cabaynes

iTrader: (4)

Hey guys. well my next FD will more than likely be 20B powered...

anyway, the FD is such a great performer both in straight line performance, and around a track. The 20B has peaked my interest because of greater torque, and because of the lower hp/rotor ratio, rather than running all that stress on a 13B. Plus the sound is just great

Anyway, the only thing I'm really worried about is having issues with bumpsteer. I don't want to have a a car that is not as capable as a stock FD on the track. The weight ratio issue is nothing to worry about because I will not have all the accesories and I will be doing some relocation of things. But bumpsteer seems to be the only thing that hasn't been 100% worked out yet, and I don't want to do this conversion only to be dissapointed when I try and take the car out to the circuit and I can't push it like I could on a stock FD...

If anyone has any advice, experience, ect... please post up. I know that Howard Coleman was doing some research on the problem, but I haven't seen an update on that in a while. I was looking forward to his findings.

94RHDFD

iTrader: (3)

The bumpsteer question has been address'd there are a few ways out there to handle it, really depends on how your new subframe will be constuct'd

Red-Rx7

I have no bumpsteer.

cabaynes

iTrader: (4)

Well i was thinking about just ordering the subframe from Pettit. I understand that they no longer use the core of the stock subframe and now use a totaly custom piece? is that true? I have not heard whether their previous problems with bumpsteer have been corrected, and how they are now solving the problem with the spindles.

sorry guys but i've been out of the loop. trying to catch up, but i'm just confused about this stuff, and i dont want to call Pettit cause i'm sure they'd tell me that there is no bumpsteer just to sell it to me... before i take on the project i just want to have all my ducks in a row

cabaynes

iTrader: (4)

could you let me know what subframe and setup you have? just so i have an idea? thanks

felix_is_alive

i am about to post some pics on my thread regarding this i have just installed john's(20b 3rd gen) bumpsteer correction kit and i only have to allign and test the car to see if everything is working properly

cabaynes

iTrader: (4)

i'll be looking forward to those results

fi addict

this thread might be helpful. I have been saving for a while now and the pics are amazing and very thought provoking https://www.rx7club.com/showthread.p...o&pagenumber=1

Red-Rx7

I have the stock subframe. We didn't touch the steering rack. Hence no bump-steer.

fi addict

RED-RX7- i think you should bless us w/ a close-up of that.

94RHDFD

iTrader: (3)

Let me know how it works out with your subframe.

Red-Rx7

Here is an undershot:

jspecracer7

Whoa. Now my question is how much for a replica aluminum oil pan for the 20B with holes for the FD rear plate?

c00lduke

wouldn't the front cover of the 20b run into the rear of the steering rack?

Red-Rx7

Not if it is done correctly.

Red-Rx7

Not sure if it is for sale or not. You would have to call Acosta Racing. Besides, there is more too it than just that.

jspecracer7

I didn't want to go thru the hassle of making my own subframe. I can fabricate/tig & mig weld anything else that needs it, but the subframe to me just seems like such a b*tch. I can build a motor w/o any problems. What else is involved? I'm assuming that you will have to shorten the 20B LIM correct?

Herblenny

iTrader: (13)

Mike, I keep bringing these old thread about your 20b conversion.

I'm wanting to know how much the LIM need to be lowered.. also, any other pics of the oil pan?? I'm also guessing that pick up line must be relocated??

I'm definitely going toward your direction than going with modified subframe.

dlambert

its my car that howard and i will try to fix this winter to busy driveing it now to take it apart howard will post results in mid winter .my car has terrible bump steer other than that it would be hard to beat going straight .i dont track it so the problem is controllable on street.i street race when someone is doumb enough to try me it is perfect under these conditions.

Herblenny

iTrader: (13)

diambert,

I've met you at the Rotary Revolution this year. Have you thought about just getting a 20b subframe from Hinson or someone else and restalling the 20b?? I've heard Hinson collected the bumpsteer issue (not perfect, but better).

cabaynes

iTrader: (4)

I was under the impression from what I overheard Mr. Lambert saying at rotary revolution this year, that he was using a petit subframe with modified spindles? Someone correct me if i'm wrong.

I have heard about Hinson's products Phil, but I dont think their method is any better than Petit's when it comes to bumpsteer. Modifying the steering will sadly always result in some bumpsteer. we need to develop a subframe that allows you to keep everything else in tact, however i dont think thats really possible with the limited space and the 20b oil pan... (unless you do it like Red-RX7 with the 13b rear plate)

Herblenny

iTrader: (13)

Charlie,

That's acturally what I'm planning to do (like Red-RX7). I've figure out the intake manifold clearance issue and my engine needs to be rebuilt so, i'll be doing the 13brew rear plate and custom oil pan.. I was hoping Mike (Red-RX7) would take a pic from underside.. just to give me an idea on oil pan.. But I guess because of acosta, maybe he can't really show the bottom. who knows..