RWD CONVERSION

[Guest spyhunter2k]

Here is how one person summarized what would be involved in the start of a RWD conversion:

"Strip the cars interior- gut the middle to make room for a driveshaft, and a transmission bell housing. You'll need to custom fab the rear end to have an axle and differential- so you'll need new rear suspension for this as well. You'll need to customize the motor mounts so it mounts the "proper" way, flywheel facing the back. You'll need to do just the opposite to the front wheels that you did to the rear. Strip the dif and axles, customize them to be normal non-powered wheels."

I am by no means promising that I will do this, but I have a couple of mechanic friends who seem convinced that they can help me accomplish this. I'd first like to try to sort out most of the issues involved and begin making a "build manual" of sorts. Even if I am not the first one to do it, I think it would be useful for the person who eventually does.

It would be broken down by steps and the details/comments for completing each one, like...

1. "Strip the cars interior- gut the middle to make room for a driveshaft, and a transmission bell housing."

First off, is there enough room for a bell housing and transmission tunnel to be added? I would think yes, since one of the prototype high-performance Reattae were a RWD version.

2. "You'll need to custom fab the rear end to have an axle and differential- so you'll need new rear suspension for this as well."

I'm almost positive that the article I have on the aforementioned RWD prototype said that Corvette rear suspension of a similar vintage was used. Could start there, and figure out how to attach/mofify as needed...

3. "You'll need to customize the motor mounts so it mounts the "proper" way, flywheel facing the back."

Wonder how hard this step would be...?

4. "You'll need to do just the opposite to the front wheels, that you did to the rear. Strip the dif and axles, customize them to be normal non-powered wheels."

I don't believe the article mentioned if the front suspension was also changed out for Corvette, but will look back...

[Vincent Vega]

This would be a very cool project. If you are willing to part with some of the electronics that make the Reatta unique it could be very worthwhile. Trying to keep the touchscreen for example could be a big hassle.

[Guest F14CRAZY]

I think the touch screen ECC could still be kept. What motor would you use? I'm thinking a turbo BUICK 3.8L <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[2seater]

Don't forget the steering, the rack is right where the bellhousng would be. Not impossible to be sure, but another headache. I always wondered about another fwd drivetrain added to the rear. I have heard of something like that with another brand of car with a single ECM running both engines. I have no clue how that would be done, but it would certainly be different.

[Guest spyhunter2k]

I am thinking of using a rebuilt stock engine with the s/c addition, as long as there is a RWD transmission that can be mounted to the rear of this engine once it has been turned longways and remounted, which I'm not sure of. Engine and transmission interchanges are not my forte. I really want to be able to maintain the digital dash. I have a 90, so I don't have to worry about the loss of the touchscreen.

Again, what encourages me that a RWD can be done is that it was done. So it's just a matter of determining if the work involved will be worth the headache.

[Guest F14CRAZY]

Hmmm...a Series II L67 would be good too. I can't recall though if the RWD and FWD 3800s have a different bellhousing pattern...reason I bring it up is that I dunno if a RWD tranny would bolt up to a FWD L67. I know there has been success in converting a RWD F-body 3800 to an L67 though

[jaredthegeek]

Bringing up an old thread, but this caught my eye.

I may eventually (barring sale/donation/wife calling a tow truck) perform this exact conversion on my 89. A coworker knows someone with a fab shop and has NASCAR-style frame-building experience himself. The thing we have been kicking around is:

1. Complete gut down to the sheet metal, seam-weld the unibody and cage/brace

2. New front subframe to accomodate unpowered front wheels (likely using a Camaro front clip since that´s what the fab guy likes), and a front-to-back motor mounting setup

3. Gut the brakes and go with an aftermarket non-abs setup. Wilwood is nice.

4. Motor TBD, my coworker is a SBC fan and thinks a nice LT1 would be the ticket though

5. T56 trans, likely from a Camaro

6. Vette IRS rear (though my coworker thinks a Ford 9inch on a custom 4-link would be easier)

7. Some form of side exhaust, my coworker wants lake pipes, I am thinking more along the lines of the NASCAR flat/rectangular-section things

8. Flush inset headlights OR low-profile pop-ups with a different actuating mechanism.

The steering rack was something I hadn´t thought about, but I would guess it could be moved up the firewall to clear the transmission, and the linkages extended.

Interior: Factory dash top, perhaps factory seats, but no electronics. I am a sucker for a nice set of analog clocks. Also eliminates the interoperability hangup trying to make stock parts work. Simpler is better, IMO. I want to keep the airplane cockpit feel, hence reusing the stock dash/console housings.

Inspiration: the KiMini (http://www.kimini.com), a carbon-shelled, tube-framed, rear-engine Mini with a Honda Prelude lump out back.

And why do all this? Because my (now 7-month old) son and I are going to build a car as he grows up, and this seems like it could be a nice long-term project :-). That and we would be very unlikely to see another V8-powered rwd Reatta tooling about NY. Track events or autocrosses would definitely be on the menu as well.

[shoreice]

I remember one thread about a RWD reatta with a BIG ENGINE. Anyone got the funny car picture?

[Guest F14CRAZY]

SBC? Naw, use a Buick turbo 3.8L V6 <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

Or if you still like big motors, a Buick V8

[Guest BUICKPOWER]

Kenny Bernstien has won NHRA World Championships in both Top Fuel and Funny Car. This Buick Reatta forever changed the look of Funny Car bodies

http://www.motorsportunderground.com/Jpage/Webpp/Pictures%20page%20two.htm

[Guest MauiWowee]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">SBC? Naw, use a Buick turbo 3.8L V6 <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

Or if you still like big motors, a Buick V8 </div></div>

Using the GN turbo 3.8 would be awesome. In it's day it was the fastest production car made in America. A V8 would have weight issues, unless you used the all aluminum Buick motor, circa 1961-62. I have always wanted to put one of those in a 1965 Corvair, mid engine configuration.<img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[Guest F14CRAZY]

A turbo 3.8L can make a lot more power, with a lot less money, than a SBC.

And hey! It's a Buick motor! <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[2seater]

The steering should take care of itself with a Camaro front clip, except maybe getting the steering column connected to the box. Maybe a Mustang II front clip also, another popular hot rod front end. Weight shouldn't be an issue as either one can be configured for the largest engines available, but the GN 3.8 or a Buick 455 if you like a V8, which weighs about the same as an SBC. I agree with your desire for an independant rear end. The unsprung weight is way better than a 300# Ford 9" and will ride better with a short wheelbase like ours. Underbody room will be at a premium unless a fair sized tunnel is constructed. The footwheels in a unibody car are set down pretty low under the car. It sounds like a fun project, and a big one.

[Guest spyhunter2k]

...and whatever you do, please document your progress. <img src="http://forums.aaca.org/images/graemlins/laugh.gif" alt="" />

[jaredthegeek]

The choice of the V8 was mostly an ease-of-use angle...parts availability and tuner knowledge. I am planning on a twin-turbo setup with one snail per bank, regardless of whether we wind up using a 3.8 or a V8 of some nature. Hadn't even thought of the 455 Buick as we figured a big-block wouldn't fit anyhow. We are planning a custom propane-powered setup (who needs a trunk on a hotrod?), with fallback to a Megasquirt-driven EFI rig if propane turns out to be a bust.

As far as possible, we will be adhering to the time-honored Q-ship principle... As externally stock as humanly possible! Well, ok, perhaps some fender flaring to cover larger rubber, and the exhaust routing is still up in the air due to lack of underbody space.

This is a Very Long Term type of project. My son is 7 months old now, so I figure by the time he is ready to start learning auto-shop, I can at least have the chassis mods done :-) By then emissions regs will probably be tight enough to necessitate an alternative fuel to pass.

[Guest F14CRAZY]

hey spyhunter I got thinking, as this was once mentioned on BC...

I THINK, if you wanted to, you could take the easy way out, and go AWD. The GM minivans, the Rendezvous, and the Aztek could have had "Versatrak", with independent rear suspension. The tranny is a variant of the 4T65E, and thus would bolt up to a 3800. There are stand alone tranny controllers so you could keep the stock ECM. Obviously would have to still deal with the tunnel and rear suspension, but not so much turning the motor 90 degrees.

It would bolt up to the 3800 and probably wouldn't have to change the front CV shafts. Not sure how the shaft clears the steering rack, but that may not be an issue.

But I dunno, the system's intended for a minivan and not a performance car, so I dunno how it would handle, and might not be what you're looking to do. Won't handle entirely like a RWD car, I don't think, but I don't know enough to say. Wanted to put that out there though.

[Guest TommyH]

all right. i like my idea much better than phills. partialy, because i came up with it, and because it soundes simpler. ipropose that you find an awd car, with a 300 in it, or an engine for that matter, and have a car computer specialist re-porgram the stuff so it iether doesnt need to see the enginek or it works with a differnt one. or not. the you cut off the body of the awd donor car. leave only things like suspensin and engine stuff. the remove wutever on the donor reatta that is on the awd car. mate the awd car with the moded reatta. fine tuning, put back the interior. ther you go.

[Don B.]

I think I'll get the video from TLC on the Jay Leno 'Toronado'.

Big Block front drive to rear drive.

[Guest spyhunter2k]

AWD is an interesting alternative, but I think it would be a shame to do so much work for only half the payoff. I want full RWD!!

I think Don is on to something. Find documented RWD conversions for other cars and copy as much as is applicable to the Reatta...

[Guest MauiWowee]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">all right. i like my idea much better than phills. partialy, because i came up with it, and because it soundes simpler. ipropose that you find an awd car, with a 300 in it, or an engine for that matter, and have a car computer specialist re-porgram the stuff so it iether doesnt need to see the enginek or it works with a differnt one. or not. the you cut off the body of the awd donor car. leave only things like suspensin and engine stuff. the remove wutever on the donor reatta that is on the awd car. mate the awd car with the moded reatta. fine tuning, put back the interior. ther you go. </div></div>

MUCH< MUCH< MUCH harder than it sounds. <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[Guest F14CRAZY]

Yeah I know what you mean. AWD might be like 65/35 or something

[Don B.]

AWD is great in the rain, my GMC Syclone will not spin the tires.

So the disadvatange is no smokey burn outs.

[Guest F14CRAZY]

Would AWD corner better?

[Guest trofeo73]

I was thinking of making the trofeo RWD as well. I have grown acustomed to the driving and handling characteristics of my IS 300. I would think that dropping the body on a rolling chasis would be the way to go. (after lowering and accounting for the frame rails so it doesnt look like an AMC).

[jaredthegeek]

My coworker is heavily in favor of the full-frame idea, though I think it might be difficult to do because of the unibody structure. I am leaning more toward a WRC-style seam weld and cage/gusset job.

I like the AWD idea in principle, but in practise, are the GM driveline components sturdy enough to stand up to non-stock power levels? Particularly in the case of forced induction and/or more cylinders?

OFF-REATTA-TOPIC:

Here´s a link to a gent in the UK who´s done a twin-turbo EFI V8

http://www.mez.co.uk/index.html