Hello All

Having had my 93 WRX for a few months now and will be fitting a replacement turbo soon and this one is worn out and hits 1.1bar at 4,500 rpm in 3rd gear which I am told is quite late it has a IHI P1 VF28 turbo fitted at mo which sould spool ealier than most cos its small!!, It has left me wondering what is the normal rpm to hit max boost , obviously this changes depending on type of turbo and mod's etc.

If you could kindly post what turbo you have and what time you hit max boost and what boost (in bar!) that is for me to get some info and help me make my choice that would be great

Cheers

Rob

 

TDO5/06 20G 1.35 bar@3300rpm

 

In top gear: 1 bar at 2300 on TD04, 2900 on MD304, 2700 on TD05FE, 2950 on TD05/06-20G

Other turbos for guidance: 2600 on VF35, 2750 on VF34, 2700 for VF28/29

This is with a full decate exhaust and appropriate boost control.

Lower gears spool up later as their is less load and less time - about 200 RPM later for each gear below 5th typically.

 

Cheers all

Keep it coming

If you could say what you get in 3rd gear that would be good too!!

Also I have a HKS full decat system and HKS FMIC & dump valve and Boost controller.

Cheers

Rob

 

Rob,

Rather than a faulty turbo, I'd suggest your boost control is faulty. To see what is possible, try removing the hose connected to the wastegate and try again. Be careful though - as soon as you see 1 bar get off the gas....there'll be no boost control, and you may not have fuel cut enabled.

Richard

 

Hello Richard

So I take it you reckon that the wastage may be bypassing the gases so hence not spooling the turbo quickly....

I have an HKS EVC 4 PRO fitted, it does go to 1.1 bar and hold it.

SO when I take this hose of the wastegate actuator this keeps the wastegate shut so pushing all gases thorugh turbine blades but obivously as you said with no boost control.

Ok I shall pop out and try it then.....

I am pretty sure that the place i took it to get RR did this as they said they had bypassed all external controls and it still hit 1.1 bar in 3rd gear at 4,500 RPM.... But I am willing to try anything, They did say the compressor blades were worn....

Cheers

Rob

 

BTTT

Come on peeps, let me have some more figures to work on, seems my turbo was tired since I got my car, So hence not really sure what it should be like cos I ain't driven another one!!!

1.1 bar boost with good turbo and what rpm in each gear can I look forward too

Rob

 

Hello Again

Right then did some trial runs today starting at 2,000 rpm in each gear, here are the results I got, this is using Full throttle..

Taking reading when 1.1 bar reached.

2nd Gear 4,800 RPM
3rd Gear 3,900 RPM
4th Gear 3,600 RPM
5th Gear 3,300 RPM

I did above test again, this time removing hose from wastegate solenoid and this didn't alter results at all, So I take it my boost controller is working correctly.


Your comments regarding my results would be greatly appreciated.

Q. Should my turbo (being a quick spooling P1 type) be hitting 1.1 bar earlier than above. I have been told by mechanic that my compressor blades are worn.

Q. I have the opportunity to buy an as new VF34 for good price, would this be a good choice for good driveability I.E good spooling and low/mid power considering I have a HKS FMIC and Decat exhuast and complete HKS system inc downpipe...

I look forward to all you replies

Cheers

Rob

 

" did above test again, this time removing hose from wastegate solenoid and this didn't alter results at all, So I take it my boost controller is working correctly"

No - if removing the hose at the solenoid (assuming a 2 port solenoid; which of the 2 hoses?) makes no difference, then you removed the return to the inlet (rather than the one from the turbo compressor outlet), the solenoid is not working, or something else is wrong.

Try removing the hose from the wastegate

The solenoid is used by the ECU to bleed air away from the wastegate - allowing the boost to rise above the standard pressure of it (~7-10psi).

I can't conceive that your turbo would be faulty enough to slug the spool point so hard, and not self destruct by the time it finally got to 1.1 bar. It should be producing 1 bar in 4th latest by 3k5, and probably a lot earlier.

The vf34 is a little better than the 28, but I'd get your current problems properly diagnosed first - if it is boost control related, then the vf34 will suffer the same issue.

Richard

 

Hello Richard

On the test I did above, I did remove the hose from the wastegate unit on the turbo itself. I have a 3 port HKS solenoid fitted BTW.

One hose went to inlet manifold, one hose went to air intake body (before turbo) and the other hose went to the gold coloured solenoid on turbo itself, this is the hose i took off...

When I did this test if i kept my foot down it would jusy go off the scale in boost pressure then cut the fuel so i am pretty sure I took the correct hose off!!

The turbo is quite noisey, especially on slow down, It whines a bit like a jet engine on a plane slowing down... From my experience, turbo's should be quite quiet.....

The car does run fine, 285BHP when tested at Pstation which was then they said turbo was spooling very late and compressor blade were fairly worn.

I have no boost spikes, once at 1.1 bar it stays there fine.

I hope this sounds correct..

Cheers

Rob

 

TD05 1.15bar at 3000rpm..

JGM

 

Hi Rob, then I stand corrected Sounds like the bearing is gone then - shame it can't be ordered serparately for the VF series. It could be a snapped compressor blade too I guess - if so, I'll give you 50 quid for it

Richard

 

shouldn't be whining - sounds like turbo is TOAST am afraid!

 

16.8 psi (1.16 bar) @ 2900 rpms in 3rd gear w/ TD04- this is w/ full decatted, ecutek reflash.

The reflash comes w/ a 3/8" connector to allow boost achieve (otherwise only hits 15.5 psi (1.07 bar), the 3/8" connector also allows a slightly quicker spool. Some tuners are including a connector w/ a small bleed hole, they can run slightly lower WGDCs w/ this setup and still hit boost achieve (w/ quick spool).

Big Sky