Power problem

As most of you will know I've had an issue getting my car over the 450bhp mark that it should easily do on this turbo (gt3071r .86ar) changed bits and bobs (piper vernier cam pulleys dialled in) 3 inch side exit so no restriction there, but have been told by a few people in the know that they believe my forged front mount is the issue as it has a 2.5 inch core which they believe is causing a restriction at these power levels (currently won't go past 412bhp at 1.85bar ) you can up the boost but the power won't go up) I was told to do a pressure test across the cooler which I finally got around to doing this weekend, I welded a nipple onto the inlet and one on the outlet and took it for a couple of quick pulls in third and 4th, it came back at around 0.1bar difference (which isn't what I was hoping for) my mate (who is very good with these sorts of things) is adamant it's still the forge 2.5 inch core causing the issue! Any way, what do you guys think? Is this this the issue? I'm fitting a new 3 inch cooler in the next couple of weeks and taking it back for mapping so will find out if it's that or not, my question is if it's not.....then what the f@ck is it! This has been pissing me off now for a very long time, I haven't gotten around to this sooner as you will all know I have been plagued with gear box issues, any way, any input would be great guys, I really want to get to the bottom of this now and sort it

Spec
Forged pistons
700cc injectors
Z32 maf
Ported standard manifold
Gt3071r .86 with the largest exhaust wheel they do
3inch side exit
Gems ecu
Tial 50mm blow off valve
Piper vernier pulleys dialled in
These are a few of the mods I think are worth mentioning

What duty cycle are the injectors running at at 412bhp
And you dont think its boost related not letting you go past 412 ... like wastegate ???

I couldn't tell you, the guy I took it to said it wasn't a fueling issue or a problem with the injectors, pretty sure waste gate wasn't an issue either

Bob had my car over 400 on a 2871r with forge front mount

I would of thought turbo is on the limit around 450bhp?

I have a gtx3071r but cant remember trim etc mine is running around 400/400, cant remember exact figure but due a trip back to Bobs very soon.  Will post the out come with spec, graph etc then.

GTi ARGHH wrote:I would of thought turbo is on the limit around 450bhp?

I have a gtx3071r but cant remember trim etc mine is running around 400/400, cant remember exact figure but due a trip back to Bobs very soon.  Will post the out come with spec, graph etc then.

There rated to 470 and I know of one that made 486 recently so the turbo isn't the problem, especially not at the power I'm at atm

PartyPete wrote:

GTi ARGHH wrote:I would of thought turbo is on the limit around 450bhp?

I have a gtx3071r but cant remember trim etc mine is running around 400/400, cant remember exact figure but due a trip back to Bobs very soon.  Will post the out come with spec, graph etc then.

There rated to 470 and I know of one that made 486 recently so the turbo isn't the problem, especially not at the power I'm at atm

Fair enough, but arent they all a bit over rated anyway? They used to claim 500-550 a few years ago (from my crappy memory) but thats probably not on our 2litre blocks?

Dodgy boost controller?
Solenoid?

Always thought the forge fmic was the mutts?
Maf, ecu, leak etc?

The turbo was looked at and measured to make sure it was 110%a 3071 which it is, and there more than capable of going past the power im currently stuck at so that's ruled out,maf's are capable of that power, if there was a leak of asume id have more problems than this (I.e missing) which it doesn't. When it was mapped there were no problems that were clearly visible, he said the intercooler looked like the problem due to how thin it is, I always thought they were supposed to be really good but again a few people have said going over 400hp there not brilliant....

What vac hose are you using? Is it to soft and collapsing or ballooning under high boost pressure maybe?
If you have been told fmic and piping needs to go bigger and thats being done soon. I wouldn't try looking for anything wrong until that's been ruled out.
Or be happy with the boost you already achieved you greedy cunt

As far as I know stu it's all pretty standard stuff? I just don't want to pay£250 again for another map and not get the figure I want once again, I've all ready chucked a grand at it just on maps trying to get the power up, and I want MORE POWER!!!

Have you tried cleaning out your intercooler, if it's flow that's a problem you may have a restriction in there from old oil etc. It's just when I bought mine I cleaned it and it was full of old shitty oil and kitchen wipes, which someone had used to blank it but forgotten to take out.

A bit out of topic, how come you have gems and still running a maf?

Toaster you may be right, But I'm going to fit a bigger cooler to be on the safe side, and Astra the gems is a very old ecu for group n rally's, the rule was it had to run maf to be able to compete,it has anti lag, I stupidly bought it in a rush. I will change it to a modern one in the future

When you guys talk power is that at the wheels or flywheel?

What's your turbine pressure at? Have you tried reducing boost and adding timing? What sort of ignition system are you using?

It's usually at the flywheel in the uk ducie, all I can tell you is it's at 1.85bar of boost, the ignition system is standard but again there known to be fine at that sort of power,its down to the guy who mapped it to check those sorts of things which I think he will have done, he's pretty well known over here for working on these cars so I'm sure it's something he would have considered.

Post up a graph. Id like to see boost and torque.
Who is going the mapping?

Like ducie mentions ignition timing can hold back lot of power and lot of tuners over cautious with ignition advance so lot of easy power held back .
assume all hp figures quoted are RR estimated flywheel .
Seen few 54C's make quite easy low to mid 400's with standard manifolds and various turbos so should be fine in that area but wouldn't hurt investigate.
Lot of people go nuts on intercooler core thickness but it actual core volume which heightxwidthxdepth that relates to volume, depth tends be one easiest increased due to layout/fitting hence why always gets the attention.
I would be surprised if a nornal bumper fitting front mount of sensible quality at 2.5" depth would be restricting you to current hp, I seen standard top mounts produce more than that and with decent charge temps when using water injection.
worth doing a pressure test right from turbo to pre cooler nipple and also to plenum inlet just to see full range of system pressures, sometimes an odd design pipe run can cause issues but even then can't see it holding you back drastically without being visually obvious, exhaust side issues more likely I would guess ...

Ducie wrote:When you guys talk power is that at the wheels or flywheel?

What's your turbine pressure at? Have you tried reducing boost and adding timing? What sort of ignition system are you using?

Mr B wrote:Like ducie mentions ignition timing can hold back lot of power and lot of tuners over cautious with ignition advance so lot of easy power held back .
Seen few 54C's make quite easy low to mid 400's with standard manifolds and various turbos so should be fine in that area but wouldn't hurt investigate.

I would be surprised if a nornal bumper fitting front mount of sensible quality at 2.5" depth would be restricting you to current hp, I seen standard top mounts produce more than that and with decent charge temps when using water injection.

As the men said above ^^^

at 1.85bar she should be making around 450-460bhp if everything is as it should be

Heres a few things you need to know though:

What torque is she running at 1.85 bar?

Can you post up the dyno graph?

What size pipe are you using from turbo outlet to ic and what size on return to plenum (this alone makes a big difference due to air flow and pressure changes)

Ignition advance on high load cells?

What are EGT's at on high boost if you cant get to ignition map?

Can you upload the ignition map?

It could be any number of issues causing the problem to be fair so you need to try break things down to determine what the issue may be but one thing i 'dont think' it is...........is the IC itself.

Dont get caught up in the power thing as BHP means very little, its the torque figure which is much more important. The most important thing of all though is how the power is delivered (drivability) throughout the rev range.
A well mapped 320 bhp car could literally run rings round a 420bhp car thats been poorly mapped with things not functioning as they should be.

Right, it's at approx 420ftlb torque. I will post the graphs up when I get home for you guys to have a look at. The pipe is of remember 2.5inch? It's the same size as the inlet manifold opening any way.
No idea on egts or ignition, I wish I could be of more help in that area. I know what you mean about not getting caught up in chasing power but I fitted that turbo and other parts to get to the power levels I want and won't be happy until I've got over the 450bhp I set out to achieve other wise all this will have been a waste of time and money! I will post al 3 graphs up later

I run Gems but use map, hence the Q.

PartyPete wrote:Toaster you may be right, But I'm going to fit a bigger cooler to be on the safe side, and Astra the gems is a very old ecu for group n rally's, the rule was it had to run maf to be able to compete,it has anti lag, I stupidly bought it in a rush. I will change it to a modern one in the future

Right then, here are all 3 graphs and the blurb I got when I picked up the car, I've highlited the relevant info.




What do you guys think then

I'm going to do a leak down test this weekend to rule that out?

Thought you said someone up your way mapped it yet says fusion on graphs

Yes it was mapped at a place local to me the last few times, but when it wouldn't make any more power he seemed reluctant to help and like he wasn't interested as well as some other things I wasn't happy about, so the last time it was mapped it was taken to fusion, this was over a year ago now.

And they got the same just over 400 ? What did they think it was then