Hey guys, this topic has been covered slightly with large frame T4's (gt35r and larger) But I want some input on a small frame T4 (not sure if that is a contradiction or not) it has a 62mm wheel with 2 and 3/8 inducer on both turbine side and compressor side. It is an IHI RHC7 turbo off some hitatchi deisel motor I think.. In any case i got it brand new at an auction and now want to use it on my mildly built b18c1. Specs are as follows:
81.5mm
CP pistons (10:8.1) with b16 head
Eagle rods, acl bearings
GSR cams, b16a head stock valves, springs and retainers
RHC7 turbo, T4
PTE 1000cc
big intercooler, 2.5 charge piping, ect.
Tuning on Chrome, Evans, looking for 350 wheel on street.

Now ive done my research as much as i can on this turbo, not a whole lot out there, spool time on a 7mgte Supra was just a hair over 4k rpm for full 26psi boost, so im thinking at least 5k or so on my GSR.

Here is the question, we all know a ramhorn is going to flow better, better top end power...ect, But im thinking i can cut down on spool time a little with a log mani, and save myself a good bit of cash condsidering all im looking for is 350-400whp. What are any potential downfalls in this thinking, from a tuning perspective, as well as anything else you guys can come up with. Also, please dont just say, sell that turbo and get a smaller 57 trim, ect ect, i want real thinking, technical perspective on this setup.
Thanks a lot in advance.
heres a link to the turbo.

http://www.hondamarketplace.com/show....php?t=2444606

 

24 views, nothing huh? up for more info.

 

My advice is that is your going to use that turbo don't run a log manifold. One of my old setups I had a very similar setup that you have listed and ran a log manifold. When I switched to a equal length tube manifold I could not believe the improvement in spool, power etc. Everything was better. I would recommend just save up a little more money and get a tube header...well worth the investment.

 

Yeah, i agree im hurting myself here, but we are all feeling the current economic crisis. If you dont mind me asking what was the size of your turbo? This turbo is clearly smaller than a GT35r, and is damn close to being identical to an SC61... Now yes i know it is a T4, but the physical size of the wheel is really not that big.... You said you saw faster spool? I was under the impression ramhorns, were slightly slower in spool time compared to a Log style??

 

I think will be better if u will make a custom log manifold such as front mount turbo manifold ( race one) but with the flange turned 90°, so u can mount ur turbo like on the log.
If u are running a log u will spool faster around 3.5 4.0k but top end power will miss a little...
You can use a log with a high volume air turbos, that pushes a good amount of air also at low rpm and pushes motor up fast.
You can add also vtec controllers and use vtec lobe cam at 3k, and this will make u happy....
Personally i run a ramhorn on a b16a2 with ptturbo sc61 that begins spooling at 4.5- 5k till 9.5k.
If u will make a twin-scroll flange ur happiness wil be more...

 

It might have just been me but I saw about 200 rpm difference between the two manifolds, my log mani was utter crap though. And for the top end...forget about it I picked up a TON of power.

 

Yeah, obviously the ram is going to have condsiderable gains in the top end, im a bit torn here, but thanks for the input, it has been quite helpful. wat size was your turbo?>

 

I was running a pt67 turbo...yes I know I was embarrassed to be running it on a log mani...just didn't have the money for a tube mani and needed to get the car up and running.

 

I was running GT4067 on Rev Hard log manifold and I made 650WHP@23 psi. I love log manifolds.

 

why not get a shorty from love fab or someone on here to make you something a little better then a log

 

wow 650, impressive, If im not mistaken i think matt keller use to run a inline pro log on his setup. And a SHorty mani is still like 400 new, i think im going to try a log see what happens, tuning is more important to me than the manifold. thanks guys.

 

jeff evans made 900whp in the crx with a inline pro log

 

inlinepro t4 log is the best for this scenario

 

thanks for all the replys guys, im seriously looking into an inline pro setup, well see what happens.

 

Inline pro is not a "Log"
It's a cast manifold with somewhat of a collector built into it. I highly doubt a regular log with exhaust gases from cylinders 1 and 4 firing at eachother will make 900hp.

 

Mister OP. If I were you trying to build one on a budget I could really care less if a ramhorn made more power at a given psi over a log manifold. If you want 350-400 whp you can get that out of a log/RHC7 combo, but yes the boost will have to be turned up a couple more pounds than if you had a ramhorn. At the end of the day 400 whp is 400 whp and while there's a bit of difference between the two manifold's powerbands you're ahead of the game.

One of my friends campaigned a 404 whp log manifold CRX a few years back, he was running 11.7-11.9's with some sweet 2.1-2.2 60' times. It was an old cobbled together bucket that needed a cage, but it was also a really fun car.



That's goddamn right.

Some of you guys are downright embarrassing talking about VTEC controllers and calling individual runner castings log manifolds.

 

Thankyou sir for the response, you are absolutely correct with that. Reminds me of an old saying "Function over fashion" certiantly this has to qualify.