Compressor A/R bigger than hotside?
 

Hey, I was at the junk yard today about to take a turbo off of a diesel ford that got t-boned when the guy came up to me and told me he wanted to sell the whole engine... then he said that he had a new turbo in the office. So I went and looked at it, brand new, you could lick it :p:
Anyways... it had a 1.00a/r compressor and a 0.85 turbine or hotside or whatever... Ive never heard of it being that way before. Is there any advantage to this? Maybe spools faster and flows more air?
I dunno...
Would this work on a 13b?

Thanks guys :)

This does make sense for a diesel engine. Having heavier moving components (piston, connecting rod, etc.) they dont rev very high therefore dont really create much for exhaust flow so a small exhaust a/r would work for them. They can, however, sustain relatively high amounts of boost, hence the large compressor a/r.

Rotaries, however, are the almost exact opposite. They can spool turbos with large a/r's, (at least partly due to the high egt) but can't really take boost worth a shit.

In conclusion, I don't think that turbo would work for you. BTW anyone can feel free to correct me as these are mostly theories based on MY knowledge.

the only thing limiting how much boost you can run in a rotary is your fuel supply, oh and of course how big your balls are

Plus, you need platiunum coated "flux - capacitors"!

lol so whats the deal guys? I have the fuel to run a good amount of boost... Just wondering how this turbo with that a/r combination would work on a 13bt :)

I don't think it would work very well at all. I suppose I should have said that rotaries can't really boost tons on pump gas...I guess maybe it takes more octane for a rotary to be able to run the same amount of boost as a piston engine?

uhhm no.... i run 18-20lbs on 93 octane pump gas for the last several months... it all depends on your timing and how efficiently that air is compressed. using a less efficient smaller turbo will creat alot of heat at that level of boost and will be prone to detonation...but with less timing and better efficiency i.e. my t78 i can run these levels... just liek a piston engine. i

well fuck. There goes that theory...

this turbo would work fine if what hes looking for is low end boost(of course if the turbo is sized rigth in its otehr specs). having a larger turbine/hotside will cause you to build boost later and have a higher top end horsepower

possible backpressure problems with those a/rs.

true it may actually overspin the turbine since the rotaries make alot of exhaust at higher revs..

Hi Bros,
I have a series4 13bt with portings done and 8 injectors running with a microtech MT-8. The problem I'm facing is my turbo. It's a TO4E, but with a rather small Hot side. The compressor has an AR.70, what can be the down factor for this setup? My car is a first gen rx7, and will be boosting u till 25psi on semi-slicks. What do you think of my chances in the 1/4mile against the 500hp evos and wrxs? Should I upgrade my turbo?

i have yet to personally see a 500 hp wrx or evo..so i dont know

Well, there's a 500hp evo, running full HKS setup 2.2L block, with a HKS TO4R boosting up to 2bar, except using a microtech LT-8. Trust me this car is fast. Seems on par with an 800hp skyline with hollinger gearbox. But not 1/4mile, but just 300meters drag. Anyway, back to my question should I upgrade the hot side of my turbo to a larger housing? Will be heading for the 1/4mile drag next mth. Thanks!

you're going to run 25 psi on a t04E?

what are the specs on the turbine?

what do these evos and what not run in the 1/4?

as for the guy's thread that you highjacked....

i'd say that you would probably have backpressure problems with that small of a turbine....the compressor sounds huge though. it will probably spool up very quickly giving you lots of boost down low and then choke off pretty badly up top.