Best turbine for the KA

[WDRacing]

I see alot of people having problems with what turbo will best suit there needs. There are so many choices, ball bearing or not, T3/T4 or T04 series, internal or external wastegate.

I just figured I'd post the turbines that I would install on my car depending on what I would be doing with it. So here goes...

For an everyday street car, occasional trip down the 1/4, perhaps a street race(not that I would ever:D) I would want a turbine with very little lag yet able to handle atleast 15 psi without becoming a heat pump and suffering from compressor surge.

So I would choose a T3/T04Eseries. With an AR of .63 using a stg 3 turbine wheel and a 50 trim compressor. I would opt for a ball bearing turbo whenever funding allows.

My next step up would also be a T3/TO4E series. Accept I would use the 57 trim compressor. If your going for big boost you might want to consider going with an .82 AR for improved top end flow, but you'll suffer from slightly increased lag. This is the turbine my street car will most likely be using.

For a drag setup, I'm going to run either the above turbine, depending on how well it does on my daily driver, or a TO4R with an .81 AR and a 70-1 Compressor full ball bearing.

I'll always prefer external wastegates over internal.

WD

Edited for corrections...thx C-Kwik

[TurboKA37]

what about the t3/t04B in the nsport kit? what exactly is that turbo? a modified t04E?

[WDRacing]

Nsport is a TO4B...they don't list any trim. The TO4 exhaust housing will be better for yop end flow, but will increase lag quite a bit.

WD

[Xero]

that's good to know for buying a new turbo, but what about a junkyard kit? Like using a Z31 T3 or something, do you have any suggestions for junkyard turbos?

[red240ne]

I would like a T3/T4 with external wastegate and one loud *** blow off valve!! those are my only requests. i only care to make around 220-250whp. I WILL be buying your kit.

oh yea, i would want something along the lines of .63 AR as well. I don't care about have a 300+hp drag car.

[cow]

From the research I have done I think the T04b S-3 compressor trim is ideal for a drag car. The compressor's efficiency island falls squarely at the motor's torque peak. I don't know what A/R would be ideal, probably somewhere in the 80's.. depending on what's available I guess.

I was going to run a t04 but now I may swing more towards the hybrid (t3/t4) side since that should be enough for my needs. Although, those turbos seem to be a lot more expensive for some reason.

[SingleCamSam]

I was leaning towards the T3/T04E with the 60-1 compressor as well. Do any of you have experience with BB turbo's? I mean is it really worth the extra 5-800 bones on a street car? My plan is to run about 12psi, and i'm aiming for full boost somewhere between 3500 and 4 grand. This is for a 12v btw.

[DaveEEE]

Nsport T04B reaches full boost by 4k... With the mid to high end boost (f'n nuts on the street), the lag is a pleasure.

[WDRacing]

I don't buy junk yard turbo's...but alot of guys I know in Aussie are using the Z31 turbine and doing just fine. It's bigger then the T3 on the RB25 so I'm sure it'll work out. I could start getting prices for RB25 turbo's if you guys are really wanting to buy cheap junkyard turbo's. I think I can get them for about 200 bucks or so. Plus say 40 bucks for shipping. Let me know, maybe I'll make another thread.

WD

[Xero]

200? I found Z31 turbos from junkyards for as low as $75, though they were probably junk I'm gonna find mine somewhere off of http://www.car-part.com

[C-Kwik]

T04E's are not available with a 60-1 or 62-1 compressores. The 60-1 and 62-1 compressors are part of the T04B family of compressors. Either way, the 60-1 and 62-1 are designed to flow lots of air for a relatively low boost pressure. For the KA, it will either be in a very inefficient range, or possibly even experience surge. I mapped noth using a rough estimate for spool up of a T4 turbine. The 60-1 looks like it will be very close to surge. A T3 turbine will probaly cause it to surge.

As far as a T04B S-3, it's not a bad match, but it still doesn't match the efficiency of the T04E-50 trim. The S-3 has a max efficiency of 73% and is only available up to just abot 1 bar of boost. The T04E-50 has a peak efficiency of 78% and it is available at over 1.5 bar. And 76% efficiency is available well over 2 bar of boost.

A T4 turbine is not a bad match for the KA. Depends on teh trim of course. It will spool up slightly slower than a T3 turbine, but expect a better top end since it does not create as much backpressure to create the same amount of boost from the compressor. If I was looking for all out HP, the T4 would be my first choice. For good response the T3 will spool well, without sacrificing too much top end.

[:: orion ::]

I'm with C-kwik...

IMO, the ideal KA Turbo for really anywhere from 250-3450rwhp is a T3/T04E, 50-trim, stage III wheel, .63 A/R.

I run the same turbo, except I got the 57 trim, wish I would've bought the 50.

Jay (PSI240SX) made 412rwhp with the 57 trim...so it has the flow potential.

Later - Brian

[TurboKA37]

250-3450 rwhp on a KA???!!! i would really like to see 3450 rwhp on a KA. and if the T04B series turbochargers are not very good for the KA y does a quality kit like NSport use this turbo?

p.s. i know u meant 345 instead of 3450 rwhp .... i hope

[:: orion ::]

Yeah...I meant 250-350rwhp.

And the T04B isn't bad...just the T3/T04E is more efficient.

N-sport used the B for fitment - An On-center T4 doesn't have fitment issues with the RevHard manifold like a tangential turbine does.

But an N-sport kit with the T04B vs one with a T3/T4 (50-trim as listed above)...the hybrid WILL be more efficient and have better spool.

Later- Brian

[TurboKA37]

what is the actual physical difference between the T04B and T04E turbos?

[C-Kwik]

I'd say a T04B is used for cost. At 6-7 psi of boost, the difference is marginal as both turbos will be in the low 70% efficiency range. The T04B will achieve a mid 70% efficiency, so it's not a bad turbo depending on the boost you will be running. The T04E-50 shines because the 78% efficiency island exists over a very broad boost range. The 76% island is even broader.

As far as fitment, there is no difference between the T04B and T04E since the same turbine housing can be used.

As far as the physical differences between the B and E, the E uses a 1/4 inch larger compressor wheel(major diameter).

[SingleCamSam]

Quote » I would opt for a ball bearing turbo whenever funding allows[/quote]

How much quicker is the spool up on a BB turbo compared to a standard bearing turbo of the same app. size?

[C-Kwik]

Typically about 500 RPM. Not a whole lot, but enough. THe bigger benefit as far as I am concerned is the BB will make it easier for the exhaust gas to spin the turbine, further reducing backpressure since the wastegate can open sooner and let more air around the turbo. Frees up a few extra ponies.

[sil80drifter]

How good do the Z31 turboes work, and what is the lag/boost threshhold on them? I know that MKIII Supra T3's are incredibly laggy, their exhaust A/R's near 1, which is why they boost fully near 4k rpm on the supras (3 liter engine mind you), so I was wondering if the same goes for the Z31 turbo, or if it's a better spooling turbo. I.e: What are the z31 turbo specs? A/R? Compressor/turbine size? etc?

sil80

[WDRacing]

I love having C-Kwik around to plot turbine flow rates for me....heh. Good info...

WD

[C-Kwik]

heh. But it was actually the compressor I mapped. Unfortunately, I haven't found any turbine maps. I've seen efficiency graphs for the Garrett GT series turbines though. Not totally certain how to look at it yet though.

[WDRacing]

I used the word "turbine" meaning the turbo as an assembly. I know you plotted the CR side silly.

WD

[_dk]

I know that MKIII Supra T3's are incredibly laggy, their exhaust A/R's near 1

3g supra engines didn't use garrett turbos... they had a "ct26", which was also made by toyota if memory serves

[:: orion ::]

How good do the Z31 turboes work, and what is the lag/boost threshhold on them?

I.e: What are the z31 turbo specs? A/R? Compressor/turbine size? etc?

They work well for cheap $$$...

Compressor is a 60 trim (IIRC), 2.25" inlet and 2" outlet. A/R is .60...

Turbine is Stage I wheel, .63 A/R, internally gated.

Good 'til 14-15psi on the Z w/ a 3.0, so I'd say that's about the same for the 240SX.

Lag is almost non-existent - It boosts by 2500 even at 10psi on a friends S14.

Later - Brian

[encasemyheart]

3g supra engines didn't use garrett turbos... they had a "ct26", which was also made by toyota if memory serves

Yeah the CT26 is a Toyota turbo. It is used on the MKIII Supra and on the MKIII MR2 turbo. The only difference between them is the Supra's CT26 is not "Twin Entry" and is clocked diffrent then the MR2 turbo. Also the compressor is slightly larger in the Supra's CT26.

[KApwr]

I think in order to pick the right turbo for the job, you have to set your goals out first. How much boost do you plan to run, your hp goals, stock motor, built motor, street/strip?? Since a majority of us fall in stock motor/low->moderate boost, then the T3/T04E 50trim would be the best choice based on the efficiency maps and also real world experience. I have seen this turbo support anywhere from 200rwhp up to 500rwhp, so based on its flexibility, this turbo should be able to accomodate a majority of all KA-T users. This is not to say that you can't use other turbos like the Z31, T04B, 60-1, T70. These turbos will do just fine but are limited to the range that they accel in. For example, Z31 (smaller T25-T3 turbos) are limited to low, T04B-60-1 moderate to high, T70 high boost. The T3/T04E 50trim, stg 3 .63 A/R seems to be the "jack of all trades" when it comes to "the" turbo for KA-T apps since it does accomodate all boost levels well and lag is minimal. The T04E family is a newer wheel design than the T04B hence it's greater efficiencies. The newer GT series family should best the T04E family but I haven't been able to find a map yet but this is another alternative also. Happing boosting:D

[sil80drifter]

orion, thank you, that's all the info I needed. Btw, I know that different year Z31 (84-87 and 87-88) used different turboes. Were you talking about the 87-88 (watercooled) ones?

_dk, ur right, but the info I gave is partially correct nontheless; the MKIII turbos are laggy bastards.

KApwr, if the Z31 turbo can suport up to 15 psi (which I will assume is around 280whp on our cars), then it is more than enough for my purposes. If someone knows what power levels to expect out of it, and can correct me on this figure, please do, it's important that I know what the turbo can do.

I plan on an initial 200whp, and then AT MOST 300whp. That's it, that's as far as I'll go, and hopefully will be abel todo it on a stock block. I know it sounds extremely optimistic, but I will not just barge into 300whp, but slowly see what 200 is like, drive it for a while, seing what I can do to up the boost and avoid detonation (WD, I AM consideringalcohol injection as an alternative way to get there as well, but if I can do it without alcy, I'll be even happier). I really don't want (and can't right now) spend more than 200 dollars on a turbo, so I'll be goign with a used one, hopefully in good shape. This won't be as much of a race for high power, but a way to learn about turbocharging my car. An SAFC II, and larger injectors, log style manifold, along with some kind of intercooler about 3 gauges, and misc lines and piping (exhaust/IC piping/etc) is all I'll be needing for this project. I am hoping to get a Z31 turbo from a junkyard, and perhaps run it for at least 10k miles before i'll have to rebuild it. The idea behind this being a slow, gradual buildup, with inexpensive parts (all work done by me, including welding) which won't leave me bankrupt, but also won't be a waste fo time, because the expected results are more than satisfactory for me.

sil80

[:: orion ::]

orion, thank you, that's all the info I needed. Btw, I know that different year Z31 (84-87 and 87-88) used different turboes. Were you talking about the 87-88 (watercooled) ones?.

sil80 -

The '84-86 were T3s, and I think they switched to T25 in '87. Not sure about the switch to the smaller turbo...maybe it was only the '88-89s...???

But '84 was oil cooled, '85-86 water cooled IIRC. Again, this is from fuzzy memory...

Later - Brian

[sil80drifter]

http://www.nissaninfiniticlub....11631

my own question answered

sil80

[_dk]

_dk, ur right, but the info I gave is partially correct nontheless; the MKIII turbos are laggy bastards.

no argument there; i just didn't want anyone who came across this running out and buying one for a "good cheap drag turbo"- the flange on them has a unique bolt pattern.

encasemyheart: you missed one, it was also used on the celica all-trac/gt4