Compressure Surge Highflow Turbo

[blaikier33]

hello ive just got a nisstune ecu installed and tuned. ive had a highflow on the car for the past 5 months, and have had compressure surge problems from scratch. i thought we could make it better with a tune but no go

what it is doing is when i try and make booste bellow 3 grand in fifth, when ime over taking, it just goes into surge at about 5psi even on light throtle, it will do it in 4th at low rpm aswell.

if i go through the gears hard there is no problem.

i rang the place that did my turbo and they seem to think they put a t04b wheel in it, is that to big, would that cause this problem

its an r33 gtst s2

nistune

standard plumbback bov

14psi

[paulr33]

do some reading on compressor surge, understand what it is and this will give you the answer

the likely causes of compressor surge are mangled hiflows / mismatched specs like you mentioned

your kinda stuck with it i would say, did the place who did it offer any option to fix it or change the wheel

i mean if you've ordered a hiflow and been given a botched hiflow, what good is that? they should fix it or did you ask for that specific wheel ?

[blaikier33]

they said they would fix it at extra costs. they said they would put a smaller wheel on it. ive just got to find a nother housing so it can b machined to suet. does that sound rite

[paulr33]

yeah get them to fix it and make sure you check their policy if they botch it again

ie if they "fix" it and you pay a cost then you get it back and its the same surging, what is the next step and who pays?

[benl1981]

Probably a mismatach of wheel sizes (Comp/exhaust wheel) - i.e. too small exhaust wheel and/ore too large compressor wheel. Changing one of these should work to reduce the surge.

Though it's likely you/they will need to provide a new housing. Probably the easiest fix would be to put in a smaller compressor wheel, however this would mean you need a new housing as the one you have would be machined out too much.

Otherwise you get a bigger exhaust wheel (more lag though) that would mean they machine out more of your housing.

Sounds like they haven't done one before, so as paul said if you pay extra money you would want something in writing that they will rectify it for free.

And each time you pull it on and off (or pay a workshop) is an inconvenience to you.

Edited April 3, 2010 by benl1981

[blaikier33]

tell me about it i pull it of myself. i can get another turbo for 150 bucks is that a fairly good price. all i need is the exhaust housing

[Turbo Dave]

Mine did a similar thing to this when I had it, I got a VG30 exhaust housing fitted up and it went away, also pulled harder up top but was a little laggier.

[blaikier33]

that sounds good were would i find a vg30 exhaust housing.

[benl1981]

VG30 are hard to come by and they will be laggier due to the op6 larger housing (common to R34gtt and z32 3.0T VG30DET 300zx's).. $150 is a fair bit if you only need the housing (for an R33 turbo - for a vg30 you'll be lucky to get one for that price due to demand). Can you find a blown one for cheaper? Shouldnt be more than about $50 if the bearings are shot.

VG30 will make more power but you will lose response (probably about 300rpm, although it doesn't sound like much it will feel a bit more doughy, a really good tune may help this a bit). For 250rwkw and under R33 housing. For the extra 20rwkw go the R34 housing.

As turbo dave aid if you get the larger housing machined out to suit the exhaust wheel you have may solve your compressor surge issue.

Depends how much mucking around your willing to do and what sort of responsibility is the company taking on e.g. how much are they going to charge to swap wheels, machine out housing, balance etc?

[hypergear]

T04B wheel is a 16 fin 58T 71mm wheel is not really good for high flow purposes. and likely to surge as the exducer of it is too short for the inducer. But either way you shouldn't be getting surge at low RPMs.

also depends on the type of turbine wheel you got there. Do you have a photo of the turbo with booth wheels?

We have .63 and .82 turbine housings to suit OEM setups if needed.

[geraus]

blow of valvles making it surge or na?

[W0rp3D]

I have a vg30 high flow, has a t04b compressor wheel and the guy they built it was getting surge if it hit 15psi below 4000rpm so he back cut the exhaust wheel so it would hit 15 psi just on 4000rpm.

[blaikier33]

so what do guys think would b the best way to go.

smaller comp wheel, and new comp cover

or different exhaust housing.

would i lose power from either..

[lachlanw]

z31 300 zx . not z32

and vg30et not vg30det

Edited April 4, 2010 by lachlanw

[Adriano]

There is a blown vg30 turbo in for sale for $150 delivered

[KiwiRS4T]

I have been able to eliminate compressor surge with careful control of boost building with a Jaycar IEBC - you could possibly do it with another effective electronic boost controller.

[Dale FZ1]

  blaikier33 said:

so what do guys think would b the best way to go.

smaller comp wheel, and new comp cover

or different exhaust housing.

  hypergear said:

T04B wheel is a 16 fin 58T 71mm wheel is not really good for high flow purposes. and likely to surge as the exducer of it is too short for the inducer.

also depends on the type of turbine wheel you got there.

We have .63 and .82 turbine housings to suit OEM setups if needed.

Looks/sounds like a general mechanical mismatch between turbine and compressor, and then the whole unit to the engine. that 8 x 2 blade T04B impeller can push a lot of air very early, so a"tight" turbine that spools it quickly will lead to surge. But that comp is not overly efficient either, so going to a bigger A/R turbine might only partly achieve your goals for a performance application.

Firstly be sure the BOV is operating correctly.

Then, I'd say consult directly with Stao and get the turbocharger spec'd correctly if needed. They have a few different specs that should hit the target you want.

[blaikier33]

just pulled my intake pipe of to find a 16 blade comp wheel, 8 front and 8 sort of back a bit that aint rite is it.

obviously these flow heaps at low shaft speeds, what about when it is high reving.

thanks for the input to guys..

[Dale FZ1]

  blaikier33 said:

just pulled my intake pipe of to find a 16 blade comp wheel, 8 front and 8 sort of back a bit that aint rite is it.

obviously these flow heaps at low shaft speeds, what about when it is high reving.

As a 8 x 2 blade impeller, yep it's right for what it is (a TO4B). Is it "right" or "best" for a RB25 spec high flow? Check earlier comments by Stao.

You'll likely find that impeller is something used around a diesel application. Good flow capacity but the flow maps lay over to the right compared to (say) a high speed impeller like the 71mm GT35 as used on a GT-RS or GT2835R. Check and you'll see they run a 6 x 2 blade impeller.

The extra blades on yours give it that low end pumping ability, but it runs into choke and efficiency falls away as shaft speeds get up. Same thing you'll see happen with water pump impellers, jet ski impellers, and boat propellors.