Need help

[RB25240kouki]

Hello everyone. I used to want to buy a 240sx and put the RB25 skyline motor in it. But 240sx's have proved really hard to find and I found a great deal on a 89' GTUs. First off Id like to know what the differences of the GTUs to the GTU are and the differences from a GTUs and a reagular rx7. The car I want to buy has 154000... which I know is high but if I were to buy it, the first thing I would do is have the motor rebuilt and street ported (does anybody know of any good rotary shops in Georgia?). Also what are some good turbo kits for it (not to big... i dont want to wait untill 6000 RPM just to get boost). And does anybody have an idea of how much it will cost to have the motor rebuilt. Thank you for your information. Mike

[flex339]

From what I understand the Na motor can't handle boost very well and can't be boosted very high at all. The best bet is to buy the Turbo 2 powertain, but thats pretty expensive.

[RB25240kouki]

Why cant it be turbo'd? I thought the main thing with turboing a NA motor was the compression ratio. And isnt it the same between the NA rotarys and the tubro II rotarys?. And I dont think they had any other difference other than the turbo of course. I may be wrong but I some how I think Im right. But I still could be wrong. Look forward to feedback!.

[Soyo]

or port the engine and rebuild it with the rotors and stuff from the turbo engine... I'm pretty sure that works good... rebuild and port will be between 1500-2000 probably

[dayna240sx]

First off the GTUs is the IMSA homologation car. They are very rare.. in 89 Mazda made like 3000 of them and in 1990 only 100. I myself have an 89 as well... and would love to find a White 1990.

Main differences is the transmission gear ratio's, and rear axle gear ratio.

In the trans for the GTUs its 5th speed ratio is: .756 where the standard N/A is .697.

The stock rear axle ratio for N/A cars is 3.90, and 4.10 in turbo cars, where as the GTUs has a 4.33 rear axle ratio.

The GTUs were equiped with 16" wheels identical to the same year turbo cars, rather than the 15" wheels the standard GTU cars came with.

The GTUs is pretty much a stripped down lightweight version of the RX-7.. Power nothing, no power windows, locks, etc etc.

Concerning your power upgrades... I think all of you RX-7 people have it all wrong. especially the thread starter.

Why throw a TII drive-line into such a rare car? I am selling my GTUs to a very good friend and rotary fan. Our plans are simply to rebuild the engine, build new exhuast for it, trim some more weight, tires/wheels, shocks/springs, sway bars, Hawk pads, SS lines, and lots of reliability mods. by the time we are done he will easily be faster than even a mildly modified TII...

If you do tear out the engine, I'll gladly buy it from you...
If you do a TII swap you'll need the entire drive train... from engine to Diff. so by the time you buy the GTUs, and the TII drive-line you may as well buy a TII to begin with.

How much is the car??
The RX-7 is certainly a better car than the 240, so i must congratulate you on that, but lets talk more before you ruin this car.

Consider talking to me via aim sometime... but i the meantime here is a game plan.

have Kevin rebuild and port your engine... he is close to you, depending on where you are in GA.
http://www.rotaryresurrection.com/

talking about $1300 plus shipping... I would go ahead and get new, or newer rotor housings...

and... the invest in a lightweight Flywheel and clutch.

http://www.clutchandflywheel.com/clu...lutch_kit.html

$ 899

replace all your fluids while you are waiting for the engine... redline in the trans and diff, all new brake fluid (atleast DOT 4) change to SS lines, new pads (hawk) replace shocks and springs as needed. wheels and tires (All my rotaries have TE-37's... but there are alot of other wheels out there... get a light wheel, 16*8 for best handling)

Talk to me about proper rotary exhaust design. (dont' go out buying crazy fart cans for your poor RX-7)

At this point you will have a killer street car, 2 or 3 steps away from race car.

[RB25240kouki]

Im going to go buy or not buy the car tomorrow. The origional engine is out. It has 1 bad rotor and 1 bad housing. It has a series 4 in it now with all of the other stuff from the origonal on it (motor had to be modded a bit to fit some but none of the stuff of the 5 was modded). The series 4 has 800 miles on it since rebuild. I would be able to send off the motor to be rebuilt and still drive the car (Whoo hoo!). But what I want to do is turbo the origional motor ... I dont care if it is rare ... I mean its not a copo camero or anything (dont ask why I know about that car). What Im asking is (which has partialy been answered) is can I turbo an N/A motor (espically since im having it rebuilt and i could use turbo rotor housings). And does anyone know of any kits to do so. If there are no kits to do so its possible to rob parts from some turbo IIs and put it together with a turbo II upgrade kit? Also the car already has a "stage 2 clutch" new exuast (ricey... must replace). It has a little body damage (bunch of door dings, small dent in front left fender, and a door problem that i couldnt understand... but will find out about when i go to see it. Thank you Dayna240sx for your info ... Im glad someone knowlageable has replied. KEEP IT COMING EVERYONE!. Ill update on wether or not I buy it tomorrow morning! Mike

[ShortyDTP]

Got Damm dayna I need to start hanging around with you more often!! Yup when i grow up I want to be just like you!!!!!!

[DevoutWankelist]

Look, since you dont care if its rare or anything and you want to turbo the motor anyway. . . I will trade you my 91 Gtu for it? Then youll have power windows, power mirrors, new clutch, new tranny. But theres no way in hell its passing emmissions (no cats), so. . .

[Soyo]

91 GTU? no such thing! 91 only had Coupe and TII models. I have a coupe with power windows, doors, mirrors, and sunroof... I'd expect your talking about the base model coupe, just trying to clarify

[RB25240kouki]

Originally Posted by DevoutWankelist

Look, since you dont care if its rare or anything and you want to turbo the motor anyway. . . I will trade you my 91 Gtu for it? Then youll have power windows, power mirrors, new clutch, new tranny. But theres no way in hell its passing emmissions (no cats), so. . .

umm... no