14psi and 185kW

[merlin]

Did an interesting tune today, VR4 Legnum with an aftermarket intercooler and the red silicone plumbing.

Starting from stock, at 7psi and stock maps, gave 135kW.
Finished at 14psi tailing off to 12psi, produced a solid and reasonably flat 185kW.
From memory (frequently faulty) a stock Evo9 makes about the same, so this Leggy pulled pretty well.

The limiting factor turned out to be the intercooler, which basically enforced a boost limit of 14psi, after that the air must have been roasting. I am sure I've had better results with the HDi intercooler though.

 

[Scottie]

Nice number. I suspect these coolers as average (generic chinese). Did the car have an exhaust?

 

[unclepaulie]

thats very interesting

 

[qball]

My HDI intercooler fitted leggie pushed 18PSI from memory when you tunedit

 

[king_panther]

Wondering how much better a proper GReddy unit will let it breathe?

 

[smitty]

Wondering how much better a proper GReddy unit will let it breathe?

Merlin's more than welcome to come down and test mine out

 

[mookers]

There's a few of us interested in Melbourne actually. It's been on the cards for a bit but we're waiting for one of us to get his car on the road first.

 

[unclepaulie]

Mine has a greddy unit, come do mine again Dave lol

 

[merlin]

Yes Paul, ther are a couple of Brisbane cars I would like to re-visit.
Qball's HDi intercooler is a cracker, highly recomended.
What todays tune showed me (again) is just how effective a good intercooler is at producing good hp on the VR4.

 

[Nitephyre]

Great to see another stocko that was 135kw... it doesn't make me feel so bad now Also, it shows I've got potential

 

[Guest]

Do you know what brand the cooler was?

 

[merlin]

I had a good look but could not see any lable/markings etc.
Certainly no HDi mark in the usual place and nothing on the front.
It looked fine, not dodgy or anything, so well made, just not as good on the job as some others.

I suppose though if we had pushed the boost on further, we would have found the other usual issues:
BOV and plug leads
So 14psi was a good final value to settle on.

 

[unclepaulie]

I think I know what cooler it is. The type of silicone is a giveway

 

[Guest]

Was it one that had built in brackets specifically to fit our car or did it just have the usual stubby threaded holes top & bottom?

 

[merlin]

ummm, dont exactly recolect.

 

[Danners]

I had a good look but could not see any lable/markings etc.
Certainly no HDi mark in the usual place and nothing on the front.
It looked fine, not dodgy or anything, so well made, just not as good on the job as some others.

I suppose though if we had pushed the boost on further, we would have found the other usual issues:
BOV and plug leads
So 14psi was a good final value to settle on.

Sorry to steer this in a slightly different direction... but I have most of the mods recommended (RPW front pipes, high flow cat, 3" cat back exhaust, Greddy cooler, Apexi AVCR boost controller, AEM wideband) but I have not changed the plug leads. I am actively following Naughtika's thread on COP setup, but if this is too expensive i'll probably go and replace my leads. What leads do people recommend?

I haven't put my car on the dyno yet, so no idea what power it's making. A mate and I street tuned it.

 

[Guest]

Plenty of other threads about leads Dan.

So Dave, how did you deduce that the cooler was limiting the boost? There's no way there could have been leaks in the system (all tested recently?) such as the hose joins, throttle shaft seals, injector seals? Simply fixing up all my leaks on my car added a few psi to the boost levels.

 

[TME_Steve]

I got 200kW with a stock cooler.... 13-14 psi from memory at power peak (about 6000RPM) but different dyno's (mine was hub for starters) etc but it sounds almost like the aftermarket cooler was no better than stock.

 

[merlin]

The intercooler under discussion was most certainly better than stock, but would not let me run the spark advance that some other intercoolers allow.
At 185kw those little turbos are pumping pretty hot air.
The car actually made 198kw at one point, but, due to the nature of the boost controller and its response, a lower value was finally settled on as it gave a flatter boost figure.
But yes, with suitable support plumbing (and coils/leads etc) the VR4 will make 200kw on the stock turbos.
Thats gotta be close to a sensible limit though.

 

[VR4 MAD]

OK Dave, sorry for the dumb questions that follow.............

To clarify then, this car you mention at the beginning of this thread is stock apart from an after market (Chinese?) intercooler and silicone intake pipe replacements, correct? No exhaust changes, no decat or other changes and still uses factory boost control?

And this setup was getting 135kW before you did your magic on the ECU right? And after was getting 185kW, both figures quoted are at the wheels I presume? Measure how? On either a rolling road or hub dyno? Which?

And that tuning/mapping of the ECU was the full extent of the mods you did to get that improvement?

If so............... WOW

Don't get me wrong, I'm only making sure I know what we are seeing here so we can compare any future mods we might do and see how we compare.......... A target to aim for if you will.

Excellent work by the way. Way to go...........

Cheers