William's Dyno Results

[bradc]

william, what sort of power are you seeing now? I remember you were only at 140kw last time?

[william]

william, what sort of power are you seeing now? I remember you were only at 140kw last time?

Hi Brad

I am getting 166kw @12 psi. I will put up the dyno graph when I get back home tonight. As I said, the boost curve is very flat, much the same as it was before, just higher. Although the gain was only 18kw the car feels quite a bit more peppy because of the meaty boost curve.

[bradc]

thats good william, I look forward to seeing your graph

[Kenneth]

Hi Brad

I am getting 166kw @12 psi. I will put up the dyno graph when I get back home tonight. As I said, the boost curve is very flat, much the same as it was before, just higher. Although the gain was only 18kw the car feels quite a bit more peppy because of the meaty boost curve.

Hi William,

The biggest thing is the extra torque. With the VR-4 It can be difficult to get big numbers due to the way the turbos run out. You need to free up the intake and exaust big time.

But you can still get the torque down low, which is whats fun :)

It looked to me like your boost solenoid wasnt doing its job, or was blocked... When running without mine hooked up I have the same boost curve you had... flat at 8psi.

Still, 12psi is a good amount. Should be reliable as at 166kW :)

[william]

To be honest, Ken, I expected a bit more. As you know I also have a 3inch turbo back exhaust, Greddy front mount and a K&N pan filter in the stock airbox. The diagnostic check at Auckland motors did not show up any problems. Torque Performance did pick up a leak in the intake plumbing wich could explain the 8psi max boost before the boost controller was installed. Still, the car is definately quite a bit livelier and the low down torque good for towing my boat (1700kg)!

[mpau009]

To be honest, Ken, I expected a bit more. As you know I also have a 3inch turbo back exhaust, Greddy front mount and a K&N pan filter in the stock airbox. The diagnostic check at Auckland motors did not show up any problems.

Something does sound a bit suspect to me:thinking: If i could get 161Kw with just a pod and around 12 psi, i would expect more from the exhaust alone.. (M_B_N??) Have the compression ratios been tested? I thought it was quite a new car, so maybe there is something else not working right. I guess they would have checked the A/F ratio at torque performance, but maybe a poor spark or something?

[Kenneth]

Something does sound a bit suspect to me:thinking: If i could get 161Kw with just a pod and around 12 psi, i would expect more from the exhaust alone.. (M_B_N??) Have the compression ratios been tested? I thought it was quite a new car, so maybe there is something else not working right. I guess they would have checked the A/F ratio at torque performance, but maybe a poor spark or something?

You both got around the same power with around the same boost... Whats odd about that?

In a turbo vehicle, a bigger exaust does one thing (as always, all else being equal): Increase the pressure differential between sides of the turbine.

The bigger the pressure differential, the faster the gas passes through the turbine and the faster the turbo spools up.

It also means that at high load, the exaust gas escapes faster from the exaust and does not back up on the outlet of the turbine, which in turn slows the speed in which the gass passes through the turbine, decreasing performance of the turbo. (and the engine, as exaust gasses have to fight to get free of the engine)

With the VR-4, the exaust wont make such a huge difference up top because the turbos are just about run out, and you will need to free up the intake to take advantage of the extra exaust flow.

We have pretty much determined that on like vehicles, its the boost pressure that determines the power output. And this is again borne out by these results :)

[william]

I cannot agree more with you Ken. If you want more power, increase the boost. The non modified cars that made good power at the first dyno run all had boost spikes resulting in a good reading, although the good power was only during the narrow boost spike "window". My car is a 2000 model, has done 85000K , and as I said, all the diagnostic checks are OK.

[bradc]

william, 166kw is nothing bad at all. What was your AFR at max power?

[mpau009]

I guess that makes sense. I just thought that if there was less restriction, and colder air (you would hope) that more flow would mean more power even at the same PSI

ie: 12psi through a 2.5" pipe versus 3"

but i see what you mean about the intake restriction.:thinking:

[william]

william, 166kw is nothing bad at all. What was your AFR at max power?
Here are the before and after graphs

[Paul C]

sorry to jump in but was just interested to see how different the dyno plots are.There the same sort of car but the characteristics of the curves are different.

[Kenneth]

/Hijack

I am going for the Greddy on Flea-bay for £179 + p.p. Should be arriving within the next couple of days :evilgrin:

Sorry mate. Mmmm, boost controller.. hehe, good fun!



I guess that makes sense. I just thought that if there was less restriction, and colder air (you would hope) that more flow would mean more power even at the same PSI

ie: 12psi through a 2.5" pipe versus 3"

but i see what you mean about the intake restriction.:thinking:

Yes, what you say is true, but that is at the intake. You may get some efficiency gains at the intake, but nothing worth writing home about. You realy need to do some intake mods as well to see significant gains


I cannot agree more with you Ken. If you want more power, increase the boost. The non modified cars that made good power at the first dyno run all had boost spikes resulting in a good reading, although the good power was only during the narrow boost spike "window". My car is a 2000 model, has done 85000K , and as I said, all the diagnostic checks are OK.

Yes, and if you look at their graphs you will see they are getting max boost at the maximum power RPM (~5500) where you are dropping boost! Do you have a standard BOV? Seems there may be something wrong, as you should be able to hold more boost than that. I am holding ~12PSI at 5500RPM to your ~10PSI.. which is basicaly the difference in our power output.
If you have the standard BOV, try borrowing another one and see if it makes a difference. Richard (dickytim) had a pretty significant boost increase just by changing his BOV


sorry to jump in but was just interested to see how different the dyno plots are.There the same sort of car but the characteristics of the curves are different.


The curve shape reflects the boost characteristics, at standard boost levels the turbos are able to supply the same boost over most of the RPM range, but when you add a boost controller and demand more from the turbos, they start running out quicker, and thus the torque drops off and the BHP (or kW) curve flattens out.
My first dyno graphs looked like yours, and then after adding boost it looked like williams.
Imagine the figures we could push out if the turbos were just a bit bigger!

[william]

Yes, and if you look at their graphs you will see they are getting max boost at the maximum power RPM (~5500) where you are dropping boost! Do you have a standard BOV? Seems there may be something wrong, as you should be able to hold more boost than that. I am holding ~12PSI at 5500RPM to your ~10PSI.. which is basicaly the difference in our power output.
If you have the standard BOV, try borrowing another one and see if it makes a difference. Richard (dickytim) had a pretty significant boost increase just by changing his BOV


I have been thinking about changing the BOV. I can also wind up the boost controller a bit more as I have no problems with fuel cut. What about the actuators?

[Kenneth]

I have been thinking about changing the BOV. I can also wind up the boost controller a bit more as I have no problems with fuel cut. What about the actuators?

Well, if you want you can borrow mine for a bit (testing anyway... i assume you have a boost gauge so can monitor the boost?) as I will be running standard BOV for the next few weeks.

Actuators could be stuffed... but try BOV first, as they are a known weak point.

Dont wind up the boost until you know why you arnt holding boost, otherwise you will find that when you fix the problem you over boost and do some damage.

[colVR4]

I was having problems with the standard BOV. I changed it to a stainless steel replacement, still a recirc, and have had no problems since. I know that some members are running VTA BOVs but they can cause ultra-rich running.

However, my boost remains constant virtually all the way to redline with very little drop, so may be worth investing in one of those. Also, have heard that the EVO 8 BOV is a direct replacement.

[Kenneth]

I was having problems with the standard BOV. I changed it to a stainless steel replacement, still a recirc, and have had no problems since. I know that some members are running VTA BOVs but they can cause ultra-rich running.


I use VTA, it only spikes rich when lifting off the gas, no other time. I have checked this using my wideband sensor (which is acutally permenantly wired into the car)

Biggest issue with VTA is the idle problems. However somewhere I have given instructions on what I did to stop that... I think someone even tried it and it worked for them too :)

[william]

Thanks Ken and colVR4. I will replace the BOV then and guess I will see you at the next dyno day! Ken, thanks for the offer but I think I might as well go ahead and fit a good quality BOV and get it done with.

[Kenneth]

Thanks Ken and colVR4. I will replace the BOV then and guess I will see you at the next dyno day! Ken, thanks for the offer but I think I might as well go ahead and fit a good quality BOV and get it done with.

You saying my BOV is cheap and nasty? :inquisiti
/haz

Good idea though, the standard BOV is crap so you may as well change it anyway.

The benefit to testing with mine though, is that its already set up at around the correct spring pressure.

If I were to do things again, I would get a BOV with attached or integrated air filter.... then run it as loose as possible without stalling.

[william]

Thanks Ken. If yours is not cheap and nasty, why is it not in your car? !!:speechles Only joking. Where are you this weekend? Maybe I can come and pick it up some time.

[Kenneth]

Thanks Ken. If yours is not cheap and nasty, why is it not in your car? !!:speechles Only joking. Where are you this weekend? Maybe I can come and pick it up some time.

/haz
It IS in the car... it just wont be after this saturday. (at least for a week or so)

I will be in birkenhead this weekend :)

I'll warn you though, its a loud VTA bov... :P

[william]

PM me with your contact details and I will give you a call later. If you have to remove the BOV from your car I might as well just go ahead and get a new one. I will get a recirc so the wife will not start asking questions!! You know, all the money I spend on the car is because I am so frugal in not buying a new car and you can expect to have to spend some dosh on a second hand from time to time!! My dearest is still buying this!!