t-von

iTrader: (8)

Those are 13b components Heath. I'm unsure about the alternator.

94RHDFD

iTrader: (3)

If I,m not mistaken Cam uses the 13B components including PS, ALT, WP, that's what I did anyway. The car he had @ RR had all of them.

AdrenalifeRX7

Where do you get the kind of money saved up to do all this anyways?

FD from R1

bought some Yahoo stock in 1998 and sold in late 2000

sub9lulu

iTrader: (7)

wish i did that ......

RotorMotor

iTrader: (5)

thanks, yeah i couldnt really tell. it could be a 20b alternator with a smaller (less "thick") pully..... the 20b alt pulley is pretty substantial. i was wondering because i was trying to figure out what does and does not interchange between the 13b accessories and the 20b bolt holes

94RHDFD

iTrader: (3)

Most everything is interchangeable if you go with 13B components you just have to remove a couple mounting studs

bigmack000

looks good david cna't wait to see how it runs when it all together
joel

David Hayes

iTrader: (6)

Hi all,

Thanks for the posts. As for the 13B versus 20B components, I know that Pettit uses the 13B AC components and relocates them. Pettit does run new lines for this though. As for the power steering, I don't know but I think it's the stock unit (like 20B Third Gen states).

PheonixDownVII, good luck with the music career. When you make it, does this mean that you'll pay a way stupid rapper price for my car? If so, let's ink the deal now!

1point3liter

David,

I just came across your post. This is Bryan, I have the black 93 R1 that used to have a T78. I believe we met at the former speedcraft.

Anyways.. I'm looking forward to seeing your car when it's finished.

I've known a couple people in town with 3 rotor conversion (not preformed by pettit). One did have a pettit subframe. They had problems with bump steer which I don't think anyone has brought up yet. Have you driven cam's 3 rotor car?

Im sure you're anxious to have the car back. It's a great feeling to have your car back on the road after a big project.

FDNewbie

iTrader: (10)

Bryan, can you elaborate on what bump steer is? I remember reading about this before...and I think the PFS 3-Rotor initially had probs with this, but I believe Peter came up w/ a way to overcome that issue...but for the life of me, I can't remember what it was lol. It's on one of the plaques he has at the shop...(some article from a magazine).

Thanks
~Ramy

1point3liter

"The tendency of a vehicle to suddenly veer or swerve to one side when hitting a bump or dip in the road. The condition is caused by uneven toe changes that occur as a result of the steering linkage or rack not being parallel with the road surface. This causes the wheels to change toe unevenly as the suspension undergoes jounce and rebound. "

FDNewbie

iTrader: (10)

Thanks

1point3liter

Pettit’s subframe moves the steering rack forward and down. The spindles are also modified. The geometry of the steering is compromised and bump-steer is commonly experienced.

PF's method of evading bump-steer is to modify the firewall and sit the engine further back in the chassis so the stock steering geometry is retained.

jimlab

One minor correction. I think you meant to say "tie rod linkage not being parallel with the lower control arm".



If the linkage is not parallel to the lower control arm, it will travel through a different arc than the control arm. Hitting a bump causes uneven movement of the tie rod linkage in relation to the lower control arm, pulling the tire in or pushing it out (toe change), causing the car to veer in an erratic manner, "steering" without movement of the steering wheel. Hence the term "bump steer".

jimlab

One option that I looked into when I had a 20B was a dry sump oiling system like the 13G (below). However, the 13G is not a 20B, and the prices I was quoted by Mazdacomp for everything but the aluminum plate for the bottom of the engine (which would have had to be fabricated), was in the neighborhood of $3,000, IIRC. That was around the time that I decided that a lighter and shorter V8 was a better option.

1point3liter

Thanks Jim. I had a feeling you'd chime in.

So the problem could be corrected if one were to align the linkage parallel to the lower arms? I imagine pettit would do this if it's correctible.

Are there other factors that can cause bump steer such as the linkage being angle towards the front or rear of the car (even if it's parrellel with the lower control arm)?

It would be interesting to see a picture of the steering rack mounted on a 3 rotor subframe vs a stock FD or even my LS1 setup.

Is that your car previous to installing the tubular subframe?

HDP

iTrader: (2)

I'm so glad you posted this, because I basically had no idea what everyone meant by bump steer. Thanks!

1point3liter

I just took a pic of the steering linkage on my LS1 car.

Anyone have a 2 rotor and 3 rotor cars they care to show?

jimlab

Yep, that's what Pettit's modified steering knuckles are for, although I'm not a big fan of relying on something welded to cast iron where steering is concerned. Welding cast iron is difficult, and if not done correctly, can introduce stress cracks. I'm sure that Pettit has done it correctly, though. I have a picture of their modified spindles somewhere at home that I can try to find tonight.

The other alternative is a "bump steer elimination kit", which is what Hinson's LS1 kit uses (on the right in the picture below) and what Pettit used to use, I believe. Basically, spacers are used with a longer tie rod shaft to move the tie rod joint an equal distance from the steering knuckle to the distance the steering rack was lowered.



The issue with either of these two solutions is that with a smaller diameter wheel, you can run out of space. With the spacer option, however, you are giving the steering linkage more twisting leverage on the knuckle, so you want to keep the distance you move the tie rod end from the knuckle to a minimum.

Moving the steering rack forward or rearward on the same plane a reasonable amount does not adversely affect steering geometry. As long as the linkage is moving in the same arc as the lower control arm, you're fine. If you move the rack too far forward or backward, though, you eventually need a longer tie rod, and you may run into interference problems with the wheel or other suspension components.

Note that in the stock position (shown below), the steering rack sits behind the steering knuckles.



Yep, that's Grant's cradle. He didn't move the rack because he assured me that it could stay where it was... as long as you didn't mind knocking a big dent in your oil pan to clear the power steering fittings. I didn't have that option because of my stroker crank, and it was a half-assed solution anyway.

On my cradle we lowered it about 5/8" to get clearance for the fittings for those who wanted to keep the power steering, but I later found out that the Maval Gear converted manual rack eliminates the problem by eliminating those fittings altogether. I bought a bump steer elimination kit from Hinson to space the tie rod ends accordingly.

PhoenixDownVII

Hey, I won't be stupid, or a rapper, but I will give you more for the car if the money's there. See you in a couple years.

Red-Rx7

Another way of doing it is making a custom oil pan and LIM. My car doesn't have bumpsteer, and uses the factory 13b engine subframe.

Fatman0203

Im guessing the LIM has to be more tucked in? The the oil pan?

TwinTurbo'D

How much has this costed = up till now?

Red-Rx7

Tucked in? Chopped. There are a few other things that need to be done, but that is the basics of it.