Help me choose the right turbo for 375ish whp
 

Hey guys its time to get rid of the stocker, it burns oil and just is about done.

I am running haltech with exhaust downpipe yada yada with 550/720.

Now my car is used for drifting/circuit use, I want good response (I like the stock response time) but more power around 375-400 ish. I dont drag race but on a completely gutted car that kind of power would be good for a flat 12 or 11's right?


I am looking at a used Greddy Turbo kit, I figure if I get that coupled with some 1600 secondaries I would be good.

I dont want a hybrid cause I have experienced boost creep on my ported internal wastegate.


If there is a better responding turbo setup that I can get for around 1500 than the greddy. let me know

Only having 550/720, Id say your best bet would be a BNR Stage 3 or 4 turbo. With the size they port the wastegate to (35mm) I doubt youd ever see boost creep. Itll be good for great power, and will still respond nearly like stock. With the right mods a Stage 4 would make your 350-400hp, but I dunno if you have enough injector to see that safely. Id go with at least 720/1000 maybe instead of 550/720

in my post I mentioned I have 550/720 which will become 720/1600 when I change turbos.

i agree with FCKIng BNR stage 4 is an incredible turbo and will easily get you to your hp needs BNRTurbos.com

I heard it was laggy. I dont wanna wait for 4500 rpms for my boost to kick in.

I considered BNR but I am a bit skeptical of internal wastegates, since mine is ported to an inch of its life and the inside is beveled as well I still had boost problems, which where found to be a torn wastegate diaphram.

I might consider the BNR.

But I bet the greddy will spool better and I can sell my Fujistubo downpipe to make some cash back.

I just have never seen anyone run the greddy kit

If your willing to spend the extra cash on a full single setup,

the greddy tdo6 20g Is a good option , will yield the 350-380 hp you want aprox at a bar ( 14.7 psi ) . with there 47mm Wastegate you wont suffer any boost creep.

also another good option is the journal bearing GT3574 Aspec is offering. Its a journal bearing version of the GT35R ( not exactly the same but similiar ) wich will yield very good results with good boost response.

BNR is a very good option, but its true the internal wastegates tend to boost creep . But ITs alot cheaper than going all out single. ( as you keep your IC piping , exhaust , manifold, etc ) .

what are the spool times on the stage 4?

I am stock turbo at the moment

what are the spool times on the stage 4?

I am stock port at the moment

I personally dont know the spool times on the stage 4, but from reading other members posts it was aprox in the 4000-4200 rpm range .

going from stock turbo to a stage 3 is quite the upgrade and you still have very good spool. 3400-4000.

Also spool is dependent on port job motor has and exhaust. ( and if full single upgrade , turbo manifold and sizing of turbine wheel and turbine housing , and tune ) . So what one car spools no necesarly will spool on another.

but for ruff guestimates I guess its good.

I agree.... BNR turbos are FcKINg great on and off the track. I have a stage 3 and im streetported. My turbo kicks in at about 3400. You can call BNR and talk to them personally i bet you can get a bit more direct help if you talk to him about your set up, the guys is pretty cool.

as do i havea bnr stage 3 with "stage 2" street port, but my car was is wayyyy untuned and running all gay, but it's quick untuned and wired all ghetto, can't imagine what it'll be like when we're done re-wiring the microtech

my stg 4 is on its way back to me brian is really nice and will help you out alot and plus you cant beat his prices

Not to discourage you from buying my greddy turbo kit or anything.. But Ill be completly honest and tell you, those BNR turbos sound fuckin awesome. I think I may go with the stage 4 instead of fuckin around with having a custm manifold made for my vert at the moment. My car has been down for over a month now. That guy Brian is also lots of help. I called him yesterday and we talked for about 20 minutes on all the different advantages and disadvantages of the stage 4 on my car. Overall im about 95% sure im going with the BNR stage 4 upgrade.Ill probably send it out monday. Then this summer Ill go with a full Aspec GT42R kit or something similar. Who knows, Maybe ill break theyre 402.7hp world record. :) haha.

Or if you still want. I have my single turbo setup still for sale. :)

I like your setup Frank, and I will probably get it after some research, seems it might be more responsive.

BNR turbos are laggy. Thats a fact everyone here needs to understand. Its a function of the interaction between a stock turbine and a larger diameter compressor. It takes more velocity to move mass. They will NOT out spool a stock turbo, but they WILL make peak boost in the 4k range.

Lag is also a function of your setup. You can do things with a Haltech that can aid in the spool of the turbo (lean ramp up area, timing, etc..).

If you want optimum spool, then a full single setup is what you HAVE to do.

^^^^ this guy knows what he is talking about, :)

There is an important relationship to consider between turbine vs comp sizes

Go with a full setup...no hybrids and you wont regret it

Actually, my original statement should read "it takes more energy to move more mass".

But most people on here would find the little extra lag worth the savings in just throwing a hybrid on and going.

so J-rat you think that greddy kit will reach my goals?

#1. You dont just throw a hybrid on and go

#2. Its not a LITTLE lag, its SIGNIFIGANT.

My car has had stock turbos, BNR turbos, and now a full single. I think I know what the differences are.

Dont get me wrong, Bryan makes a great turbo for those that dont want the hassle of going to an aftermarket manifold. Just dont get fooled into thinking they are not without some penalties.

Thats not a question thats so easily answered with out specs on the engine, turbo, manifold, intecooler, etc. Most notably, the turbo.

Greddy Exhaust manifold, Greddy Type R 47mm wastegate, and a IHI RHC7 turbo

on a 3"dual exhaust no cats no nothing.
Stock ported S4 T2 motor....will stay that way till it blows.

Greddy fmic

my stage 4 doesnt seem that laggy. its very responsive. but mine is a series 5, yours was series 4 correct?

Nope, mine was a series 5. Bryan didnt make Stage 4 turbos out of series 4 turbos. If he does now, thats news to me.

And do you have a comparison of boost levels versus rpm before and after the BNR?

Good point
When I talked to Brian over at BNR, he said the S5 turbos were more responsive at lower end then the S4 turbos. But the S4 turbos had more top end power.


Also.. Ive been looking around for more info and specs on this turbo. Seems a lot of supra guys use them. Well Here is some info I found. I hope it helps.

It has a 3" inlet and outlet. Undivided rear housing. T4 flange

compressor wheel
inducer=57.15mm exducer=81.91mm

57.15mm sq / 81.91mm sd = 49 trim

turbin wheel
exducer(inner edge)=62.61mm inducer =73.66

62.61mm sq / 73.66 mm sq = 72 trim

compressor housing
2.27 inches of area / 3.31 radius = .69 ar


turbin housing
2.16 inches of area / 1.285 radius = 1.68 ar


The only thing is 1.68 A/R on the turbine housing doesnt seem right. Im sure its a lot smaller then that. Im trying to find more info right now. Ill snap some more pics also. Let me know if this helps

I havent found out a whole lot about that IHI RCH7 except that it came with the older greddy kit, and its near impossible to get parts for. Looks like its maxed at about 375-400.

yep he does now i think maybe a year or two ago no.


no because my car ran like crap before i swaped the turbo over to the bnr, nothing related to the turbo itself just the car was crap.

im waiting for a new radiator to come in. as soon as it does, ill take a ride with my laptop and record the boost patterns off the microtech and post it on here.

Cool! That will work! If the numbers you record are good, then I will retract my statement.

Ive found 2 sites that offer rebuild kits and parts and service for the IHI RHC7 turbo..

I hope this helps.. I managed to find a compressor map for the IHI series of turbochargers a long with a few more sites for rebuilding and selling parts for this turbo. I have no idea how to read these things so someone else will have to chime in here.. :)

http://i56.photobucket.com/albums/g1...2/surgemap.jpg

Well thats what I meant, Still gotta have piggyback or stand alone, and other supporting mods, but its easier to just go hybrid than to piece together a manifold, turbo, wastegate, ect. For the cost and ease, Id say 4k rpm is a little lag IMO. Wasnt tryin to tell you wrong dude, just stating how I feel about the hybrid setup

Not a turbo I would personally mess with.

Why is that?

#1. Its not widely used.

#2. My garrett turbo has the latest and greatest technology to help boost more efficiently which garantees lower intake temps.

#3. Four or five repair shops nationwide is not what I consider blanket wide support.


Looks like the turbo flows about 69 pounds at 2.6 ish bar.

What turbo you all put on your cars is up to you, but I personally dont mess those types of turbos.

J-rat what are you (or will be) running for a turbo now after you topped the T-61?
just curious

So basically the only reason you wouldnt use it, is because its not a widely used turbo like your garrett?

Other then that.. How does it seem likes it flows? Would it meet the goals this guy is looking for? I have no idea how to read that compressor map so I wouldnt even be able to tell. Is flowing 69lbs at 2.6ish bar good?? Thanks J-rat.

The new GT4094R. Judging from your turbo choice, you are going a little harder then me. I am about to quit at the 550/600 hp mark.

No, its mainly because its a dated turbo. Again, this is a personal preference, but its not NEW. I dont really like the idea of slapping used turbos on my car. There isnt any way to tell what they have been through.


69 pounds would equate to about 600 horsepower on a rotary. 2.6 bar is about what.. 41 pounds or so? Doesnt seem like a very efficient turbo to me. Will it make 375 on a rotary? Probably, but thats about all you would get out of it unless you want to run crazy boost.

FYI, I got the numbers from my buddy Trevor. I cant read maps as good as him yet, but I am learning.

Thanks J-Rat.. the info is appreciated.. :)

damn this thread is becoming very informative.

I just have to think for a little bit before I decide to buy.

Haha.. yea.. Also now I know a lot more about the turbo as before I didnt have to much info on it.