Educated Guess At The Final Tune Results

[Nismo 3.2ish]

Things don't seem to be necessarily optimal, but I'm not expecting to see miraculous improvements in power - perhaps some improvement in power delivery if it turns out the intake cam proves to be excessively retarded in practice.

I also do not expect any real over all power improvements. What I have is plenty.

What I would like to know is, if you have your intake side retarded by 3 or 4 degrees and you advance it 3 or 4 degrees , there is 6 or 8 degrees difference, what would this do for the low end power gain at lower rpms.

[XGTRX]

Never heard of an external wastegate opening due to exhaust pressure tbh, I'd consider it a design issue if it did - by function definition they are meant to block any flow until the reference pressures met targets - especially if it had both ports utilised.

If he is bleeding off a 12-14lb spring and has a higher than expected exhaust manifold pressure at wot due to a restrictive rear then the gate will crack open, no question. This always happens in this scenario, not the first time and it won't be the last.

With a larger higher flowing rear there will be a lot less manifold pressure at the same boost pressure, even running a 1.15 AR at 30psi I would expect to see less manifold pressure due to the lack of back pressure.

[Hadouken]

I think we should stop theorising and wait for when it goes onto another dyno. Then we know what is what

[AngryRB]

Just curious, if it was getting valve float in the top end, would you/could you tune around it by dropping the boost and retarding the cams?

The dyno curve looks like it gets a wiggle on a touch, maybe not significant?

[Piggaz]

Just curious, if it was getting valve float in the top end, would you/could you tune around it by dropping the boost and retarding the cams?

The dyno curve looks like it gets a wiggle on a touch, maybe not significant?

It won't be floating. I run the same cams, springs and retainers and have given my setup 30 psi.

Not sure how much more boost you want to pull out of it. It's dropping to 18 psi as is.

[XGTRX]

I think we should stop theorising and wait for when it goes onto another dyno. Then we know what is what

Why? Just discussing what lith brought up. That's all. Edited July 6, 2015 by XGTRX

[XGTRX]

I also do not expect any real over all power improvements. What I have is plenty.

What I would like to know is, if you have your intake side retarded by 3 or 4 degrees and you advance it 3 or 4 degrees , there is 6 or 8 degrees difference, what would this do for the low end power gain at lower rpms.

Theoretically yes but really this is usually the last thing you do after the rest of the set up is A OK.

[jangles]

It won't be floating. I run the same cams, springs and retainers and have given my setup 30 psi.

Not sure how much more boost you want to pull out of it. It's dropping to 18 psi as is.

I think he was more leading towards that being a possible reason its like it is.

[Nismo 3.2ish]

Theoretically yes but really this is usually the last thing you do after the rest of the set up is A OK.

Don't you think I am at the last thing already , lol ??

[Scooby]

How's the water Pete?

When is it booked in for the next tune?

[XGTRX]

Don't you think I am at the last thing already , lol ??

JEM will tell you soon enough Edited July 6, 2015 by XGTRX

[Nismo 3.2ish]

How's the water Pete?

When is it booked in for the next tune?

Hi Mark, waters all good

Just waiting for some other work to be finished in the shop, not much use leaving it there until he can work on it , maybe another week or 2. Not just the tune to do and I can still use the car while I am waiting

[Mick_o]

JEZ will tell you soon enough

FYP

[Nismo 3.2ish]

FYP

I wondered who that was

Thought it was Just Engine Management ???

Edited July 6, 2015 by Nismo 3.2ish

[DJBarnstar]

I've got to say I would be pretty unhappy with that boost drop.

Kind of like getting married to a hot Virgin, and then being told you have to use a condom for the rest of your life......

[Nismo 3.2ish]

I've got to say I would be pretty unhappy with that boost drop.

Kind of like getting married to a hot Virgin, and then being told you have to use a condom for the rest of your life......

Yeah a bit of bummer

I will still take the Virgin , condom and all

[XGTRX]

JEM will tell you soon enough

Woops sorry. You know who I mean.

[sky30]

If it's the turbo selection that is causing these issues.... Everything else is irrelevant. See what the new tuner says.

Fairly narrow minded, all you can say is its the turbo. Its rated for over 700hp ffs, if there are no other restirictions it should acheive close to that.

Can u tell me why my engine with a .82 rear housing does not have this issue?

[Lithium]

I am starting to agree with the plausibility of his theory - I wouldn't go so far as to say that's the issue, but.

You have a .82 open housing, a .84 open housing is a different beast and in most cases I would expect it to be more comparable in to a .6x open housing which would make people shit themselves if it was said that someone was going to put on a 3.2 litre aiming for 400kw+ on petrol.

When I first heard about this I thought the hotside was going to be too small and that was before I learnt it was a small divided hotside on it, I've never thought about or had to deal with a bad turbo match like this causing excess back pressure - I like to think all the things I have been involved with have quite well matched turbos and as such exhaust manifold pressure has tended to be sane and never thought about the effect on the waste gate but the more I think about it the more it makes sense. Always nice to learn something

[Nismo 3.2ish]

Fairly narrow minded, all you can say is its the turbo. Its rated for over 700hp ffs, if there are no other restirictions it should acheive close to that.

Can u tell me why my engine with a .82 rear housing does not have this issue?

Hope your right

I spoke to the bloke at Precision Turbo and he said it "should" not loose more than 50HP with the 3.2 . With some blokes taking these turbos up to 740HP with varied sized motors ? ?