I want 280-300 hp at 8-10 psi. What turbo to use?

[240dx]

I want 280-300 hp at 8-10 psi. What turbo to use? What would the the most efficient turbo size?

Internal or external wastegate?

Im thinking t3/t4 .48 a/r or .63 a/r?

[480sx]

Perfect world, get a 50 trim .48 ar with an external wastegate. Bigger the better, but for under 350 a 38mm will flow fine as long as your wastegate system is setup right.

[240dx]

Thank you sir

[WDRacing]

Perfect world, get a 50 trim .48 ar with an external wastegate. Bigger the better, but for under 350 a 38mm will flow fine as long as your wastegate system is setup right.

Probably the best turbo for the KA Unless you want more then 350, I'd use it everytime.

WD

[TwoFoutyEsEx]

Im been told that the .63 A/R would be better for the KA and I though the smaller .48 would be better \About half the garrett 48's I find are internally wastegated.Should I look for something with an external gate. I hear the internals are not as reliable?
Modified by TwoFoutyEsEx at 12:55 PM 6/19/2009

[JRex]

turbonetics makes a t3 .63 a/r with an external wastegate. Probably what I am going to be switching to actually.

[V8slayr]

I dont know why KA-T guys even consider the .48 housing. I run the .63 on my SR and make 18 psi by 4400 rpm w/ a 2.5" downpipe. And what kills me is one of the main statements made when debating SR vs. KA is the .4 liters of displacement, why not use that extra half a liter and spool a larger A/R housing. A KA should spool a 50 trim a bit quicker than my SR.

[WDRacing]

I dont know why KA-T guys even consider the .48 housing. I run the .63 on my SR and make 18 psi by 4400 rpm w/ a 2.5" downpipe. And what kills me is one of the main statements made when debating SR vs. KA is the .4 liters of displacement, why not use that extra half a liter and spool a larger A/R housing. A KA should spool a 50 trim a bit quicker than my SR.

Let me break it down for you then. The .48AR turbo will spool quite a bit quicker then the .63 It will also efficiently make 300whp very well. Creating more lag is never a good thing IMO.

What goal you're shooting for determines the trim of the turbo selected. At 18psi you should be making 400+whp. Thats a far cry from 300.

At 10 psi of boost the increase in power generated by the .63 vs the .48 will be very minimal. So all you've suceeded in doing is reducing your useable powerband by using a turbo bigger then what you actually need.

This has nothing to do with SR vs. KA.

WD

[virus77]

To add to that Id run an internal gate at these levels and save money/fabrication

[91white_ka]

gtir t28..........it's a beast

[480sx]

To add to what WD said, there is no perfect AR for every motor. You size the AR with your goals. Ideally, you want the smallest AR possible that maintains safe drive pressures. That way you spool faster with no negative effects when set up correctly.

This whole power issue is negligible, a bigger housing does effectively nothing to increase power. A larger housing can allow the turbine to flow more gas at higher HP levels, therefor giving it the potential to create more power. The whole turbine housing AR deal is really, really simple lol.

[V8slayr]

Ok, i didn't really realize that's how you guys look at it. I guess myself, and most SR guys shoot for higher HP numbers on stock internals so I'm always thinking about max HP. I also spin my SR to 8k so I have more of an incentive for a bigger A/R housing. If it were me doing a KA-T I think I would still go w/ the .63 to try and shift some of the powerband up top, from what I remember about my KA power drastically drops off after about 5500. I like learning new things though, so for those of you who do run the .48 on a KA, how is the powerband??? When do you make full boost? Does the turbo pull hard until redline???

[WDRacing]

No worries at all homie. I'm the same way you are. If 10 is good, 20 must be awsome!!! I was using a full T4 with a .81AR for a little while...lol. THAT was laggy

[240dx]

A lot Good info in this tread. Im just looking for a reliable street DD not a dyno monster. Too me it's all about the low end power with a quick spool time Thats where all the fun is.

50Trim .48A/R is on it's way.Thanks.

I have 440cc Denso injectors.Does anyone know their limits?
Modified by 240dx at 7:48 PM 6/29/2009

[mechpro]

i have a twin turbo 300zx with t3/t4 hybrids externalwastegated i swear by them for any horsepower.

[WDRacing]

Wow...she must be laggy. How's the clearance in there? I upgraded a buddies 300ZX over on Oki to a 2875R setup and it had noticeable lag. Then again of you're making 500+ whp then who cares right...

[koukiFC]

gtir t28..........it's a beast

2nd that. i made 273 on 12 psi off this turbo(with supporting mods and about 20 hrs of dyno time). it is still a t2 flange so it will limit it you in the future but if you dont want to go crazy later on it is a good choice imo.

[compression]

A lot Good info in this tread. Im just looking for a reliable street DD not a dyno monster. Too me it's all about the low end power with a quick spool time Thats where all the fun is.

50Trim .48A/R is on it's way.Thanks.

You have the exact same goals I am looking for in my future KA-T. Can you tell me exactly which turbo you ordered, from where, and what you paid for it?Oh, and if its internal or externally gated?(I am looking for internal gated....)Much appreciated, thanks!


Modified by compression at 6:16 AM 7/29/2009

[240dx]

I got my 50 trim .48 A/R of ebay out of all places.It was initially gated internaly but he welded it shut and thats what got my interested.I paid 280 Shipped USDIts a garrett air research with very little side shaft play.Im on a college budget so it works for me. my Ka is on the hoist getting a downpipe fabb'd and the FIC tuned.Should be done in about 1 week Ill let you know how it turns out

[neverlift]

<<<<loves the .48 housing, full spool by the time you can look at the gauge, 4th gear it will make 12psi at 2600ish rpm and hold till redline....Well maybe not 7200rpm but close enough..

I dont like lag, I was concerned going to a t3, but my little garrett airsearch is awesome and cost me 40 bux. one day I'll add the bigger wheel I have from a z31 on the comp side but I dont see a need, 12psi is way better on a t3 flange IMHO, 12 on an sr t25 was lame in comparison to 7 from the current t3. ANd 12 is another whole ballgame...

[compression]

Thanks for the info.so....T3/T4 with a 50 trim compressor wheel and .48 A/R compressor housing.

I am having trouble finding this internally gated, any leads?Think ball-bearing is necessary?

A full report of how you like it would be good. Of course, i suppose that does depend on the tune. A s***ty tune can make any car miserable to drive... Hopefully thats not your case!

[WDRacing]

Here's the turbo I'll be using next.

Not a bad deal @ $450 with the internal gate.

[Crazyirish]

Here's the turbo I'll be using next.

Not a bad deal @ $450 with the internal gate.

Looks like a good price, but what's up with the turbine outlet? Wouldn't you be better off using a completely open 5 bolt output (like the sr) It seems like the wastegate would have a hard time getting any decent exhaust flow.

[WDRacing]

Um, if you can find a bolt on dump you can use it...if not This will work fine and it's affordable.

[rn240sx]

<<<<loves the .48 housing, full spool by the time you can look at the gauge, 4th gear it will make 12psi at 2600ish rpm and hold till redline....Well maybe not 7200rpm but close enough.. I dont like lag

i loved my 48 housing for a while until i started running with the big block v8's with nos on the interstate.... Thats when u find out ur 48 housing isnt capable of building more power as u get up top... SURE it holds 18 psi all the way to redline in 4th gear, but it aint pulling any harder... so i went to a 63, lost my ultra fast spool, gained some lag but FOUND some power up top And i prob wont ever give up that top end power for low end torque...