High Flow Turbo

[3intheBack]

Pixel, all the advise of the last few posts is 'on the money' at this point in time. A GT30 on its own without the supporting 'fruit' on both sides of the turbo is overkill.

It's not that the GT30 was the wrong choice, it is a bit like buying a top of the line head unit for your stereo and plugging it straight into the factory speakers - it just aint gunna work like its supposed to.

Spend a couple of extra dollars on the exhaust (especially the front half) and then see how you feel...I reckon you'll be feeling a nice surge in your back at around 3000rpm.

P.S. Gap your plugs down to 0.7-0.8 while you're in there banging around.

Edited September 24, 2006 by 3intheBack

[pixel8r]

Pixel, all the advise of the last few posts is 'on the money' at this point in time. A GT30 on its own without the supporting 'fruit' on both sides of the turbo is overkill.

It's not that the GT30 was the wrong choice, it is a bit like buying a top of the line head unit for your stereo and plugging it straight into the factory speakers - it just aint gunna work like its supposed to.

Spend a couple of extra dollars on the exhaust (especially the front half) and then see how you feel...I reckon you'll be feeling a nice surge in your back at around 3000rpm.

P.S. Gap your plugs down to 0.7-0.8 while you're in there banging around.

Thanks heaps guys!!

This advice is really what I need right now. Its not that I dont enjoy driving my car (hell, its still a stagea!!) - but I went with the bigger turbo #1 because ATS recommended it (not for my setup but for long term better option) and #2 it gives the car so much more potential and value than simply putting back the piece that broke.

If I can pick up a cheap exhaust and cat I reckon that will improve things no end. What I'm getting now feels like sometimes its all free and the boost and revs build up fairly quick and the car feels very alive - yet other times it feels like the whole system is clogged up and i'm trying to stuff compressed air through a straw (literally i guess). I think this is all down to the exhaust.

I now have an apexi panel air filter (dry - not a major mod but got it for $50 bargain), and a manual boost controller so with this I now have no problems upgrading the exhaust. 3" all the way is what I really want to do, since my current setup is welded all the way so if I have to get it all done I might as well replace it all. Guess I can sell the stocker too

Tangles, thanks for the advice you've given. You're always giving me great ways to save money and still get the results I'm looking for - and thats fantastic. Sure it might be the cheap option but I figure its still going to be an upgrade and great value.

Just out of interest - does anyone know if my turbo would be the reason why my s2 only has 100awkw? Wondering if even though the boost guage shows 8psi pretty solid, if its actually flowing LESS air and therefore getting less from the engine...(too much backpressure so the turbo is working too hard to produce so little).

[AlexCim]

the gauge will never read more than the boost, this is because extra pressure isnt just going to come from no where?

why only 100kw?

dyno set up

conditions on the day unfavorable to turbo cars

wrong gear used on dyno

[pixel8r]

the gauge will never read more than the boost, this is because extra pressure isnt just going to come from no where?

why only 100kw?

dyno set up

conditions on the day unfavorable to turbo cars

wrong gear used on dyno

yeah but what I was thinking is that the guage is measuring air pressure isn't it? So if the turbo is struggling to push air through because of the amount of backpressure, I'm guessing the boost pressure is the same but actual airflow is less. Would this be correct? or is boost pressure an accurate measure of airflow regardless of any restrictions??

Other cars on the same dyno on same day were getting quite good figures (none of them AWD tho). Pretty sure they used 3rd gear.

Not too worried about the dyno readout. The car isn't a finished product yet anyway. If I'd done all my target mods and gotten a low figure then i'd be more concerned but at the moment its not an ideal setup so its hard to predict what the outcome should be.

[AlexCim]

airflow and boost dont have any direct correlation.

think of it this way, when you put your finger over the end of a hose it make it higher pressure, but the flow of the hose doesnt change does it?

[Silverback]

My Stagea really has been transformed with getting a new exhaust to free up the beast.

I went for the AM performance stainless Split Dump pipe, a full 3" Mild Steel Exhaust with bolt on flanges, a high flow cat which was recommended by the exhaust shop (its a good un') and two large bodied mufflers which actually have a straight pipe right through, but resonators to keep it quiet. I also opted for a twin pipe setup at the back to keep the right look with my body kit, and keep the stealth factor.

Its got a higher flow panel filter and stock ecu. The performance is much smoother through the rev range, particularly as it starts to get through the 3,500 - 6,000 rpm band. It just feels much less restricted. The torque increase in the mid range is noticable, and the fuel economy is much better. Smooth, hard acceleration is rewarded with crisper performance, and the RB25 just seems to love it.

I have had this setup on now for the last couple of months. It feels as if the ecu has remapped itself to take advantage of the new setup, as it has been consistently smoother since. Its just a much more rewarding car to drive.

I would totally encourage you to invest in a good, well designed exhaust and you wont regret it.

[pixel8r]

My Stagea really has been transformed with getting a new exhaust to free up the beast.

I went for the AM performance stainless Split Dump pipe, a full 3" Mild Steel Exhaust with bolt on flanges, a high flow cat which was recommended by the exhaust shop (its a good un') and two large bodied mufflers which actually have a straight pipe right through, but resonators to keep it quiet. I also opted for a twin pipe setup at the back to keep the right look with my body kit, and keep the stealth factor.

Its got a higher flow panel filter and stock ecu. The performance is much smoother through the rev range, particularly as it starts to get through the 3,500 - 6,000 rpm band. It just feels much less restricted. The torque increase in the mid range is noticable, and the fuel economy is much better. Smooth, hard acceleration is rewarded with crisper performance, and the RB25 just seems to love it.

I have had this setup on now for the last couple of months. It feels as if the ecu has remapped itself to take advantage of the new setup, as it has been consistently smoother since. Its just a much more rewarding car to drive.

I would totally encourage you to invest in a good, well designed exhaust and you wont regret it.

Thats a very nice and detailed description - I like it!

I'm now in the market for a good exhaust, and one question I have is about lag. Did the 3" exhaust INCREASE turbo lag? This is a problem I had when I put a 3" full SS exhaust on a s13 silvia (no other mods except high flow panel filter) - boost increased to 10.5psi and lag increased a little, although top end power was a lot better - 18kw better.

Is it worth the extra money for stainless? I guess another way to ask that question is - is there any benefit to stainless steel over mild steel other than it doesn't rust and lasts longer?

[Silverback]

Thats a very nice and detailed description - I like it!

I'm now in the market for a good exhaust, and one question I have is about lag. Did the 3" exhaust INCREASE turbo lag? This is a problem I had when I put a 3" full SS exhaust on a s13 silvia (no other mods except high flow panel filter) - boost increased to 10.5psi and lag increased a little, although top end power was a lot better - 18kw better.

Is it worth the extra money for stainless? I guess another way to ask that question is - is there any benefit to stainless steel over mild steel other than it doesn't rust and lasts longer?

Turbo lag has decreased. Its a bit more responsive in daily traffic e.g. taking off from the lights, squirts through traffic etc.

The Stainless Steel was a combination choice, i.e. I wanted the underbonnet to be clean looking, and stainless fits the bill, plus I got it for a reasonable price. The mild steel for the rest was recommended by the exhaust shop, basically it has a slightly different note, and it is cheaper. They painted the system a nice dark grey (heat treated, rustproof) and it looks nice.

The system was designed for my requirements (i.e. no increase in noise at cruising speeds, which is good for highway driving (90 - 120)), but its got a lovely note around 70-80k's which is great when cruising in traffic with the lock up clutch engaged in the auto.

[Tangles]

I have no lag....

I have read that the SITC can actually help decrease lag too when setup right, but Im unsure of this claim.

Sorry Pixl8r I havent got back to your PM, been tied up with my own personal issues I guess, apologies.

That x-force price you mentioned to me seems like a pretty good deal !

As far as a bellmouth dump goes, search Flynn Performance, you'll see 'em for $200, or chat to JustJap where I got mine from in stainless steel.

The hiflow panel air filter is a step in the right direction, your R34 standard SMIC will do the trick, so all youd really need is the exhaust for under $800 as discussed and *maybe* one day a 2ndhand safc to map it all nicely on the dyno. No reason why you wouldnt see 140-160awkw then. Hard to predict tho

Interesting to read Wolverine that the bellmouth was a better choice on your setup, nice !

[pixel8r]

I have no lag....

I have read that the SITC can actually help decrease lag too when setup right, but Im unsure of this claim.

Sorry Pixl8r I havent got back to your PM, been tied up with my own personal issues I guess, apologies.

That x-force price you mentioned to me seems like a pretty good deal !

As far as a bellmouth dump goes, search Flynn Performance, you'll see 'em for $200, or chat to JustJap where I got mine from in stainless steel.

The hiflow panel air filter is a step in the right direction, your R34 standard SMIC will do the trick, so all youd really need is the exhaust for under $800 as discussed and *maybe* one day a 2ndhand safc to map it all nicely on the dyno. No reason why you wouldnt see 140-160awkw then. Hard to predict tho

Interesting to read Wolverine that the bellmouth was a better choice on your setup, nice !

Cool.

Actually a few things have changed with our situation and it looks like we'll be spending a little more for a custom exhaust. Same place I got the exhaust for the silvia. Full Stainless 3" with high flow cat and magnaflow muffler (and centre muffler to reduce noise and drone). I've heard great reviews about AAA exhausts shop and was quite happy with the sound and performance of the exhaust in the silvia. With that car it made 18rwkw improvement over stock with no other mods and the sound was fairly quiet for a 3" and had a nice note. So they should be able to work some magic with the stagea too. Will cost a bit extra but the performance and sound of the exhaust is so critical that I thought I'd just take the plunge and get a full custom exhaust. I stand by the work of AAA exhausts and if you search in the SA section of the forum you'll find many others swear by them too.

So that will be going on soon. Hopefully fuel economy isn't upset too much (at the moment i'm off boost during city driving but if lag is decreased that may change - but other than that highway driving economy etc. should improve).

Will also be looking at a safc (2nd if possible - cant really go wrong) and that should complete my setup for now. Hoping for between 140-160awkw and will find out when the safc is tuned. Normally an exhaust should give around 20kw increase atw for imports but with the gt30 turbo i'm thinking this could really take off. Note that I also am getting a manual boost controller in the mail soon and that will allow me to fine tune things a bit for now. Will post the results when its done for those interested...

[66yostagea]

I have been reading "Gone With The Wind", aka SK DFA Thread.

On Feb 15,2005, Sk mentioned he got 134 4wkw At 10psi with an 11:1AFR.

He said thats pretty good for a stock S1 , a 30% improvemeht after spending $380.

That means a total stocker will only deliver 100 4wkw = or - a bit. True?

[pixel8r]

I have been reading "Gone With The Wind", aka SK DFA Thread.

On Feb 15,2005, Sk mentioned he got 134 4wkw At 10psi with an 11:1AFR.

He said thats pretty good for a stock S1 , a 30% improvemeht after spending $380.

That means a total stocker will only deliver 100 4wkw = or - a bit. True?

Thats what I figured was the standard stock power for a s1. Mine is S2 so *should* have around 120awkw or thereabouts but instead only has 100awkw. Definitely a RB25neo and definitely no performance mods other than the gt30. I think its just the gt30 turbo not able to work efficiently. Still sits at 8psi but I dont know if that has any relevance.

Anyhow it doesn't matter - the full 3" exhaust and manual boost controller goes on in 2 days so will look at how it goes then. Safc2 should follow soon after. Then the tune. Then I'm done.

The transformation should be niiiiiice.

[Silverback]

Cool.

Actually a few things have changed with our situation and it looks like we'll be spending a little more for a custom exhaust. Same place I got the exhaust for the silvia. Full Stainless 3" with high flow cat and magnaflow muffler (and centre muffler to reduce noise and drone). I've heard great reviews about AAA exhausts shop and was quite happy with the sound and performance of the exhaust in the silvia. With that car it made 18rwkw improvement over stock with no other mods and the sound was fairly quiet for a 3" and had a nice note. So they should be able to work some magic with the stagea too. Will cost a bit extra but the performance and sound of the exhaust is so critical that I thought I'd just take the plunge and get a full custom exhaust. I stand by the work of AAA exhausts and if you search in the SA section of the forum you'll find many others swear by them too.

So that will be going on soon. Hopefully fuel economy isn't upset too much (at the moment i'm off boost during city driving but if lag is decreased that may change - but other than that highway driving economy etc. should improve).

Will also be looking at a safc (2nd if possible - cant really go wrong) and that should complete my setup for now. Hoping for between 140-160awkw and will find out when the safc is tuned. Normally an exhaust should give around 20kw increase atw for imports but with the gt30 turbo i'm thinking this could really take off. Note that I also am getting a manual boost controller in the mail soon and that will allow me to fine tune things a bit for now. Will post the results when its done for those interested...

I would definately recommend making sure the front pipe (dump or split dump) is as wide at the top as possible. I have seen some models that basically only go to 3" after about 5cm from the turbo. Make sure it is a good one.

Looking forward to hearing whether your mods have a similar outcome to mine

[Tangles]

I have been reading "Gone With The Wind", aka SK DFA Thread.

On Feb 15,2005, Sk mentioned he got 134 4wkw At 10psi with an 11:1AFR.

He said thats pretty good for a stock S1 , a 30% improvemeht after spending $380.

That means a total stocker will only deliver 100 4wkw = or - a bit. True?

yah, spot on the money......

edit: my 1st tune towards end of 2005

Edited September 27, 2006 by Tangles

[pixel8r]

OK, time for the verdict...

Got the full 3" system installed today, all mandrel-bent (for what its worth) and I'm very impressed.

I'll admit it is quite droney around 2000rpm but either side of that it sounds great.

Sounds very tough too! Should reduce some of the 'volvo' comments

For those interested, boost did go from 8psi before the exhaust to 10psi after.

The low end response is GREAT. Still has a touch of lag but that has almost gone. What I mean is its not as brilliantly responsive as the stock turbo but once it STARTS to work it really starts to take off. Before it used to fall off boost abit when changing from 1st to 2nd but now it holds boost much better.

I think the top end now runs fairly rich as the power seems to fade when the revs get high.

I've got a SAFC2 on order (2nd hand) and when I receive that next week I'll be booking the car into boostworx asap to get it properly tuned. Should also have my boost controller by then so they'll be able to give me a really good compromise between boost and a safe tune (ie. AFR's).

Hoping for between 140-160awkw. 160 would be great, but if it falls a bit short I'm not going to be too unhappy.

The transformation is good. Noticeable less lag and greater response.