ihi rhb5 vs. t25
 

alright ive been researching the t25 and it seems to be somewhat comparable to the rhb5 ive got(the biggest of em all i believe, the t-bird one i guess still not too sure what its from, also has the T3 exhaust housing flange) anyways the rhb5 needs a rebuild and i can get a good deal on the T25.

the car is being set-up for autocross so i need the instant spool of the small turbo's, and im not sure which one would be better of the 2...i know the T25 will be at full boost a lil higher than the rhb5, but hold its own up top unlike the rhb5.

anyways just wondering which one will be better for what im tryin to do.

*o yea its on a z6.
bored to 75.5mm
eagle H beams
je 9-1 pistons
clevite bearings
commetic .51 HG
balanced rotating assembly
Stock z6 head.

Re: ihi rhb5 vs. t25
 

either of those are too small for anything but a stock honda, do you roadrace a honda below 3500rpm? noo... get a bigger turbo.

Re: ihi rhb5 vs. t25
 

sometimes u can be below 3500 rpms on a solo course. u never get outta 2nd for the most part...

Re: ihi rhb5 vs. t25
 

For autox you obviously dont want such a big turbo that you have tons of lag and insta power when it kicks in up top... That would break the tires loose and be tough to modulate. But you also dont want a turbo so small that you get insta boost in the real low rpms either... Why? Because when you come out of a tight turn in a FWD, you need time to straighten the wheels before giving it full power anyways. As soon as you get straight you would be glad to have more power up top. Most of the time you save is in the fast sections, not the tighter/slower areas. I get full boost at about 4k rpms on my 42/48 t3 and id like a bigger turbo for straight line but i also like the broader powerband this has for autox

In other news, whats with the fully built engine? :8

Re: ihi rhb5 vs. t25
 

i bought a parts si del sol for $250 mainly for the engine/trans. it originally had 235k miles on it. ran mint. but i wasnt about to put it in w/o a rebuild...and since down the line when i get outta school i plan on getting a gt28r and finishing up the head. and the suspension with PIC selects or moton shocks. i figured id take care of the bottom end now, since that can stay in when i finish the head.

anyways i see what ur sayin about the instant boost, and coming outta the corners and it possibly being difficult to avoid wheel spin.

so in your opinion on the two turbos ive mentioned, whats the better? the t25 id be getting for $40 in very good cond. while my rhb5 needs some work.(has oil in compressor housing, and the compressor fins have made contact with the housing.

Re: ihi rhb5 vs. t25
 

RHB5 is small and it will take some work to upgrade it later... The T25 would work but I think a 14B is a little better if you were going that route. I just went with the T3 because there are a ton of options out there that will just bolt on w/out having to change anything

Re: ihi rhb5 vs. t25
 

He's autocrossing not road racing.

Either one would probably work good. What RHB5 and T25 are we talking about here? Give us some specs.

Re: ihi rhb5 vs. t25
 

the t25 is from a 2g tsi awd A/T

the rhb5 idk whats its from. i think its from a t-bird..
when i googled the trubo it came up with something talking about the rhb5
exhaust housing says: 45t-1 7h31 52 20-r
compressor housing says: warner-ishi ihi turbo

Re: ihi rhb5 vs. t25
 

so close the choose is whatever one is cheaper

Re: ihi rhb5 vs. t25
 

I say the T25 since you can if you want to upgrade later on to a 14B or 16G it wouldn't be difficult or have to make a new manifold. I'd only take the IHI if it was free cause those are cheap in the first place cause paying for a rebuild on that isn't worth for what you would get out of. I had a RHB5 out of a subaru loyale on my 2nd kit and I enjoyed it cause it drove like stock as it spooled instantly and couldn't even tell when it spooled cause it came in so smooth. If I built another civic I'd go with that same setup.