Have been looking to go GT42R for some time now and I will be doing it sometime soon, I have a question about injectors though, currently I am running 550cc primaries and 1600cc secondaries. I am pretty sure I am going to need some larger primaries, is 850cc enough for 700hp or will I need to go larger in the Primaries?

Also, the motor is fresh rebuild only maybe 3k miles and 3mm seals in less than 2 years but not studded, are there any stock size stud kits that can handle 700hp or will I need to get a larger then stock size kit for holding that power?

One more thing, do I need a different e-shaft with this power? It won't be revving over 8,000 rpms ever. I heard of people having to go 2 piece, but that's really putting the dollars down...

 

Quick Answers that i know.

Stock E-shaft will hold,have the assembly balanced you should be good from there.
Studs? some people have mix feelings about this subject,personally from reading other peoples opinions on studs,dowel pining your engine will be enough to hold that Hp,tuning is key.

Hope this helps Good Luck

 

Thanks for the input,

I have read a bunch of threads on dowel vs studs but everyone says different things and I just fidured I could make it simple with studs

 

You don't "need" any of those things listed... But the difference in a 400whp rotary engine build and a 700whp is a lot more than people think. IF you wish for your engine to last, you'll need, above all else, a tuner that knows big hp rotaries.

-J

 

Stock e-shaft will be fine, you'll want to get your assembly balanced and I would say for reliability reasons clearance the rotors as well. Studding or dowelling will work if the person doing it knows what they are doing if not expect cracked plates.

~S~

 

Use stock size studs if you want to avoid machining,but to be honest i don't think they're gonna be much help at all,like i said many others tuning is a huge factor.


Here's a couple of threads of 700hp rx-7s

https://www.rx7club.com/single-turbo-rx-7s-23/pfs-741rwhp%4027-psi-821290/

https://www.rx7club.com/auxiliary-injection-173/703rwhp-34psi-pump-fuel-water-only-injection-863250/

 

thanks a ton for the input guys, quick question, what kind of ECU do you run for more than 4 injectors? Since it looks like I will need 2 more

 

Run 2200cc injectors 4 of them with a platinum sport 1000 you will have no problems for 700rwhp

Dowell the engine.

Make sure its ported by someone who has product good power before hand.

 

More important question... What fuel are you going to be doing this on?

 

4x1600's stock e shaft properly tuned @ 30 psi( 76mm )700 whp to the ground ....... porting is a "whatever" imo
AIT's are the most important factor I recomend w2a

 

I would like to be doing this on 93 pump fuel, of course I will be running water injection as well.

So it seems that after reading up about dowel pinning, it is for a small margin of error when tuning. Obviously everyone has different views on it, but most people say that if someone knows how to properly tune the car and has only the minimum margin of error dowel pins wouldn't be necessary. I still plan on pinning my engine, I just am trying to understand it a little better...

 

porting can be compensated with more boost, as long as you keep AIT's down.

+1, W2A rules.

 

93 pump ??? hope you have alot of water !!!!! the c/r is extremely high at 30+psi
and timing is key to making HP, but to each is own......... you could have the engine w/ a stud kit and still have problems w/ the "bang" I highly recomend dowel pinning jus make sure it's a perfect fitment or you will run into some crazy stupid problems. trust me been there n done that I was off 2-4 tho on my holes and lost compression due to sealing. if done correctly works great !!!
my jig moved jus a hair on the mill without me knowing and HELL was the outcome

 

Here's a link to a place that does dowel pinning,other **** you need

http://www.rotaryengine.com/services/studding.htm

 

My car makes 700+rwhp on your 93 octane fuel with water and its dowelled. I do the dowelling in house.

 

I too am looking for around 700 on pump fuel. I decided to be safe instead of sorry so I put in oversized studsa and a 2 piece e shaft, no problems so far.
I am running 6x1600cc bosch injectors with 2 '044's in tank.

 

Studs? From my experience that will be your down fall. But hey what do i know

Hope you have a few spare engines lined up for 700 on pump. I did. Unless youve done it before i highly doubt it will be something you get right the first time.

 

I guess I'll see !

 

WOW !!! let me Guess 93oct w/ 10% eth ???

Like I said to each is own

 

umm no. 100% pump fuel with no ethanol.

just cause you cant do it dosnt mean everbody else cant.

 

Two years straight, same engine, over 200 passes so far, last season... 780whp, this season... 866whp, stock e-shaft. Still 110psi compression on the same engine, STUDDED no issues whatsoever. This is running two different sets of apex seals front to rear as I wanna compare wear on materials. The moment I switched to studs years ago my problems went away, you say the moment you switched to dowelling your problems went away. Maybe I sucked at dowelling and you sucked at studding, just a thought


~S~

 

Innuendos????

 

Waaaait a sec!!!

 

WOW !!!!!! I Wonder if it's still 93oct ???

 

Amazing how chidish people can get when they get put in a corner. Zero R thats fair enough mate. I cant argue with your results. If that works for you then your doing it right.

Some of the other people in this thread are amazing.

If you can only produce 780rwhp on your beloved race fuel and you think porting means nothing. You need to go back to your drawing boards and start again.