Restriction In The Exhaust

[XKLABA]

This thing was making better power before the ECU changed and everything else is the same except now the exhaust is better so clearly the issue is in the ECU where it be the settings or simple the tune

Clear some space in your inbox, I too tried sending you a PM

[hy_rpm]

You can't compare dynos they don't all read exactly the same and it's was retuned after the exhaust

[rondofj]

Yeh it was making better power at lower boost too (286rwkw @18-16psi) but it does drive much smoother now esp in low rpms before boost and noticeably more power/torque in low rpms too. Now 280rwkw @22-18psi it makes less power with a better exhaust and supposedly better ecu; so it can only be one thing wrong with the system, (not the ecu) need I say it, and yes dynos do read different too.

I will re visit them to get the power loss at downshifts sorted, have cleared my inbox, please try sending pm now, cheers

[Badgaz]

16kw difference? lets say 5kw could be any of the common variables that affect power on any given day..you're looking at a 11kw difference, this could be the difference in 1 or 2 degrees timing at wide open throttle.

the default Powerfc accelerate injector settings can richen up mixtures alot when you press the go pedal, they may have only been tuning wide open throttle? IMO full range torque is better than top end power any day of the week...especially on the street.

[scotty nm35]

so it can only be one thing wrong with the system,

I assume you have tried a new CAS by now, after my suggestion of it on the first page?

[blah_blah]

Ah this reading this thread is like De ja vu of the issues I had

Not saying its the exact same issues i had though...

[Ben C34]

Ah this reading this thread is like De ja vu of the issues I had

Not saying its the exact same issues i had though...

Have you thought about me while buying lube and condoms lately?

[blah_blah]

Have you thought about me while buying lube and condoms lately?

Yes, I bought the strawberry/banana flavored ones since your just so juicy. nohomo.

Anyways back on topic

My issue was the CAS, but only because the engine got so hot to the point the block warped and the plastics around it melted. Otherwise not sure if its a usual wear and tear item

[rondofj]

have read a few good things about this ebc:

http://www.ebay.com.au/itm/Genuine-GIZZMO-3-5Bar-IBCR-RPM-Electronic-Boost-Controller-R32-R33-R34-Skyline-/171197109666?pt=AU_Car_Parts_Accessories&hash=item27dc2495a2

http://www.ebay.com.au/itm/All-New-GIZZMO-3-65Bar-53PSI-MS-IBC-MSIBC-v3-Electronic-Boost-Controller-/171236535378?pt=AU_Car_Parts_Accessories&hash=item27de7e2c52

Out of those two, which one is closer to the old proven Gizzmo IBCR?

Yay or nay?? And Scotty, no I haven't tried a different CAS, cant find one lol..

[hy_rpm]

You can't 100% trust a dyno number

It's how it drives and the speed it pulls at the quarter mile is accurate

I went to latest rigoli dyno day and made 260kw was tune the week before at Unigroup 266kw

Seen a turbo civic the had a dyno sheet on the window tune by Jem and made 280 odd kw on rigolis dyno only made 224kw go figure

[hypergear]

By the looks of it, Its just bolted onto stock exhaust manifold and externally gated off rear housing. So the question is how much factory exhaust manifold can flow, and my evaluation result says 280rwkws on P98 unless excessive amount of boost.

The compressor design with huge impeller radius and plus antisurge housing makes it very un-efficient unless huge amount of boost given. In which you can not run those boost levels with a 65mm / 56mm turbine in a .63 rear.

My advise is get a proper exhaust manifold, a .82 turbine housing, a 50mm external gate. Then run heaps of boost.

[rondofj]

My car made 280rwkw at 18psi, not 22psi, by the time it made the power after 7k rpms thats how much the boost had dropped. Will an ebc hold consistent 22psi till 7k rpms? Power might go up then but by how much is anybodys guess.

[rondofj]

Stao, Im already running heaps of boost on 98 @22psi, so thats outa question, manifold n bigger gate imho is a waste, 0.82 rear could give gains though

[rondofj]

[hy_rpm]

Ebc will only help to extent but if there's is too much backpressure blowing the gate open at high rpm

It's going to drop boost no matter also when the turbos out of flow it will drop but I doubt the turbos maxxed as my mate made 360kw with a 5558 on e85 sr20

A smaller wastegate may also help as there won't be as much pressure blowing on it as it's physically smaller

But those are only bandaid fixes which might only help slighty

But a larger rear housing and proper manifold is a proper fix if you want 300kw plus

[hypergear]

I can see boost started to tapper as soon as peek was reached.

This can happen because the compressor is inefficient to feed the engine with that much of Air at given RPMs.

Or the exhaust manifold pressure is too high that blows the gate open. And when it has an external gate it means the EMP is very high.

Taken example given by Hy_RPM then it will be more likely that the turbine end is maxed.

There isn't a real lot of point of trying to hold the gate shut in this situations as it will makes the engine wants to pin. So you end up running higher boost on less timing and not alot of gain. Of course you can cure it with E85 or Q16 that marks your Ign timing closer to its peek torque output. Run a smaller gate will only increase EGT, in situations like this is very wrong.

Some thing like this is a perfectly balanced setup between induction and discharge. It is running an 38mm internal gate also:

SR is 4cyc engine with 8.5 compression. So it won't be copping with back pressure issues as what RB engines gets, generally makes a lot more power in a smaller turbine housing. So a .82 turbine will definitely make some changes to boost curve, and lot more power.

[rondofj]

A guy with PT5558 on R34 neo made 372rwkw @26psi, the only difference- he had e85, top mount ex manifold and ffp. Mick O made 335kw on stock manifold btw...

[rondofj]

That 5558 was also 0.63a/r btw

[hy_rpm]

Yeah but your comparing yours to different setups

The other guy made the extra power from e85 and more boost and he has a more free flowing manifold and inlet plenum so can make use of the extra boost aswell

Your will be restricted by boost now as your on 98 so more boost will just ping

But waste your money elsewhere up to you

Tuner has already guided you in the right direction

There's a restriction somewhere but the cat and exhaust wasn't it as it didn't gain much once you changed them

[hy_rpm]

Also mick o was on e85 wasn't he so would of just masked abit of the pinging and allowed abit more leeway before pinging