Has anyone tried a pair if GT35R's on their "big" ported 13B ? I am going to upgrade my twins now , and I'm thinking of going with the next bigger one , the 3076R , but my friend is trying to convince me that a pair of GT35R;s with 0.63 a/r turbines would be abetter choice , what do you think ?

 

Welcome to lag city.

 

Isn't that what Bobby Freeman did with his car? I thought that was what he and Demetrious were cooking up? I bet it would kick *** if you had really small hotsides.

 

His weren't 35Rs, IIRC.

 

its worth it if your road/circuit racing.... because your going to be in the 7k+ rpm area the whole time... and thats where you need the power

but twin GT35Rs are useless... go with GT30R's at the most

twin GT28Rs will also be nice.


i remeber seeing Huy's (sp?) blue FD with twin GT30Rs at SS9

 

Of course I cant say for sure 'cause I havn't tried it ,but I find that a bit hard to believe after experiencing the 71's . I also saw my friends bridge ported 13B spool a Gt42 and a GT45 , both with 1.32 hotsides (I think) from 3500rpm up , and those wheels are huge in comparison . I know my car isnt a full race car , but I just want to make sure I get the most I can get for the money this time , because I dont want to do this again. maybe its time some one comes up with a rotary engine / turbo matching program ?

 

http://videos.streetfire.net/video/4...7a0027d0e1.htm
twin but on a 20B

*edit*
personally...if I were to go twin, I'd follow howard coleman's lead blocking...

 

I'm just making an educated guess, I'd love to be proven wrong. I say go for it, nothing ventured nothing gained

 

Someone in Japan has, or maybe it was two T04s turbos. The have very similar compressor maps. He's on Nopistons. I think he has a McDonald's symbol in his sig.

 

I know all about Howards set up , but I run a semi pp motor , I am sure the VE of my motor and his streetported on is different ! I am 80% decided on the GT3076's but the idea of twin 35's just makes me feel all tingly inside ! if its possible then I WILL try it !

 

What boost level are you going for at peak engine speed?

 

I'm shooting for a max of 25psi

 

it's gonna take a hell of alot of work to spool up 2 large turbo's.. this is not to be compared with spooling 1 larger turbo because you are halving the exhaust flow to each turbo. if you want a 2-3k RPM only powerband then yeah this may work but that is a huge setup with no real reasoning aside from big power with a narrow power band.

ever seen a 250lb guy ride a KX80 motorcycle? similar situation here.

 

Every one comes on and makes unsubstatiated claims about spool and powerband , but do you know that there is someone who used a pair of 60-1 turbos on a 13B and there was no problem spooling them ? his problem was SURGE ! yes the exhaust volume is halved , BUT the rotational mass and inertia are also halved (and may even be less because of their bb config.) . I have seen a bridge ported 13B spool a massive GT 45 ,non bb turbo by 3500rpm's without a problem too ! I am confident that my motor wouldn't have a problem spooling them , my question is about compressor SURGE ! if the turbos would spool too early resulting in the combined flow being too much for the motor too soon , that is the question . I guess I may have to do some studying and see if I can figure it out on my own.

 

Well, to combat surge get the anti-surge compressor covers and you're good to go.

Marcel, why not get your current setup optimized/tuned and get some juicy dyno numbers for us? With 20 psi by 3500 rpms, sounds like you have a killer setup already! Also, do you have any updated pictures of your car?

 

http://www.kiwi-re.com/gallery_11.php

IMHO i would go with two garret GT3076R's. i think GT35R's are to big for a 13B (tough i know semi pp helps) and you would be better of with something not as large. just FYI Abel Ibbara ran twin GT35's on a FULL pp 20B (he ran 45psi or so if im correct and made 12xxrwhp) on his K&N rx7.

 

If you are targeting 25psi max, two GT35's are absolutely too big.

 

Bobby had a lot of problems with lag so they went smaller. I havn't talked with him in awhile so it may be worked out by now.

 

hahaha

 

I hope you take some of the advice that I'm offering to you to not go with twin GT35's. You will likely not hit more than 25psi before 6kRPM and have only ~9psi holding up until then.

I recommend just getting a GT35-40 frame sized turbo if you are targeting 25psi. If you are set on twins, then go much much smaller (20-25 frame size)

btw, I am not guessing.

 

At the moment I have my setup "apart" , I managed to pop my rear rotor so I have started the repair prosess. I suspected it was caused by my larger FMIC , but after Howards pm , I'm thinking that it could have been a combination of the IC and too small a/r's on my turbines .I'm guessing that the extra flow allowed into the motor by the IC, caused the back pressure to go even higher .
It wouldn't be wise to try to "optimize" my current setup , since there is a chance of this can happening again , this is why I have opted to change the turbos as a whole. i will post updated pics when I put everything back together.

 

Whose bobby , is he on the board ?

 

Bobby Freeman:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/my-twins-584134/

and

https://www.rx7club.com/single-turbo-rx-7s-23/reactive-racing-twin-turbo-kit-370776/

 

Marcel, this dude^^ works for Garrett and performs testing for them.

 

Man was that soo hard to say ? if you have info "on good authority" then y not just say so ?