Hello All

I am an owner of a MY93 WRX with following mods

HKS Air intake system
HKS exhuast system, with full decat etc
HKS 3 port Boost solenoid
HKS EVC Pro 4 Boost controller
HKS FMIC
HKS SSQV Dump Valve
HKS FCD Unit
HKS Boost Gauge
Uprated Fuel pump (new) Warbro
7D ECU
VF34 Turbo - Brand New
Uni-Chip recently mapped at Powerstation

I am running 1.1 Bar boost which is stable and car is running fine, mapped last week and on RR did this. It hits 1.1 bar at 3,300 in 4th gear.

Torque 250Lb -ft @ 5440 RPM 87 MPH
BHP 290 @ 6290 RPM 101 MPH



What I am wondering is why is this, should I be getting more torque down lower, from graph at 3600 rpm it is at 180LB Torque

Since I have had this car (4 months) I have felt that I was missing something down low rev range.....

Is this the choice of VF34 turbo being put on (after much consultation on here and Turbo suppliers was told VF34 would provide good spool up and low/mid power but from Dyno looks more at top end?) Is this a big turbo? If So What should I have fitted?

Could it be the 7D ECU fitted, what year of car is this from? UK/JDM?

The car runs absolutely fine and having a drive and a smile! with a few other Subaru's does perform rather well

Awaiting your advice/idea's

Cheers
Rob

P.S I have posted earlier with similar detail, but now have dyno and more info!

 

The VF34 is a rollerbearing turbo so your not going to get much better
Your pickup will be down to how the car is mapped though, if you have too much torque low down then you could compromise the reliability of your gearbox (as 5speed boxes are not the strongest in the world) where as in comparison, ive a VF36 rollerbearing turbo and i produce 250lbs of torque at 3000rpm (standard MY03 Spec C) but ive a stronger box and different engine than you have.
Your car should be mapped for efficiency rather than unreliability.

Tony

 

trebor69,
i was looking into getting the vf34. where did u get it from and how much did it skin you, if you don't mind me asking?
also how do you find it compared to your old turbo? have read about your worries but do you see any noticable difference?

cheers

andy

 

Hello Andy

I went from 275BHP to 290 BHP with this turbo fitted, the old turbo was a IHI RHF5 Type turbo fiited but had no markings on it, currently at Turbo Technics for Overhaul and tell me what it is, Prolly a VF28. But was poorly!

I got it from Midland Turbo for 695 inc V.A.T and Next day delivery, So very cheap, Brand new unit as well.

__________________________________________________ ______________

 

VF34 is fitted to STi spec C and runs 310hp standard(2.0ltr).
Has P18 housing and rated 350+hp.VF35 has P15 housing for more down low and quicker spool up .
These are the turbos I had TD04L>VF23>avo450hp>TD04L>VF34.Had the VF34 installed last week and seems pretty good.
1.15bar at 3100rpm 4th gear and around 350hp with a very conservative tuning.
I run M48pro(motec),fmi,fuel mods,3" from turbo back,pod filter.

 

Trebor, I would have thought that with the spec you are running you should be seeing another 50bhp adn 50lb/ft on top of your figures, still on a fairly conservative map. Also your torque seems to be coming in quite late. For comapriso, I am running a MY94 WRX, PACE FMIC, TD05 turbo, Blitz induction kit, 550 injectors, full scoobysport exhaust, and a remapped standard ECU and I get 325-330 bhp and 300lb/ft on ordibary unleaded, peak torque at 4050rpm and peak boost of 1.1 bar. Oh and before I fitted the FMIC and large injectors I was getting 294bhp and 275lb/ft.

 

Thats what I thought Stuart

Tis very wierd....

Wondering If:

Upgrade to Z4 ECU may help?
Is exhaust a bit blocked?
Could a more aggresive map help, It was mapped as said few weeks ago at PS after Uni-chip being fitted... This torque characteristic was there before turbo upgrade and uni-chip and remap done......
What effect would lower compression pistons make to a car??

Hope I can get to bottom of this wierd characteristic...

Cheers
Rob

 

Tony - I can't believe that 250lbft at whatever RPM would be compromising a standard gearbox. I've got ~260lbft at ~2800rpm - similar to several others with a well sorted new age TD04 set-up. However, as I've never seen over 272lbft on the rollers, I'm still short of the 330lbft ish that normally starts really caning the standard 5 speed boxes. (for reference, I'm tallking PE figures here rather than e.g. Powerstation)

Granted, drive harshly and less torque can kill a box, and your 6 speed box will be a lot stronger, and I have no doubt that you have a lot more than 250lbft at slightly higher revs.

Doesn't add much to the turbo debate, but I don't believe that the car should be mapped to only produce torque at high revs to protect the gearbox. High torque/high revs isn't noticeably more friendly on gearboxes that the same torque at lower revs, anyway, is it?

 

Hello Again

Has anybody got any Dyno's they can post up for me to compare torque curves.

From ones I have seen before on other turbo'd cars.. not subaru, the torque curve is quite flat, where as mine is a steady 45 degree gradient.....

When driving, you get the kick in the **** about 4,500 rpm... thats when the car feels like its pulling like mad.....

The turbo hits 1.1 bar pressure by 3,400 rpm in 3rd and 3,300 in 4th and 32,00 in 5th but the kick comes in much later.....

I am making something out of nothing here... Am I chasing a ghost!!!????

Hmmmmm...

 

changing the ECU shouldnt have an effect, as you control boost but EVC and all the other engine parameters will be adjusted by the uni-chip. So i would say that its down the the way the car has been mapped.
was it mapped on the road? or on a rolling road ? there is a difference!
it may also be a limiting factor of what the uni-chip can alter. it may not be enough from your standard map (in which case, changing ecu would have an effect -contradicting myself again! )

Steve

 

The car was mapped on the RR at Powerstation, I must say though that this characteristic has been with the car since I got it in October last year. I have fitted new Fuel pump, fuel filter, plugs etc and in last two weeks a Uni-Chip. All is tickety boo under bonnet, new samco turbo hosed, new turbo, So i would doub't very much it would be something to do with the mapping of car as it was like it before the Uni-chip and map!

I was wandering if timing belt could of been fitted tooth out, but then it wouldn't rev easily too 7k red line and it does that ok...Thinking too much about this maybe !!

If someone could in plain english tell me how the VF34 compares to TD04/5 etc and what characteristics it has.. that would be great... Please don't post one of them turbo charts, looks like chinese to me!!

Cheers Again
Rob

 

Hello Again

Right then....

Whats the possibilty of me having a blocked exhaust causing this late spool/torque problem I have....

It has a HKS decat straight though downpipe and hks rr silencer on

When I first got this car, i went to wales rally and somehow found myself on the track and messed about a bit, hit massive hole, bottomed out and damaged my silencer in rear of centre section (before the Rear box). A 3/4" hole was punched in around seam where it joins the pipe section. I took it of, filled hole up with weld and refitted...

I get no rattles or anyting from exhaust.

Anyone... Bueller Bueller

 

You say it hits 1.1 bar at 3300, is that when tested on the road, if so then I doubt, looking at the curve, that it hit that at 3300 on the rollers, torque curve is the wrong shape really. if it did then you may still not have a problem as PS rollers are considered to read lower than most, you could get a "second opinion" and take it to G Force, for a comparative bench mark Fangoria (Steve) is taking his car to Powerstation first then G Force on the 3rd April, he runs over 400 horses so a bit different but could give you some idea of the differences.

In otherwords the road reality may be totally different to the rolling road depression ...

bob

 

Hello Bob, I am going to take car back on road again and see, Spoke to Rich at Powerstaion, he seemed to think it was more 3,800 RPM!!

 

Which would go along way to producing the sort of curve you have.

bob

 

Dont get too hung up on the power numbers - you should ask yourself '' does my car feel fast on the road''

As an example on my older turbo (without headers and various mapping tweaks) I got 343 at Powerstation, 389 at Power Engineering and 403bhp at Well Lane - all these figures were within a couple of weeks - with very similar intercooler inlet temps................. so you can see the wide variety......... - I dont know whose is the most accurate as my car has not been bench dynoed to give a reliable indicator of power..............

Also it makes a difference which gear the car is run in - run in 5th gear you will get higher numbers than run in 4th gear. You should always just take the rollers as a benchmark figure...... I seem to go back to PS - others do not - must say something - but from my perspective I can go back to the days at PS when I only got 276bhp....recently I got 415bhp - it shows a picture overtime - pick a convenient RR and stick with it to see comparative changes - but DO NOT get too hung up on the numbers - its pub talk afterall!!!......... I know that if I get 415 on PS my car will be as fast as a car producing 450+ at Well Lane!!!!

 

Hello Fangoria

Its not the numbers I'm worried about, its the kick in **** that happens 4,500 - 5000 rpm. I know I should be getting a flatter torque curve most definately.......... and earlier...... I bought a Turbo 4WD for that low down grunt... My power band is 5,500 to 7k.......

BOB, you said "Which would go along way to producing the sort of curve you have."

What exactly do you mean???

Cheers

Rob

 

Boost makes torque, timing makes power (plus boost of course), good torque needs boost as low as possible, spooling 1.1 bar at 3800 rpm produces a late torque curve compared with 1.1 at 3300 rpm.

bob

 

BTW peak torque on early cars does come a fair bit later than the more recent examples, your boost controller should be capable of hauling it up early though.
bob

 

Hello Bob, thanks for coming back to me..

Right then, Have been out doing some power runs...

Tests done in 4th gear on flat starting at 1500 rpm

2,700 RPM 0.5 Bar hit

3,300 RPM 0.9 Bar hit

4,000 RPM 1.0 Bar hit

4,500 RPM 1.1 Bar hit and held

Between 2.7K and 4.5K I am getting a tcth tcth tcth air noise, I have new turbo hoses on and no leaks apparent anywhere. is this noise from the turbo compressor filling up the FMIC?

Once the car has hit 4,500RPM the above noise stops and at this point it is now going, up until 4,500rpm it is pulling but nothing amazing, I.E No kick, the kick... what there is of it is at 4,500RPM onwards.....

Also from 3,300 rpm .9 bar to 4,500 rpm 1.1 bar its like its struggling to get boost up and held...

Hope this extra info helps

Rob

 

Trebor

Are you going to be at Powerstation this weekend, if so, I have a VF34 on my car (mapped by Bob Rawle ) so we can see a comparison between the two.

How does it feel on the road?

 

Hello Scooby Drew

yes I am going to Powerstation this weekend, looking forawrd to meeting you all, and side reason also to talk to other peeps about this, So thanks for the offer m8! I'll deffo be comparing dyno's. I'll be in the Shiny Red one with Big 22B Spoiler L Reg.

On the road it is quick, Two other Scooby's had said so when we've stopped for a chat after some fun driving..... Maybe I am chasing nothing, but as I haven't driven another similair car to compare..... Just from Dyno BHP and more so Torque peaks are very late and a very 45 degree torque curve, not a flatish one!!

See you at weekend..

Cheers
Rob


Cheers
Rob

 

Trebor

I can give a drive for you and see if I can fathom out whats wrong.......... your getting boost very late on - which with the smallish turbo you have on should not be happening!!!

 

Cool, Starting to feel I'm not going mad, You going to Powerstaion on saturday????

You from Gloucester?

Cheers
Rob

 

From Bristol

I should be 1st on the rollers - then about 10.30 I need to be setting off to G force!! in Aylesbury!

 

Sorry to hijack the thread..

But does anyone have the web address for G-force please ?

 

Noise could be wastegate opening and closing rapidly- quite a few cars make that noise around spool up time. If it's open too much, that will stop the turbo spooling properly. At that stage, it may well be an issue with how your boost controller is set up? Worth getting someone cleverer than me to confirm that, anyway!

 

I was a wondering if that noise had something to do with, The boost controller does hold boost etc ok, but you never know!!

It is very much head scratching time with my car at mo..... spent 1.5K on it in last 3 months so getting it perfect if you understand, so clearing this one problem would make me so so happy :O)

Rob

 

Ok Chaps

Been out again doing some power runs to check my boost controller and have come up with some interesting results.

3rd Gear from 1,800 rpm
0.7 bar 3,000 RPM
1.1 Bar Held 4700 RPM

With wastgate hose removed, No boost limit control
0.7 Bar 3,000 RPM
1.1 Bar 3,600 RPM

4th Gear
0.7 bar 2900 RPM
1.1 Bar Held 4400 RPM

With wastgate hose removed, No boost limit control
0.7 Bar 2900 RPM
1.1 Bar 3300 RPM

5th Gear
0.7 bar 2800 RPM
1.1 Bar Held 4400 RPM
With wastgate hose removed, No boost limit control
0.7 Bar 2800 RPM
1.1 Bar 3000 RPM

With wastegate hose connected, it seems to struggle to get from .9 bar to 1.1 bar, I.E in 4th Gear takes from 0.7bar @3000 to 1.1Bar @4,400 thats 1400 rpm to get and extra .2 bar of pressure and hold it.

With wastegate hose removed I am getting same 0.7bar @ 3000 but it hits 1.1bar @3,300 , thats 1100 RPM less that with wastegate connected.

When testing with wastegate hose removed the boost just came on so quick to 1.1 and obviously flew past it, I set fuel cut to 1.4 to avoid massive damage here..

I have removed HKS 3 port solenoid and cleaned etc, no problems there, I have also reset Boost controller, done learning mode and tested again, same results (did this 3 times).

My thinking is that with a working boost controller I should really hit 1.1 bar as quick as having wastegate hose removed, but hold it as soon as it hits 1.1bar. it seems to me the build in boost is just too slow from .7 - 1.1 with boost control on.

Would it be worth while me getting on of the cermamic ball manual boost controllers, goes between manifold or turbo outlet and wastegate to check things out, do these manual devices work ok?

Please digest and let me have your comments

Cheers
Rob

P.S If I do need a new boost controller. I will have to fit box and new solenoid won't I? What are good value for money? Spent far too much allready.. Seems it could be that I didn't need a new turbo after all?