Will an FD's rear end handle 420whp from a high rpm launch on Drag radials

 

yes but not well

 

you should be okay...

 

You'll be ok if you can shift mad quick.

 

something will break, the differential and axles are first in line....

don't believe me? try for yourself and let us know the outcome.

 

Its not really about your power. Its how wide/sticky your tires are and if your clutch will hold. If nothing slips something will break at that power level. Youre not going to launch very well with a stock rear end anyways. I say rear end meaning everything back there.

 

I just had an over one hour conversation with Ari about all this (9 second rx7.com FD).

What kind of clutch do you have? sprung or unsprung 6 puck, and your driveline is going to suffer.

Ari recommended that I run Mickey Thompson ET Street wrinkle walls in 26x10.5x15 to help cushion the drivetrain.

I also am running a diff brace/re toe links and trailing arms/rp diff bushings/cryoed TII diff/cryoed axles/cryoed PPF in hopes of no breakage. It's kinda funny, my car isnt even really a drag car, lol.

 

i broke mine with 368 rwhp shifting in to 2nd in the 8th mile with a spec 4 puck clutch and diff brace and solid diff mounts re toe links and triling arms with es 100 245 45 16 on stock rims i would recomend upgrading i put a kaaz 1.5 way in and i love it

 

I have a a street/strip clutch with 412 rwhp...I haven't launched hard on drag radials yet but on street tires it seems to hold up just fine...Going on 2 years of abuse now. Doubt it would be holding up to the abuse with stickier tires tho.

 

Honestly dave, for the street you cant beat that setup. I really miss my old ACT HD-00 (which incidentally uses an OEM disc). I will tell ya that for any kind of launching/drag race duty that sucker won't cut it. Of course, I have had this clutch for over 2 years now and I have yet to launch on it

 

Your diff will be the first to go.... why do I know? Because it happened to my car and mine only puts out around 330-350 HP somewhere around there... I think my diff was getting old though.... hehehe.

 

It depends how badly the car was abused in its life. If you are the second or third owner then I would be worried about my rear end. I blew mine up when I had 322rwhp. I then invested in the kazz rear end and have loved it since then. If I were you I would be careful. I would also start saving for a new rear end. Hopefully you will get luck and just blow up the diff and no the pumpkin like I did. My buddy on the other hand wasn't so luck and he pretty much blew a huge hole in the pumpkin making the cost of a new rear end go up.

R.K.

 

Is you Kazz klunky when turning at slow speeds?...Like parking lot speeds...I was driving with jason Manley (I think that's his name) GoodFella's old roomie and his was loud as ****...I thought something was wrong with it when I first hear it.

 

speaking from experience i destroyed my diff with 3XX hp first hard launch on (stock twins)
wheel hop kills rears

 

Iam getting the excedy cluth and flywheel put on, i dont know my dyno numbers yet but they should be around there on 91 gas

 

What are good quarter mile time with 420rwhp, theres a guy thats getting the new cobra wants to race my car for a 1,000bucks, all he wants is drag radials and he thinks he will win, i started laughing and he didnt know why, he doesnt know about a little thing called power to wight ratio, that new cobra weighs like 3900pounds with 475hp

 

Which one? Exedy makes several different clutches for the FD, and other posters are indicating that the type of clutch (puck? sprung?) can affect your driveline reliability.

-Max

 

ooo i see thanks

 

Ya it clunks a little bit when you are turning slow especially in parking lots. I got used to it and now it doesn't bother me anymore.

R.K.

 

Dont be so cocky, your car is not "the ****" and dont stress mine is worse. Im getting the feeling you need to slow down. Youre diving into a shallow pool and youre gonna bust your head at this rate. If he puts on slicks hes going to tear you a new ******* right off the line. Youre going to be playing catchup without any doubt. None. Youd definitely beat his trap but Ill be real surprised if you have the best ET.

 

Being has the car isn't even in the show rooms yet you'll have plenty of time to practice at the track.

 

As Ari said soft sidewalls are the trick and should save the diff for anything under 500hp. M&H's are street legal and accomplish what the MT's do. I've never used drag radials so I don't know how soft the sidewalls are on them. It basically acts as a big damper, but also stores the energy as well.

I don't quite follow if you're saying he'll be on drag radials and you'll be on normal street tires? If so you'll lose badly unless he's a chump driver. If you're both on drag tires then you should be okay provided you're a good driver and have plenty of practice. The reason I got such great ET's is because I had LOTS of practice. Hundreds of quarter mile runs. The Brooks example is ideal. He hadn't been drag racing much when I went down there to drive his and Pettits car. I ran something like .7 seconds better than him in his own car on the same day. He improved a lot as time went on. Don't go out thinking you're Johnny Hotrod because you can do burnouts in the parking lot or race people from a roll on the highway.

 

I ran the stock rear when I was making 561rwhp last November and it was fine. I ran it again when I made 643rwhp, although not making a full pass, it held fine for the launch and thats where it would break. As said prior, if you run a slick, the sidewall will give which will help the stress of your rear, axles, etc..

 

My diff took a dump on me. Totally stock drivetrain....lower 400's whp. I got another stock one. Seems to be working fine.

 

Jason manley is artguy, he was a customer of ours at the shop with a black FD, M2 bb twins. My old roomie with the SCC car was Jason Cameron.

When the Kaaz is installed you can reverse some of the clutch packs so it is not at full lockup and it won't clunk as much.