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Hi guys,

Went for my first dyno tune yesterday & have to say I came home rather disappointed... After spending many months & more money than I care to think about doing up the car, power figures came in WELL below what I was expecting... :)

To give you a basic run-down, car is an R32 GTST with RB25DET & custom-loom, with following engine mods:

* K&N pod filter, boxed with CAI & solid 3" intake pipe to turbo

* GCG custom 500hp high-flow turbo (non-standard housings) (see below)

* Heat-wrapped eBay stainless-steel turbo-manifold (I know, I know, only for now...)

* Heat-wrapped 2.75" dump, 3" exhaust from front-pipe back, including 3" high-flow cat

* OE GTR FMIC with custom 3" piping

* 80mm throttle-body

* GReddy style plenum

* 800cc high-flowed OE injector

* Walbro 450 or 500hp fuel-pump (once again, I know... Don't want to start a ''Walbro is crap thread...)

* Haltech Platinum Pro plug-in ECU using MAP sensor

* OE RB25 boost solenoid controlled by ECU (see below)

Also has air/oil seperator, coolant header tank, remote oil-filter, etc but nothing else that should affect power... There could be some stuff that I've forgotten but if so will add in later.

Engine had compression test, leak-down, etc performed not long ago with good results.

Anyway, long story short, the car only made 178.7rwkw on 13 psi!

I see RB25s with standard turbo, injectors, ECU, AFM, etc that make that sort of power or more!

The turbo I am using is a GCG high-flow, but not the normal one that uses the standard housings. Is just slightly bigger than that...

When I questioned GCG about it, they told me it is a mixture of HKS & Garrett GT-series parts.

Am going to hit them up for more specific info during the week...

Anyway, definitely a steel-wheeled, ball-bearing turbo.

Seeming most RB25s using the standard-housing high-flows are making around 250kw I was obviously hoping for a little more than that.

The reason for the low boost is that using the OE RB25 boost solenoid we could not get boost above 13 psi, no matter what settings we used on the ECU. Tightened actuator pre-load too but that didn't do much.

I asked the tuner what he thought & he says the low boost is the reason for the lack in power. Says this is good power for the boost but starting to wonder about him... Also asked if he thought there could be any other restrictions but said it was too loud for exhaust restrictions & after looking at intake said that all looked to be good. Said to come back with a boost-tee & we should make 220ish but even that is much lower than what I hoped for...

One thing I did notice this morning is that a 5/8 hose had come off, between the IACV (or AACV?) & intercooler pipe.

As this obviously happened during tuning, am starting to wonder if it was leaking boost... Also being a MAP sensor am wondering if this will cause other probs?

Tuner also didn't use VCT as he said this was causing weird things to happen. Know that won't affect top-end power but makes me wonder more about this guy... Mid-range doesn't feel too bad at all but wondering if there's more to be had with VCT.

So apart from the hose coming off & possibly leaking boost, does anyone have any ideas what else could cause such low power?

Starting to wonder if tune is a problem but dont want to spend money on another one & get same results...

Will try & post up a dyno sheet, as well as pictures of the base fuel & ignition maps.

Sorry for the massive post :D

Trying to give the most info I can to help with diagnosis. (if anyone actually reads this whole thing...)

Any ideas or suggestions you may have are welcome.

Cheers,

Brett

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Sounds like you've got a few drama's to get to the bottom of. That power is about 30kw less than what I'd expect. If he's tuned it while that hose was off, it could mean it will run leaner now that you've reconnected it, so be careful.

An adjustable exhaust cam gear (retarded by 4 deg) will also be a good addition to add to your setup above.

Tuner doesn't know what he is talking about, take it somewhere else.

Also just because a car is still loud doesn't mean the cat can't be collapsed. When my cat collapsed my car was still loud, so first thing i would be doing is dropping the cat and running it again.

Edited by PM-R33

Thats definitely way too low in power.

Did you have some fixed price worked out with your tuner? I see this all to often people try and talk the tuner down to a set cost, so the tuner just gets things setup with time in mind. You need to get your tuner to work for you and find out the problems.

A good tuner should say look I can leave it as is for the amount quoted or I can start to troubleshoot but it will cost you extra.

Tuning and troubleshooting should not be skimped on, I think its the most important part of the process. Especially when you have spent considerable cash on parts etc.

Sounds like you've got a few drama's to get to the bottom of. That power is about 30kw less than what I'd expect. If he's tuned it while that hose was off, it could mean it will run leaner now that you've reconnected it, so be careful.

An adjustable exhaust cam gear (retarded by 4 deg) will also be a good addition to add to your setup above.

Yes, unfortunately... OK, good to know. I also thought that if the hose was off during tuning & I now re-connect it it may alter AFRs.

Also boost-solenoid is controlled by ECU so if its at about 80% (which I think it is) making 13psi & I fix a huge boost leak, starting to think boost may jump up quite drastically...

What would be the advantage of an adjustable cam-gear? More power at low revs or?

Go find a more "happy" dyno...

Not really after a "happy" dyno, although I may have made it sound that way. Have heard that dyno results can vary up to 30-40kw but even so if people are making 250kw+ with a smaller turbo & otherwise same mods as me shouldn't I be making at least 210kw?

Tuner doesn't know what he is talking about, take it somewhere else.

Also just because a car is still loud doesn't mean the cat can't be collapsed. When my cat collapsed my car was still loud, so first thing i would be doing is dropping the cat and running it again.

Sort of what I'm starting to think unfortunately.

OK, the cat is only a few years old & is a metallic-substrate high-flow item.

However, before the tune the car was running (although not driven) STUPIDLY rich (7ms pulse at idle) & I know this isn't good for cats.

Would this affect metal cats as much as ceramic ones?

As its map sensored, the hose wont effect AFR's, howevrer it could be the reason for not making over 13psi.

Can you explain why you think this? You may be correct, but I assumed if he tuned it with hose off & I put it back on the manifold would have more or less pressure, resulting in a different AFR, as well as the boost problem mentioned above...

Thats definitely way too low in power.

Did you have some fixed price worked out with your tuner? I see this all to often people try and talk the tuner down to a set cost, so the tuner just gets things setup with time in mind. You need to get your tuner to work for you and find out the problems.

A good tuner should say look I can leave it as is for the amount quoted or I can start to troubleshoot but it will cost you extra.

Tuning and troubleshooting should not be skimped on, I think its the most important part of the process. Especially when you have spent considerable cash on parts etc.

No, not really... He gave me an estimated price & time-frame & said it may be more if it took longer. He actually spent more time on it than quoted & charged me less as I think he knew I was unhappy with the boost level & power we reached.

As I say, the tuner seems quite happy with that power level for the amount of boost & seems to think more boost will fix the problem, giving me around 220kw's.

However I still think at this boost it should be making more power than 180kw's & with more boost should be well above 220...

Maybe I'm wrong & on another dyno at the moment it would pull 210 or something.

Was a dyno dynamics but I don't think it was in shoot-out mode...

As I said will try & get dyno results & pics of fuel & ignition maps up soon...

i would say he does not know how to tune a car.. and saying more boost will fix it.. pff run away from him.. just another boost junkie!!!!

Find a new tuner i would say with these mods and 13psi you should make around 225+ atw kw...

When we owned our car I fitted a twin dump pipe, full exhaust, high flow cat, knn filter in stock airbox and made 174.3atw kw from my GTT.

added front mount, ebc set at 11psi high boost, splitfires and good tune and made 213.7atw kw (ecu at limits about here for me)

So as you can see from my mods and power your tuner has no idea..

Good luck keep us informed :thumbsup:

P.S. Call Haltech and find out who they recommend to tune their ecu.

Edited by 99 GTT
i would say he does not know how to tune a car.. and saying more boost will fix it.. pff run away from him.. just another boost junkie!!!!

Find a new tuner i would say with these mods and 13psi you should make around 225+ atw kw...

When we owned our car I fitted a twin dump pipe, full exhaust, high flow cat, knn filter in stock airbox and made 174.3atw kw from my GTT.

added front mount, ebc set at 11psi high boost, splitfires and good tune and made 213.7atw kw (ecu at limits about here for me)

So as you can see from my mods and power your tuner has no idea..

Good luck keep us informed :thumbsup:

Depends when it makes 13psi of boost.. i dont think anyone should speak out until we see dyno graphs with A/F ration, boost ect..

If the turbo is to big for the application it can have negative effect on the power same with too small IMO

As its map sensored, the hose wont effect AFR's, howevrer it could be the reason for not making over 13psi.

True... I was thinking on an air flow metered car - I should have read the first post better!

What would be the advantage of an adjustable cam-gear? More power at low revs or?

Retarding the exhaust cam gear (by 4 deg) should give you more top end power, without any noticeable sacrifice in the bottom end. Given you may be getting the car re-tuned, I'd be installing an adjustable cam gear first.

As mentioned here is the dyno printout & some pictures of the base fuel & base ignition maps for people who know how to read them.

Sorry for the poor quality pictures. Had to take pictures of my computer screen with my phone...

If any different views of the map (or text pages, etc) will help anyone determine whether this is a bad tune, let me know & I'll pop them up.

post-35893-1267940691_thumb.jpg

Base fuel map:

post-35893-1267940132_thumb.jpg

post-35893-1267940332_thumb.jpg

Base ignition map:

post-35893-1267940448_thumb.jpg

post-35893-1267940570_thumb.jpg

Post up you dyno graph so we can see were its coming on and how hard or were not.

You dont have dodgy knock sensors ? I dont know about haltech and if that see's past them.

Knock sensors seem to be ok... Never threw up a code on standard ECU & engine & sensors have low km's on them...

Not sure how else I would know?

i would say he does not know how to tune a car.. and saying more boost will fix it.. pff run away from him.. just another boost junkie!!!!

Find a new tuner i would say with these mods and 13psi you should make around 225+ atw kw...

When we owned our car I fitted a twin dump pipe, full exhaust, high flow cat, knn filter in stock airbox and made 174.3atw kw from my GTT.

added front mount, ebc set at 11psi high boost, splitfires and good tune and made 213.7atw kw (ecu at limits about here for me)

So as you can see from my mods and power your tuner has no idea..

Good luck keep us informed :thumbsup:

P.S. Call Haltech and find out who they recommend to tune their ecu.

From what I know but, Neo engines came out with more power? Due to camshaft, ECU specs, etc? So would make more power with less mods than an R33 RB25... However I think you're correct. From reading dyno results, some people with just exhaust, cooler, upped boost, etc make more power than me!

Depends when it makes 13psi of boost.. i dont think anyone should speak out until we see dyno graphs with A/F ration, boost ect..

If the turbo is to big for the application it can have negative effect on the power same with too small IMO

Unfortunately dont have a graph with AFR's, etc. I think it was around 11.5:1 at full throttle nearing redline but thats about it...

Turbo shouldn't be too big. It is suggested by GCG for the RB25 & before this I had it on my RB20...

Even on the 20, with just turbo, intake, cooler, exhaust & upped boost it didn't feel much slower than this.

Definitely better with the tune, but with all other mods, bigger engine, etc I expected a huge hike in power...

Have I read it wrong or have you said you had a 5/8in boost leak?

Yes, when I looked this morning a 5/8' (16mm) hose which runs from the intercooler pipe had come off...

Not quite sure when it happened but I am assuming during tune

True... I was thinking on an air flow metered car - I should have read the first post better!

Retarding the exhaust cam gear (by 4 deg) should give you more top end power, without any noticeable sacrifice in the bottom end. Given you may be getting the car re-tuned, I'd be installing an adjustable cam gear first.

So with a MAP sensor AFR wont be affected? Something I may look into. Cheers mate!

Edited by wlspn
Not really after a "happy" dyno, although I may have made it sound that way. Have heard that dyno results can vary up to 30-40kw but even so if people are making 250kw+ with a smaller turbo & otherwise same mods as me shouldn't I be making at least 210kw?

Dyno's are a tuning tool... the numbers will only really mean somthing if you start with a baseline on the same dyno. Did you do a baseline run on the same dyno before you thew a bunch of parts at it?

Dyno's will vary by more that 30 or 40kw... think about the variations as percentage.

People really need to get into the basics of an engine... and understand how things work, before they go spending up big on mods.

Saying that, you have some work to do.... Basic fault finding!

J.

Yes, when I looked this morning a 5/8' (16mm) hose which runs from the intercooler pipe had come off...

Not quite sure when it happened but I am assuming during tune

In that case, fix it and go and retune the thing. Nothing else matters until you do this. That is lots of air that should be going into your engine that isn't.

Dyno's are a tuning tool... the numbers will only really mean somthing if you start with a baseline on the same dyno. Did you do a baseline run on the same dyno before you thew a bunch of parts at it?

Dyno's will vary by more that 30 or 40kw... think about the variations as percentage.

People really need to get into the basics of an engine... and understand how things work, before they go spending up big on mods.

Saying that, you have some work to do.... Basic fault finding!

J.

I understand this mate & am not just looking for the dyno to read 300kw or something, but as I say, even driving on the road, it doesn't feel that much quicker than my RB20 did with same turbo, exhaust, intercooler, pod filter & 13psi.

I didn't do a baseline run because the engine was swapped. While it was out a few mods were put onto it to make things easier later on.

Then the stock ECU couldn't handle all the mods so I got the Haltech, bigger injectors & here we are...

I do have an understanding of engines (I am a qualified motor-mechanic although I mainly work on automatic-transmissions & have little to nothing to do with tuning...)

In that case, fix it and go and retune the thing. Nothing else matters until you do this. That is lots of air that should be going into your engine that isn't.

Yes, this will be my first thing to look at. I am just wondering if someone who knows about ECU's & tuning can tell by looking at the fuel & ignition maps whether this is a good or bad tune. Obviously I don't want to fix the leak & go get it re-tuned from the same guy if someone who knows can tell me he hasn't tuned it right...

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