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A/R on T67


Vaughany

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hI folks, i am hoping someone can help me with this, I know there maybe small differences but on a T67 what would be the standard exhaust housing A/R size based on a turbo rated to 650+ bhp.

 

My T67 is not making anywhere near the power it should and all aspects of the car have been looked over so there are no boost leaks, faulty wastegates etc. Supporting mods suggest I should be looking at 600+bhp at 1.4 bar but am way off this.

 

A uk specialist has had a look at the turbo and has said the A/R is way to small causing the turbo to choke. The guys with T67 making 600+bhp, what size is your A/R on the exhaust housing?

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What turbo do you have and what are your compressor and exducer specs?

 

Just as an example, the T67dbb BL turbo with a .68 (smallest) a/r on the exhaust can easily make over 600bhp without WI at 1.4bar (very much proven here in the UK ;) )

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Actually 600+ I think is more like, just about 600...570+ would be more like it to me.

 

The .68 is the smallest and the .84 next in line.

 

But, forget the numbers for a second...how does it feel? Does it feel like once spooled it slings you down the road at a million miles an hour? If it does...rely on the arse dyno :)

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Actually 600+ I think is more like, just about 600...570+ would be more like it to me.

 

The .68 is the smallest and the .84 next in line.

 

But, forget the numbers for a second...how does it feel? Does it feel like once spooled it slings you down the road at a million miles an hour? If it does...rely on the arse dyno :)

 

Hi Alex

 

I hav'ent drove it yet on boost, the mapper and builder have and they said its fast but definitely not right.

The engine has been built to take 2bar, the turbo is making no more power at 1.8bar than it is at 1.4bar, the sage continues

 

Hi Jamie

 

I trust the builder and mapper and I would hope the supplier would not/has not made an error.

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Which cams do you have?

 

If the builder/mapper says it's not right then fair enough. If you'd care to share by what margin then maybe we can work out the gravity of the situation...100HP 50HP 10HP??? Choking after 5000rpm, 6000, 7000....

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Cams could be choking it, boost could be leaking, timing might be off, maybe even the cams are a few degrees out? Without more data we can't really help - power outputs, boost curves, AFRs, what revs it keels over at... EGTs even - that'd show if the engine can't get the exhaust out fast enough.

 

-Ian

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Which cams do you have?

 

If the builder/mapper says it's not right then fair enough. If you'd care to share by what margin then maybe we can work out the gravity of the situation...100HP 50HP 10HP??? Choking after 5000rpm, 6000, 7000....

 

Hi Alex

 

The car is operating 272 cams intake and exhaust, veilside intake, hi stall torque converter. In terms of the build I would of expected 600bhp at 1.4bar based on other members cars achieving that on a similar or lesser spec.

 

Presently my car is making 520bhp at 1.4bar and will not increase above this at 1.8bar. All supporting electronics such as EBC have been checked with no problems. Everything is pointing to the turbo.

 

Presently i do not want to name the turbo but it is from a reputable dealer and do not want to start bad mouthing anyone until they share the exact spec of the turbo with me so I know who is at fault.

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Cams could be choking it, boost could be leaking, timing might be off, maybe even the cams are a few degrees out? Without more data we can't really help - power outputs, boost curves, AFRs, what revs it keels over at... EGTs even - that'd show if the engine can't get the exhaust out fast enough.

 

-Ian

 

Hi Ian

 

The info you have mentioned regarding possible causes, I will try and get this from the mapper and builder. The people involved in the build and mapping are very competent and well regarded. I am sure all the possible faults you mentioned have been checked and are correct.

 

Out of interest you run a T67 what is the exhaust housing size as you are making 600bhp.

 

Nic, the 520 is at the flywheel, I would be happy if it was at the wheels:)

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Nic, the 520 is at the flywheel, I would be happy if it was at the wheels:)

 

It does seem low in that case, I made more than that with a smaller GT35R, which is equivalent to a T61.

 

Do you know the actual rear wheel hp figure? Has the turbo been checked for damage?

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I have a T67DBB with the 0.68 A/R housing - 625bhp here. It does look very small when you look at it, but it does the job. You could always try the larger exhaust housing anyway - they are quite cheap IIRC. But I would definitely expect more from the 0.68 housing.

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Simon

 

My housing is 0.70 so larger than yours and I am making alot less power. This is puzzeling, maybe the compressor wheel on the inducer side is not T67.

 

I am hoping to have some answeres today either way, the car is going on a dyno at 2bar to see what the top end power is, if it does not make or get near to the quoted bhp from the manufacturer especially as all others areas have been exhausted, the problem has got to be the turbo.

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0.70 is not a T67..

PHR Stg2+ ? You can't compare 67vsPHRS2...you need to compare phr vs. phr.

 

No extra power at higher boost is odd. Does the extra boost change anything? Like seat of the pants wise or torque wise?

 

We know the builder is Leon...so no qualms there he knows his engines after many years.

 

It's almost like the Turbo isn't what you think it is. I'd get Leon to actually measure the compressor wheel etc and compare it against the diameter etc of a known good one....and that's another plan - find someone willing to let you borrow his "exact same" turbo to back to back test and measure them. PS if the turbo isn't what you think it is then I expect PHR just made a shipping error.

 

/EDIT

 

/Goes off to garage

 

PHR Stage 2+ Turbo Kit - T67 Turbo includes HKS 50mm stainless steel header, HKS GT 60mm external wastegate, 65mm 321 stainless steele Dump Tube

 

HKS 272 Cams Intake and outlet

HKS Adsjustable Cam Gears

HKS Type R BOV

Greddy Oil Catch Can

Veilside Intake with 100mm Throttle Body

Built Bottom End - Parts used rated to 1000bhp

PHR 150amps Racing Alternator

Battery Relocated to Boot

Various bits of Bling

 

Fuelling

RC 1200cc Fuel Injectors

Twin Walbro Fuel Pumps

Braided fuel lines

Aeromotive Fuel Pressure Regulator

 

Cooling

Greddy 4 Row Intercooler

Fluidyne Aluminium Radiator with twin electric fans

Mocal Oil Cooler

Mocal Transmission Cooler with electric fan

 

Transmission

4 speed Automatic Gear Box - Uprated and strengthened

3200 High Stall Torque Converter

 

Suspension and Handling

Tein Superstreet Coilovers with EDFC

Cusco Strut Brace

Race Logic Traction Control

 

Exhaust

3" Downpipe and midpipe

Blitz Nurspec R Stainless Steele Exhaust system

 

Electronics

Autronic ECU

Autronic CDI

Greddy Profec E01 Boost Controller

Greddy Oil Temp Gauge

Greddy Transmission Temp Gauge

AEM Air Fuel Ratio gauge

EGT Gauge to be fitted shortly

 

Ahh so I now know the mapper too..and he's definately M.A.D....I mean good ;)

 

Which Dyno is it?

Edited by Alex (see edit history)
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  • 3 weeks later...

Just an update guys, after a couple of weeks of diagnostics to eliminate any other possible issues and another mapping session by Mark Shead. The car was dynoed again yesterday and only made 512bhp at 2bar. This was exactly the same reading at 1.3bar and it seemed to be loosing performance as the boost was raised. The turbo was working at full capacity so obviously the turbo was only rayted for this type of power.

 

Everything has been eliminated and we are now certain that the manufacturer of the turbo sent the wrong turbo when it was ordered. I am been speaking to the provider for the last couple of weeks and he has been awaiting our results. I am hoping this issue will now be resolved asap so I can enjoy the car before the little summer we have left goes.

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Hi dandan

 

Here are some pictures of the turbo I have, the company do not stamp their turbos as they like to keep the spec under wraps. Turbo technics looked at the turbo and siad it would only be good for about 550bhp tops. We had it dynoed at 2 bar and only made 512bhp at the flywheel.

 

The specs of the turbo that I know are as follows

 

  • A/R 0.70
  • Compressor wheel - 67mm
  • Th egut said the turbo was a similar spec to a GT 35/62 and would make 550bhp tops

 

The specialists said the exhaust housing ws way to small and the turbo was choking - the sage continued, some one is at fault and it aint me, hopefully the parties involved will resolve this so i can get my car on the road.

DSC01269.JPG

DSC01271.JPG

DSC01273.JPG

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Do you have any dyno plots to post.

 

How does it spool, if its only generating that much power it should spool like crazy and have massive torque in the mid range. If not then something is deff wrong.

 

I have a 0.70a/r on my 60-1 turbo which produces 560hp at 1.4bar.

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Hi Wez

 

I dont have the graphs as they are still with the Leon. The torque figure was high. The charge temperatures were very high so the turbo was working flat out at 2bar.

 

The car made no more power at 2bar than it did at 1.4bar. This bhp fact, all the other possible causes being investigated and dismissed and the the specialists opinion have left us with no other option than the turbo is in correct.

 

As stated the manufacturer of this well know turbo provider states 660 - 680RWHP at 32psi. We are a million miles from this. The problem is and can now only be the turbo, we were suppied the wrong turbo.

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An easy check to drown out any doubters would be to drop a regular 0.68A/R T67 on there and see what she produces....that's a pretty well recognised, documented and proven turbo. Obviously someone would need to lend you one though...

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Yes mate but I think we have exhausted all options, the turbo provided is not producing the power, all other possible causes have been dismissed, no leaks or problems, car has been mapped by an expert.

 

The turbo has been run at 2 bar and the power is as stated, 180bhp off of the quoted figure. Simiular turbos to the one I should of got are making 580 - 600bhp at the flywheel at 1.4bar.

 

The turbo i have is making no where near that.

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