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