. I'd like to get a good run in with no bog to see exactly how well the 4.10 gears will perform before I go and make a change. I hope the weather will hold out long enough.

 

Great times for such a street-able set-up.

Seems like you are barely using 4th since it should be 116mph in 3rd with current set-up at 8,000rpm. I bet 4.56 rear will really help as it brings 3rd down to 104mph and still allows for trapping at 136mph in 4th (again at 8,000rpm).

Gear Ratio Speed Calculator

 

On the10.83 pass I shifted at 7500. Went through the cones slightly under 7k.

 

Damn, so you are trapping like 128mph?

edot- nvm. I see the 130mph trap now in the first post. So you have more in it when you get the 60ft cleared up!

 

 

Hell of a pass! Was that on street tires?

 

No, that was on M/T 26x10x15 drag slicks. Even with the 50/50 weight distribution of the FD, I think it would be very difficult to get a sub 2 second 60' on street tires unless of course your were referring to drag radials.

 

Been a long time since I posted an update. Still running an 8374iwg and 100% stock ports. Fuel is fatter than oprah. I strongly believe the 9 second barrier is possible just in the tune.

 

Congrats, what have you done since you last ran it?

 

Thats great!

 

I went from a 4.10 to 4.56 gear. Installed a turbo smart wg can and all 3 springs to hold higher boost up top. It seemed to flatten out after 7500 with the stock wg. Now it pulls hard past 8k. Added 2 degrees to the map and a few other small changes.

 

Nice 👍
How much boost were you running?
What rpm at 1/4?
I have 2.66 first with 4.4 rear i don't like that 1st gear on the street much on 26" tires. I should have gone 4.56 also. Still didn't hit the track with the new setup. Im running spec twin metallic pad clutch.

 

I hit 26 lbs of boost. Turbosmart canister with all 3 springs, no boost controller, straight off the canister. I was planning on turning it up but people kept oiling down the track. I only got in the 1 pass. The turbo really wakes up past 25. Roughly 8000 at the finish but I wasn't paying close attention. I have the close ratio t56. Mine is 2.66 also. The 4.56 seems just right. It really helps overcome that tall 1st gear and can actually use 6th gear at 70 mph. With the 4.10 I had to be going 80+.
I am running the Exedy twin disc. I figured out a way to incorporate it with the t56. I have to agree with Howard Coleman, it is a fantastic clutch and very streetable.