90 Turbo

iTrader: (3)

is this turbo between a 2554 and a 2560?

http://www.ebay.com/itm/New-Design-T...item3f0441846f

Please help I cant tell by the spec I am a total newb. Please help

messiahx

iTrader: (2)

It is around the same size as the 2560. The wheel sizes are the same but the housings are different. The compressor housing is smaller (has a smaller A/R) which I can't see having too much effect (please someone educate/correct me). The turbine housing has a larger A/R than a 2560 which will have the effect of shifting spool to a later RPM and letting the turbo breathe a little better up top.

So you can continue de-noobing: http://turbobygarrett.com/turbobygarrett/turbochargers

You will find turbo specifications here. Also, if you click the Turbo Tech link at the top of the page, you will find Garrett's excellent turbos for dummies guide. I've read it a few times.

mx594m

iTrader: (1)

the only drawback to the Garrett tutorials are the absence of adjustment for driveline HP loss, but that is a simple addition of 30hp to the flywheel numbers that they use

blaen99

iTrader: (6)

I think you mean subtraction. Although I've always heard a 15% reduction for a manual in going from crank to wheel, not a specific flat number.

mx594m

iTrader: (1)

addition -- when you are trying to determine turbo size for a target wheel horsepower, you need to add to the flywheel number the estimated driveline loss

do driveline losses change with the addition of horsepower, or do they remain constant?
I say more constant than as a percent

just my opinion, worth what you are paying for it

blaen99

iTrader: (6)

Ah, that would be one way of looking at it. Or in the above case, you subtract 15% to see if the number is what you want whp from the turbo. (100 crank hp minus 15 percent would mean 85whp, as an example)

You ding dang done made me google. And it's an absolutely fascinating subject that has an infinite amount of answers.

http://www.modified.com/tech/modp-10...s/viewall.html

Yeah, no definitive answer. The 15% rule of thumb I was taught may be completely full of crap, may not be.

mx594m

iTrader: (1)

what is driveline loss, energy dissipated by mechanical friction, acceleration [inerta], and rotating a mass [another form of friction], the amount of energy introduced into the system is not the determinant of the loss, but rotational speed is ==> therefore, there is a variable component to driveline loss, but it is rotrational speed related, so yes the answer is a lot of constant and a little variable; but in the final analysis, it is all an estimate [unless measured]

the purpose of my caution was to make adjustment to the calculations if using the Garrett site to select a turbo based on a target wheel HP [because the Garrett site example calculations only use flywheel HP] without the adjustment for driveline loss you will come up short

Braineack

iTrader: (62)

on the miata the drivetrain loss is around 25-30rwhp.


anyways, that turob has the same size compressor wheel as my 60mm 50 trim T3 wheel. It outputs like a 2554 with the max being around 30-35 lb/min. IT's running out of steam of my 1.6L around 240rwhp...which is fine because I never plan on going past that.

The turbine seems to be the same size as the T25 series...

so the turbo is techincally larger, and correctly labeld a T28, but since the compressor wheel itself is one of the smaller 60mm trims, it's not going to output as much topend as the 2560 would.

So to sum up, yes it's between a 2554 and 2560.

90 Turbo

iTrader: (3)

Perfect! you guys are the best!!!!!!!!!

90 Turbo

iTrader: (3)

how will this compare to a t3 50trim i have been seeing kicking *** in brains car?

Braineack

iTrader: (62)

like it said, it's the same exact compressor wheel, but the turbine is like half the size of mine.

mx594m

iTrader: (1)

only if there is a cheesehead inspector [i.e., government] and then there is less freedom

90 Turbo

iTrader: (3)

yeah the turbine wheel is but for some reason the a/r is .86 which means it will be slow to spool right?
That a/r seems way high like 2871 high.

Braineack

iTrader: (62)

a/r = area/radius

so it's just math.



the turbo you linked should perform just like the sr20 t25 with a bit more top end potentioal

90 Turbo

iTrader: (3)

Ok cool but the AR on your is like .63 according to garrett the turbine ar determines how fast it spools and I want as much boost down low as possible. how much difference you figure the .86 ar and smaller turbine is going to make on fast spooling? 500rpm? 1000Rpm.

90 Turbo

iTrader: (3)

Ok this might sound crazy but could I swap over the turbine housing from the 2554. So us the compresor and chra from this china turbo and the turbine from the 2554.

The turbine is 53mm in both and looking at them from the out side which is prob no indication for what is on the inside it looks identical.

I am sure this is a stupid idea I just thought I would ask. If my some chance it would work is it a good idea. The 2554 is letting a lot of oil thru and I would like to change it but cant afford the 2560/800$+ turbo for a little while. the cost of diypnp has tapped me out.

blaen99

iTrader: (6)

Just use the chinacharger dude.

blaen99

iTrader: (6)

Just to confirm - I'm "safe" running this compressor wheel on a stock block @ 14psi? It's not going to hit 300wtq or some crazy number that'll obviously bend stock rods, Brainy?

/Bump from the past, yo!

blaen99

iTrader: (6)

Old post, bumping for one reason, to give my 2c on the cxracing turbos:

The CXracing turbos are terrible. Ended up getting my hands on one, it hasn't even reached full boost (14-15psi) by 5000rpm. And yet, it's supposedly between a 2554 and 2560.

My old T25G was way, way better.

Braineack

iTrader: (62)

should be. it's only a 30 lb/min wheel. I run 13-15psi on my 1.6L and seeing about 240rwhp...so you'll be at the upper limits...possible more tq than you'd want to push...maybe keep it to 12psi until you can dyno.