Jesuscookies

iTrader: (1)

I am currently building a 1972 RX 2 for street use.

Turbo/streetported- Laying about 400bhp to the rear wheels.

Do you guys have any suggestions on rear end set up?

I was thinking 9 inch?

would this affect street drivablity?

Any other options out there?

Wankelguy

You would have to do a lot of modification to the housing to get a 9 inch to work, but it has been done. Let me talk to a friend of mine who knows more about it, and I'll re-post when I have more specific information for you. -Mike

Rotortuner

If you go 9 inch, the housing will likely have to be cut and shortened along with the axles. I have a friend thats going the same route but with an r100. I think the 9 inch might be the way to go for you. It will defenitely handle the pwr, but its not going to be really cheap.

CJG

Rotortuner

I just talked to my friend about custom 9 inch set ups. And as far as having them narrowed doesnt seem to be that expensive. For example, we have a local shop here that will narrow the housing for like $90, and then for custom axles its about $350. So thats about 500 to modify it to make it fit. Then its just a matter of getting a drive line and mounting it in. So your looking ar around $1k probably, once you get the actualy rear end its self. Not too expensive though, and it will pay off in the long run.

CJG

Jesuscookies

iTrader: (1)

Thanks for the replies.

I have about a grand to spend on this part of the conversion so I would be right on budget.

Initally, I was a little concerned about the conversion, because of what others have said about the driveibility of the car on road with a 9 inch. ( I really do not understand this though?)

My 2 options appear to be modify and put a 9 inch in, or modify and put the Kaaz in. I think the 9 inch will hold up better than the Kaaz in the long run. The 9 inch will be cheaper as well.

What are your guys thoughts on this?

Again, I am really only concerned about 2 things.

Road Drivibility, and durablity.

I mean, what's the use of having 400HP, if I cant lay it to the ground on occassion

Also, Rototuner if you could PM me with the name of the shop that is could do the mod I would appreciate it.

David

Wankelguy

Wait a minute, am I missing something here? Doesn't the RX2 use a 4-link setup in the rear? So you would have to weld on the brackets for the 4-link as well as lower shock mount positions as the RX2 has a coilover shock as well. Right?

Rotortuner

Your right WG, Thats why i said it would have to be narrowed and then a new drive line and "make it fit". A lot of it depends on what type of rear suspension he wants to use. If he wanted to stay with the stock set up, then it should only be a matter of welding some brackets. right? I am no expert but I am no dummy about this stuff. So i said he would have to spend about 500 to have it narrowed and then that laeves him 500 more to play with. I dont know how much it costs to buy the actual 9 inch to have customized? Plus hes going to have to play around with brakes a little and stuff too. If he cut off all the brackets off the stock unit and welded that himself he could save himself some money their too. Its just when you start buying like all brand new rear brakes and stuff is when you get into some more money. I guess i would up the estimate to mabe around 1500 or so?? Just depends on how much you can do your self and if you want it all brand new, and how cheap 9 inch rear ends are.

CJG

Jesuscookies

iTrader: (1)

This is where your guys knowledge far outstrips mine. I know very little about the suspension set up. However, as part of this build up, I will be re-doing the suspension. Again, the whole idea here is that, once I am done, I get a perfomance, street worthy car, that will handle 400Rwhp.

Everytime I type 400Rwhp, I get goose bumps

So are there other alternatives out there with respect to making the RX 2 handle better?

Point me in the direction of what I should be looking at. I have budgeted another $1000 for the complete front and rear handling/suspension upgrades.

Thanks

Flamin' NOS

I hear that a Mustang 8.8 rear is a better deal. Lots of parts available for cheap, none of the V8 guys want the 8.8's because they can't withstand huge torque. They can handle rotaries pulling wheelies though. I havn't measured one, but I hear that they are almost bolt in as far as width goes.
steve

Wankelguy

I think those Mustang rearends are great. My friend had one on his GT3 RX3, which ran a 300 hp bridgeported dual-distributor 12A, and did 165 on the straights. So I would think they would be plenty strong.

Rotortuner

Wow that mustang rearend sounds really cool. that might be a cheaper alternative to the nine inch. I mean the nine inch is supposed to be ausome but, if that mustang rear would be almost as good then mabe you should realy consider that.

CJG

RacerX7fb

Racing Beat has front end adapter kits for the RX-2.
www.racingbeat.com

Jesuscookies

iTrader: (1)

I will defintely have to check out the 8.8 rear end.

I have also heard of people using the Jaguar rear ends. I do not know how practical that is with respect to part availability.

Thanks RacerX7fb. I was planning on adding that suspension upgrade that racing beat offers. However, I think I should learn a little bit more about suspension design, so that I know what in the hell it is that I am trying to fix!!!

Does anyone have any experience with the "GROUND CONTROL" suspension products? I know they make coilovers for the RX 2?

Wankelguy

The Racing Beat "stage 1" and "stage 2" kits work okay, but a custom front swaybar can accomplish the same goals without installing a bunch of hokey spacers. I had an idea for making the caster angle adjustable by threading a longer portion of the swaybar. The "arms" of the swaybar also need to be straight, without the bend in the middle of the stock unit. Then the car needs to be lowered until the front swaybar is parallel to the ground, which isn't much, maybe 1-1/2 to 2 inches. The top strut mounting bolt holes can be ovalled to adjust the camber. As for the rear, if Ground Control makes it, it probably works great. I wasn't aware that anyone was making performance rear shocks for the RX2 anymore. Koni used to make some nice adjustable shocks that had the spring perch on 'em for use on the RX2, but that's been about 25 years ago. Although I can't remember his name at the moment, I spoke with the owner of Ground Control a few years ago, and he seemed pretty knowledgable about how to set up the RX2s and RX3s. Another guy to talk to is Glen at Quickor, which is here in Oregon. Heck of a nice guy, and knows the old cars as well. Just some stuff to think about. Good luck! -Mike