Rotorious7

iTrader: (1)

Has anyone done a successful rearend swap for 1st gen. I have a turbo 1st gen and would like to upgrade .

i have heard- Ford 9", Mopar, Toyota truck, Nissan Truck, and even heard to gas nitrate and stress relief the oem Rear end

What would be suited for a street race car an occational dragger

Rotorious7

iTrader: (1)

no one done this swap out there

treceb

I dont believe Ive seen any of them swaps for a street car. Theyre everywhere on race cars, though.
I dont know what year, model RX7 you have, so the only suggestion I can give you is to get a GSL rear end, to keep the same bolt pattern, or a GSLSE rear end, but the bolt pattern will be different. The best thing, IMO, would be to find shell of a GSLSE and swap front and rear suspension into your car.
laters

David88vert

From what I understand, there is a Torsen rear end upgrade available out of the early Miatas. Also www.grannysspeedshop.com has a Ford 9" upgrade. If you want to do something like this, call James. He and David have already looked into it I think. I will probably go with the Torsen upgrade myself later on.
You could always go simple and put a GSL-SE rear end up under it for now. They handle a good bit, but you would eventually have to replace it. David Lane is pushing 275hp on his Cartech setup. You could look at what he is running. David Randall has a TII setup on his GSL-SE motor. He has a website for it also.

MarkPerez

The ford 9' inch,,narrowed,,with D locker 3rd member,would weigh a lot
for a RX 7, and rob a lot of power,even the 8' inch would do the same
unless you go V8..if you've got a GSL then your disk brake and LSD
allready,,oh,man a 31 spline,D locker,N case 3rd member,in a 9' inch
narrowed ford with disk brakes on an RX 7 would be indestructable..
or in any car for that matter,,,that,,with some wheel tubs and some mods to the suspention ( 4 link) so the wheels fit " IN "or under the
car..some 10 inch,or more size wheels ( deep dish) would be BADASS !!

mar3

iTrader: (8)

With slicks, he'd either bog the engine all the time at launch or take out his tranny. Since he's looking for domestic solutions, throw in a Liberty 6 speed clutchless sequential transmission so he'll have a bulletproof drivetrain. With this combo, he'll have to have a custom titanium driveshaft to survive repeated 9000 RPM launches on the bottle. What's that? He's too light to need that much driveshaft? Have you ever tried to lift a 9" rearend? OH MY GOD, there goes my back!!:p His car WILL become heavy once he's finished with all the details necessary for that kind of a rear-end swap........

Rotorious7

iTrader: (1)

well the car will be estimated over 400 + horsepower
with a turbo 2 tranny conversion. i will welcome some weight

the gsl rearend will not stand up to the power esspecially with dual friction clutch

my car is running a 3rd gen motor with cartech blow through with about 300+ horses now

David88vert

BTW - James said you needed some 260's for your carb. David suggested you get 200's and have them drilled like he did. Call James or David and David can tell you more, if you haven't already gotten them.

Rotorious7

iTrader: (1)

thanks, i will email dave and see if he has the bits i might need to do some drilling (drilling for that gusher)


checking out grannys web site now

David88vert

He had some guy do it for him. He went to 240's

Rotorious7

iTrader: (1)

actually 240 is my next step up before trying 260

David88vert

I am pretty certain that you will need bigger than 260's actually. I saw the video from the dyno, and you are making some serious power. You seem to be needing more fuel. David wasn't making near the power you are, and he needed 240's.
BTW - I am the webmaster for the SE-RX7 website.

Rotorious7

iTrader: (1)

i think u are right on that fact. my thinking was to gradually take steps in minor increments so i would not second guess myself. Also need to run colder plugs and maybe experiment with emulsion tubes


have any suggestions

BY THE WAY YOU HAVE DONE A GOOD JOB WITH THE WEB SITE!!!

David88vert

I can add you to the members if you send me the info. Look at the other members pages to get an idea of the format.

It is much better to run to rich than too lean. Go ahead and get some serious fuel dumped in. You cna always up the boost that way. What are you doing to seal the carb so that you don't get boost leaks and spiking?

Have you looked in the Denso Iridium plugs? They are much colder - specifically for setups like yours. I use NGKs, those are the only others to run.

Rotorious7

iTrader: (1)

DEFINATELY WILL SEND MY INFO. I MIGHT COME BY THE EATING PLACE BEFORE SYMS TOMORROW

Rotorious7

iTrader: (1)

GRANNYS WEB SITE HAS FORD NINE INCH FOR 525.00 US AND HAS ALL THE MODS TO BOLT IN

mar3

iTrader: (8)

You sound like you got some donero for this kind of swap so go with strength without all of the weight. At 400 rwl HP, a chevy 12 bolt or mopar 8.8 will hold up to launches on slicks on a dumped clutch technique. Neither comes close to the weight penalty of a ford 9" but their ultimate strength doesn't match the 9" either. The ford thing is overkill unless you're pushing 500+ of TORQUE on a 3500 lb. car. The driveshaft will either have to be good grade of steel or an oversize tubed aluminum unit to match the disimilar drivetrain pieces. Your tranny will be in peril. No idea how to address that weak link.

Rotorious7

iTrader: (1)

ACCORDING TO GRANT @ GRANNYS THE MOPAR HAS BIGGER DIAMETER AXLE AND THE GEARS RUN COOLER BECAUSE OF DESIGN. ALL I WOULD HAVE TO DO IS BUY A 3RD MEMBER AND PUT ON DISK BRAKES (FROM 2ND GEN)

mar3

iTrader: (8)

If it's the 8.8, then that's the way to go. Unless you launch on slicks on the bottle, you're not going to hurt that hunk of iron...

Rotorious7

iTrader: (1)

grant calls it an 8 3/4 narrowed mopar rear. i will be happy if i touch into the 11's with this baby

i want to set this car to handle 150 to 160mph w/out stressing

peejay

RiceRacing runs a Series 2 rearend (meaning '81-83) with a competiton limited-slip, and he's pushing 500+hp from his turbo engine... (40-70 in 2.1secs spinning the tires... !!!) says he has to replace the axles every 12kmi though. Theoretically the '84-85 rear has stronger axles, but wossisname from Pineapple says the pre-84 rear has a stronger housing.

Hmm.

http://www.rx7forum.com/showthread.p...hlight=rearend

is where I got his info from.

(note "S1 rears are weak..." Yep...

mar3

iTrader: (8)

My Pontiac bias is showing...8 3/4 it is for a Mopar. 8.8 is the baby brother to the Ford 9". And, please...his name is Rob Golden. If you want to learn how respected this guy is, go to the newstands and pick up the latest GrassRootsMotorsports magazine after you pick up the latest rice rags.

Rotorious7

iTrader: (1)

What is the difference between series 1,2 and 3. is it because of the different years of the 1st gen production.

peejay

S1 = SA22C = '78-80.
S2 = '81-83
S3 = '84-85

Big differences between S1 and S2 as far as stuff like body, engine, transmission, and brakes. S3's improvements on S2 are related to stuff like the different rearend, different instrument cluster, different rear suspension pick-up points, and probably a souble other things I can't think of 'cos it's almost midnight and I'm getting foggy.

FWIW - (my 2 cents again) I'd rather see someone swap in a 9" over an 8.8" because, while heavier, the 9" has more aftermarket support, and the 8.8 has C-clip axles while the 9" has a setup like ours with a separate pumpkin and the axles are retained by the bearings. C-clip acles are held in by a little C-clip inside the differential carrier... if an axle breaks, or if the C-clip breaks (and yes, it DOES happen, I saw it happen to a dude with an S-10 last month) the axle is NO LONGER HELD IN and it WILL come out, leaving you with no wheel or brakes! Once you go past a certain ET they mandate something called a C-clip eliminator, which retains the axles similar to how a 9" is done, except the axles and housings aren't really meant for it, meaning you can't put much side loads on the rear (no more cornering fun) and they usually leak all the time. Why bother getting an 8.8 and then spending a lot of money to half-*** it when you can just get a 9" (which is also much stronger, pinion gear supported on both ends!) and not have to worry about it?

Also FWIW a stock, normal 9" (meaning no hard to find nodular cases etc.) has a 750hp rating... think that's strong enough for ya?

This guy runs a 9"...

David88vert

I don't think that I will make it to Syms tonight. Just bolted everything back in the GSL-SE, but I have a strange scrapeing noise. If I get out of work early today, I might be able to fix it in time to go. I really need to get to Dynolab tonight to see Arthur anyway. Need him to fill up my NOS bottle, and to talk to him about his website (I build it also.) and my dyno tuning.
My GSL-SE is the ugly one with the rollcage.