hey, im new here kinda n00bish, but have been browsing these forums for a while...



Just wondering, what do u guys reckon is the biggest turbo u successfully fit to a rx7...custom of course. Would there be much point in having a turbo much bigger than a HKS T51R KAI?

Im kinda new to rx-7's..but ive read around a bit and have heard that at stock the Fd's cant take anymore thn 11 or so psi..? is this true. I think i heard that the stock turbos cant take much more than this. For a racing rx-7 what would be the highest boost u could put through the engine? I heard somewhere 30 psi...would someone dare put this boost through a 13B?



cheerz, Volod.

 

ok the size of your turbo is determined on how much power you want to make and where in your rpm range you want to make it. that said, theoretically you could put any turbo on any motor but it doesnt mean it will work



now what you say about the stock 13btt is true it wont hold much more than 11-14 psi on a stock motor due to the apex seals but Abel Ibarra runs 30 psi on methanol on a 13bt

 

hmm, i spose i didnt word it right. I was trying to say, would there be any point in getting a turbo bigger than a HKS T51R KAI? would one of these pump 30psi at 7500rpm? what type of apex seals can hold 30psi?

 

Unless you plan on making over 700 HP then don't bother going bigger. That turbo will make 30 PSI no problem. Stock 2mm apex seals can handle 30 PSI, but the tuning has to be good. I like Hurley 3mm seals, but everybody has their own opinion. 30 PSI can only be done on race gas, and it may require dowel-pinning the motor, depending on how adventurous you are.

 

well yes i've seen bigger turbos than the hks unit your talking about on rx7's but most of them were straight up drag cars. now you ask if there would be a point in getting something bigger than it, well it would depend again on how much hp your looking for if that turbos only rated for 500-600 hp then if you want 700 your gonna need something bigger.



now to run 30psi i know you would have to pin the motor and get 3mm race seals but im sure theres more than that to it. now i got a question of my own. why in the hell would you want to run 30 psi?

 

The 11psi you talking about for a 3rd gen has nothing to do with the motor or turbos. It has to do with the ecu. The ecu wont supply fuel for more than 10psi which is stock but at 10psi it is rich so you can turn it up to 11psi with a few mods. You go past 11psi and your running lean with the stock computer so you upgrade it and turn up the boost. The next hurdle is the IC which should be upgraded around 13psi of boost in my opinion. The next after that would be the fuel injectors and pump at 14-15psi depending on how good your tuning is. At that point you are basically running the stock turbo for everything its worth for all practical purposes. You can jack it up to around 17-18 for a drag race but you couldnt drive it like that for any length or time, it generates too much heat which isnt good for the motor.



As for the T51R, like everyone says its basically too much for the street as it is. There is no need to go bigger as it will make enought power to run super low 9's.



STEPHEN

 

the 30 psi was theoretical...i wouldnt try it - i was actually just asking how much boost a well prepared rotary can take.

13BAce - u talk about dowel pinning the motor. I know what dowel pinning is...but where do u do it?

 

I've seen a few, but I forget the exact spots the dowels were in. I'm going to get mine pinned by the winter. So I can tell you where they are when I get it back.

 

Some places reccommend adding extra dowel pins, for support under high boost pressure. Dowel pins are what hold all the housings together.

 

You're just adding extra dowel pins between the rotor housings and side housings.