Educated Guess At The Final Tune Results

[Nismo 3.2ish]

What was your original power goal with this build?

I had no real power goal Daz and went the other way, I tried for throttle response and still trying , LOL ( I bought the wrong car, did not do my homework) it was a spur of the moment buy and I was feed a lot of bullshit from the sales bloke, said, after I run it in, it would tune up at 800HP, I thought, 800HP, FFark!.

Since I have been on SAU it has made me feel pretty stupid believing him and not understanding how a 800HP with a big single would have driven on the street , absolute DH and have had that said to me, many times

But from what I could work out using the mods I had, I thought it would Dyno at around 420KW on 98 pump. Tuner mentioned that my exhaust was holding the tune back. I think from what a few blokes have said , there is more to get from the tune, as it is ?

The build is pretty strong and can handle whatever is needed, $s. Later I will upgrade the fuel line and get a flex tune and would think on E85 it will Dyno @ approx 450KW

[Hadouken]

400kw will be plenty for you. We can all have peak power but it's the area under the curve. And I think yours will be fine now with exhaust being updaed

[Nismo 3.2ish]

400kw will be plenty for you. We can all have peak power but it's the area under the curve. And I think yours will be fine now with exhaust being updaed

Yeah mate. 400 is more than plenty as a DD. Just trying to get it as early as I can with what mods I have got on the car.

A few blokes I email with on SAU think there is more of what I want left in the tune and think those cams can be tweaked a bit more to help, hopefully I will get something from the tuner today, well

I guess if I am not happy at the end of all of this a new turbo will get me there, haha

I have a lot of left over parts that I can sell to make the changes I want, so I can afford it

The only parts I have taken off this car that I have put on are the Poncams B , all the rest were from the build before I bought it

[XGTRX]

Fired off a few emails asking when the tune will be finished and since everything else has been fixed, it is only the FINAL TUNE to be done, should be interesting to see if the 3.5" Dump & Cat can pick up 14KWs to nudge it over 400KW, BUT more importantly, if it feels any different to drive

It will be a totally different car. The previous exhaust setup was a nugget. Just be careful until you get used to the newfound midrange torque explosion.

[Stixbnr32]

Yeah some people do not really understand what happens when you chuck the biggest turbo(s) on to get that dyno queen number.

[Nismo 3.2ish]

It will be a totally different car. The previous exhaust setup was a nugget. Just be careful until you get used to the newfound midrange torque explosion.

Do you really think it will make that much difference, I would rather it to be going hard at 3000rpm ish and do not care if it does not want to go over 70000rpm. So I will wait until I finalize everything and make a decision depending how it goes. It is not far off what I want now

[Nismo 3.2ish]

Yeah some people do not really understand what happens when you chuck the biggest turbo(s) on to get that dyno queen number.

I had not idea how any of it worked, I was easy meat for the salesman, I had a TT300ZX and put a TT on a 350GT and they were pretty good, so a turbo was a Turbo, what a wanker, LOL

But I have to say, I am enjoying the experience, well except dealing with Mod shops, that can be VERY frustrating

[luke gtr]

Do you really think it will make that much difference, I would rather it to be going hard at 3000rpm ish and do not care if it does not want to go over 70000rpm. So I will wait until I finalize everything and make a decision depending how it goes. It is not far off what I want now

it will make a huge difference.

I went from twin 2 to 3, up to ten 3 to 4 with my old twin set up.

Had the boost t set to 18psi.

With just r he exhaust sway, boost went straight to 30psi.

No other changes.

I'm sure you'll enjoy it.

Should sound a little better too.

[XGTRX]

it will make a huge difference.

I went from twin 2 to 3, up to ten 3 to 4 with my old twin set up.

Had the boost t set to 18psi.

With just r he exhaust sway, boost went straight to 30psi.

No other changes.

I'm sure you'll enjoy it.

Should sound a little better too.

Same, picked up so much midrange doing the same thing. Chalk and cheese really

[Nismo 3.2ish]

sounds great, most of my expectations have not been meet so far, close, so hoping for better result this time or next time

[Nismo 3.2ish]

it will make a huge difference.

I went from twin 2 to 3, up to ten 3 to 4 with my old twin set up.

Had the boost t set to 18psi.

With just r he exhaust sway, boost went straight to 30psi.

No other changes.

I'm sure you'll enjoy it.

Should sound a little better too.

Hi Luke, not sure if I can explain myself but ?

You were going up 1" at a time, what's that, about + 72% Volume, I am just going 1/2", 36% but only from the Dump and Cat and then using the existing Custom 3 1/2" Exhaust.

Is the 3" dump and cat to the exhaust enough to restrict the flow to the tip buy the full 36% or partially ?

[XGTRX]

That doesnt tell the full story though. There was a good article on autospeed i read ages ago. I will try to find it for you.

[XGTRX]

found it

http://www.autospeed.com/cms/article.html?&title=Pure-Pipe-Perfection-Part-1&A=0877

important sections of the article:

Going from 2 1/4 to 3 inch.

Hungry for an Improvement?

Before running out and whacking a new system onto my Commodore VL turbo (which is already equipped with a high-flow air intake), I first wanted to see how badly the car needed a big exhaust. Was investing a large bundle of cash in a new system gonna be beneficial, or was I just squirting it up against a wall?

The only way to tell is by measuring the engine's displeasure, in the form of exhaust back-pressure. Back-pressure can be measured with any accurate boost pressure gauge connected through the wall of your exhaust pipe. Under high engine load, pressure builds in the exhaust and you'll soon see how choked up the engine gets. In my VL turbo's case, I decided to take measurements at two different points in the factory system - one at the first bend in the exhaust pipe, and another right up behind the turbocharger (in the cast elbow). My aim here was to identify how bad the factory dump pipe/elbow was. The pressure fitting in the exhaust pipe was easy to tap (I had a short length of metal brake line welded flush into the side of the pipe), but the one behind the turbo needed a little more ingenuity. I opted to make up a fitting to screw into the location of the factory EGO sensor. This was constructed from a threaded bolt with a hole drilled through the middle and a short length of pipe welded onto the end. Rubber hose was used to connect each fitting to the in-cabin pressure gauge.

Now, I had already suspected that the standard (2½ inch) Holden AC cat converter was collapsing - and this was confirmed when I saw how far the needle on the pressure gauge swung around. On the road - at full power - there was an 80 kPa (11.6 psi) build-up in the exhaust bend and a full 90 kPa (13.2 psi) at the back of the turbo. Ouch - that's a helluva lot! Note that the closer to the engine you take your measurement, the higher the cumulative back-pressure reading will be. Naturally.

Curious to see how much of that monumental amount of back-pressure was caused by the obviously clogged cat, I dropped the sucker from the car and took to its inners with nothing less subtle than a crow bar. After a couple of minutes of battering, the entire inside of the cat converter was removed and its hollow shell then re-fitted to the car. Back on the road (with the boost pressure gauge fitted to the first exhaust bend) the exhaust back-pressure was still through the roof. Try 70 kpa (10.3 psi) at full noise... Indeed, a noticeable improvement in response and torque was felt with the collapsed cat guts removed - but, regardless, this level of back-pressure was still way too high for any high performance application.

AND AFTER THE EXHAUST INSTALL

After choosing the right vital indigents, the VL's new exhaust has made it a different car - and for a grand total of only $630 (including the $220 cat). Throttle response is vastly improved, boost builds much quicker and top-end urge is markedly up. (accidental wheel spin off the line is now very common!) And peak exhaust back-pressure? Well, our initial reading at the front of the system (just behind the turbo) has fallen from a huge 90 kPa to a mere 20 kPa - a stonking 82% reduction in back-pressure! And restriction across the factory cast dump pipe was not even measurable! Of course, this reduction in back-pressure has also yielded a significant increase in 0-100 km/h performance, with times falling from 7.6 to 7.1 seconds (measured during 30-odd degree C ambient temperatures).

[Daz]

I had no real power goal Daz and went the other way, I tried for throttle response and still trying , LOL ( I bought the wrong car, did not do my homework) it was a spur of the moment buy and I was feed a lot of bullshit from the sales bloke, said, after I run it in, it would tune up at 800HP, I thought, 800HP, FFark!.

Since I have been on SAU it has made me feel pretty stupid believing him and not understanding how a 800HP with a big single would have driven on the street , absolute DH and have had that said to me, many times

But from what I could work out using the mods I had, I thought it would Dyno at around 420KW on 98 pump. Tuner mentioned that my exhaust was holding the tune back. I think from what a few blokes have said , there is more to get from the tune, as it is ?

The build is pretty strong and can handle whatever is needed, $s. Later I will upgrade the fuel line and get a flex tune and would think on E85 it will Dyno @ approx 450KW

Yes agreed. Although I would like 450kws Id happily sacrifice a little from the top end for more midrange. I've tried a few different low mount turbo set ups, hopefully I've got it right this time also a good tuner is critical

[Nismo 3.2ish]

Yes agreed. Although I would like 450kws Id happily sacrifice a little from the top end for more midrange. I've tried a few different low mount turbo set ups, hopefully I've got it right this time also a good tuner is critical

No crap, I would be happy with any gains from idle and the dyno numbers would mean shit all to me, well except when piss talking, but I could make that up as needed

What Turbo/s do you have now ?

I would love a tuner with some communication skills

Edited June 16, 2015 by Nismo 3.2ish

[luke gtr]

Hi Luke, not sure if I can explain myself but ?

You were going up 1" at a time, what's that, about + 72% Volume, I am just going 1/2", 36% but only from the Dump and Cat and then using the existing Custom 3 1/2" Exhaust.

Is the 3" dump and cat to the exhaust enough to restrict the flow to the tip buy the full 36% or partially ?

sorry, yes one inch, but I was describing the merge collector.

So, twin 2"into a 3" exhaust.

Replaced with twin 3" into a 4" exhaust.

Going off circle area volumes, the main exhaust doubled in size.

Makes a gigantic difference.

And exhausts restrict at the smallest point.

So, the flow would be affected .

I believe you'll definitely feel and hear a difference.

[luke gtr]

I would love a tuner with some communication skills

quoted for truth.

[Daz]

My new tuner is farkin pricey but hopefully its a case of you pay for what you get

[Nismo 3.2ish]

sorry, yes one inch, but I was describing the merge collector.

So, twin 2"into a 3" exhaust.

Replaced with twin 3" into a 4" exhaust.

Going off circle area volumes, the main exhaust doubled in size.

Makes a gigantic difference.

And exhausts restrict at the smallest point.

So, the flow would be affected .

I believe you'll definitely feel and hear a difference.

Thanks for the info, so I should get a fair bit of the 36% volume from the extra 1/2" dump and cat , all good

Not looking forward to any more DBs on the exhaust, I want it as quiet as I can get it.

[Nismo 3.2ish]

My new tuner is farkin pricey but hopefully its a case of you pay for what you get

What did your tune cost ?

My last 98 pump tune cost $1600, I call that farkin pricey

I thought it must have been for a flex tune