High Flow Turbo

[pixel8r]

i might need to get my turbo hi-flowed sometime soon coz right now i need to floor the pedal to get any real response from the turbo...under normal acceleration the turbo kinda feels really lagging ...but on 2nd thoughts that might have something to do with AFR's ...maybe if i lean it out just a bit on the low end then the engine should feel more responsive...any thoughts?

Hmmm this sounds like there's a problem somewhere. A highflow turbo really wouldn't be a good idea unless you have a problem with your current turbo (my situation), or you have the supporting mods to make it safe and worthwhile (my guess is fmic, boost controller, safc or equivalent, and exhaust).

The stock turbo is not what I'd call lagging or lacking response. Its actually very responsive but cannot handle a lot of boost (ceramic wheel). So I'd want to be sure there are no issues with your current setup before looking at a highflow option.

[AlexCim]

with a full exhaust, gcg and 13psi, my S1 made 160awkw

i wont be slapping it back on the dyno, but dont worry, i wont have forgotten what boosting feels like

[pixel8r]

with a full exhaust, gcg and 13psi, my S1 made 160awkw

i wont be slapping it back on the dyno, but dont worry, i wont have forgotten what boosting feels like

Obviously they weren't the only mods (boost controller, fuel or afm-related piggybacks, bigger cooler?)

Thats roughly the sort of power figure I want to end up with. Not planning on running huge boost, probably around 12-13psi would be nice. Just a matter of getting the supporting mods to run that kind of boost. I think at 8psi (gt30 - i think that means more air than stock at same psi?) I'm running into cooling problems but not sure. Its s2 so its got the r34 gtt cooler.

I'm thinking fmic, exhaust (not sure if I need full 3" or just catback? anything that will reduce lag would be great), and safc.

Already have boost controller (not installed yet).

[fcruz3r]

well i have the s1. current mod on it is just a 3 inch exhaust turbo back. currently in hand

1. apexi safc (3 units actually - looking to sell off 2 ..interested? ..look in the for sale forums..lol <<free advertising)

2. blitz twin solenoid boost controller & greddy profec b <<can't decide on which one to use and which one to sell off. ...prolly go with the profec b

Dont have the $$$ for an FMIC at the moment...so with just the boost controller, afc and exhaust mod...what do you reckon is a reasonable ask in terms of rwkw?....im hoping 130@12psi (would this be too much for the stock cooler?)

[Tangles]

Id suggest youd pull 130 easy up to 140 awkw at 12psi with that little list.

nothing wrong with 140awkw, enjoyed that setup for a while (with a R34 SMIC)

I admittedly enjoy the 160awkw at 12psi a lot more tho

.............. and I suspect I'll be a fan of 190-210awkw at 1bar too

with the 'cooler, just buy a cheap core and a pipe kit (ebay, lol) and mock up a return feed pipe setup. not expensive at all.

[AlexCim]

Obviously they weren't the only mods (boost controller, fuel or afm-related piggybacks, bigger cooler?)

Thats roughly the sort of power figure I want to end up with. Not planning on running huge boost, probably around 12-13psi would be nice. Just a matter of getting the supporting mods to run that kind of boost. I think at 8psi (gt30 - i think that means more air than stock at same psi?) I'm running into cooling problems but not sure. Its s2 so its got the r34 gtt cooler.

I'm thinking fmic, exhaust (not sure if I need full 3" or just catback? anything that will reduce lag would be great), and safc.

Already have boost controller (not installed yet).

Yes, actually they were the only "power" mods. Complete stock untouched ECU. Just boost upped.

Had a GTR FMIC too, but that isnt making power on its own, only improves the flow. For example, i'd have made the same power with a stock SMIC but it just wouldnt have been as early/smooth. Plus, I dont really think a fan blowing on a cooler on the dyno can help THAT much.

Im expecting around 140awkw with the high flow and stocko rest. Might see how far I can push the boost until I hit R&R

[66yostagea]

well i have the s1. current mod on it is just a 3 inch exhaust turbo back. currently in hand

1. apexi safc (3 units actually - looking to sell off 2 ..interested? ..look in the for sale forums..lol <<free advertising)

2. blitz twin solenoid boost controller & greddy profec b <<can't decide on which one to use and which one to sell off. ...prolly go with the profec b

Dont have the $$$ for an FMIC at the moment...so with just the boost controller, afc and exhaust mod...what do you reckon is a reasonable ask in terms of rwkw?....im hoping 130@12psi (would this be too much for the stock cooler?)

SK reckons a stock R34 sidemount willdo 200kw. There is a thread in the DIY section onan R34 conversion

[fcruz3r]

SK reckons a stock R34 sidemount willdo 200kw. There is a thread in the DIY section onan R34 conversion

is the stock turbo capable of 200kw? If so..what kinda boost pressure we talking about?

[pixel8r]

SK reckons a stock R34 sidemount willdo 200kw. There is a thread in the DIY section onan R34 conversion

It may be able to cope with it but how well?

Cooler air is always better so a better cooler will still improve things over the stock cooler.

Would be interesting to actually see the difference.

[pixel8r]

Yes, actually they were the only "power" mods. Complete stock untouched ECU. Just boost upped.

Had a GTR FMIC too, but that isnt making power on its own, only improves the flow. For example, i'd have made the same power with a stock SMIC but it just wouldnt have been as early/smooth. Plus, I dont really think a fan blowing on a cooler on the dyno can help THAT much.

Im expecting around 140awkw with the high flow and stocko rest. Might see how far I can push the boost until I hit R&R

Sounds good.

So that makes me wonder. If I can get away without touching anything on the fuel side (injectors/fuel pump etc) I'd be very happy.

I'm still well away from R&R (AFR=11 at the top end so a bit of room to move) and my fuel economy is better than before so a bit more richness isn't going to bother me.

Still puzzled as to why I have only 100awkw with a s2 and gt30 turbo running 8psi. Maybe I have some other problem somewhere.

The main 2 things I want is bigger exhaust and bigger cooler (if i need it) so if I can get by with just an exhaust for a while that'd be great. Getting manual boost controller soon so that will be good for later on. Should be able to bump it up to 10psi for now tho - nice round number.

[66yostagea]

It may be able to cope with it but how well?

Cooler air is always better so a better cooler will still improve things over the stock cooler.

Would be interesting to actually see the difference.

SK also did an evaluation on the air deflector. I've got one on order

The colder the air the denser it is. Denser air has more Oxygen = more power.

[3intheBack]

I dont see how a small intercooler would make a lot of difference on a short dyno run unless it is acting as an airflow restrictor - ie a boost pressure drop across the core - which can happen if you are running a large turbo. I believe this is what SK is referring to when he says a stock R34 IC is good for 200 kw (in terms of flow).

The size of the IC only becomes an issue when it is unable to dissipate the heat being generated by the turbo. Which is only going to be problem on the road on hot days or after a number of dyno runs close together.

I definitely think the most critical part of the exhaust is the front dump pipe upto and including the cat. The standard stagea dump pipe has a small cat, barely 2.5 inches in diameter only 12 inches from the turbo before the exhaust moves down the pipe 3 feet to the next cat. This kind of back pressure will stop your turbo spooling up freely. That is why everybody raves about the new found mid range torque they have with a decent front/dump pipe setup into a 3.5 inch cat.

Edited September 21, 2006 by 3intheBack

[66yostagea]

Nice one Wazza. That is all going into my letter to Santa this year. :nuke :

[pixel8r]

I dont see how a small intercooler would make a lot of difference on a short dyno run unless it is acting as an airflow restrictor - ie a boost pressure drop across the core - which can happen if you are running a large turbo. I believe this is what SK is referring to when he says a stock R34 IC is good for 200 kw (in terms of flow).

The size of the IC only becomes an issue when it is unable to dissipate the heat being generated by the turbo. Which is only going to be problem on the road on hot days or after a number of dyno runs close together.

I definitely think the most critical part of the exhaust is the front dump pipe upto and including the cat. The standard stagea dump pipe has a small cat, barely 2.5 inches in diameter only 12 inches from the turbo before the exhaust moves down the pipe 3 feet to the next cat. This kind of back pressure will stop your turbo spooling up freely. That is why everybody raves about the new found mid range torque they have with a decent front/dump pipe setup into a 3.5 inch cat.

I didn't have any boost pressure drop on the dyno (if thats what you mean) - it held 8psi very constant, only dropping slightly at the very top end (say down to 7.5psi?). I'd probably look at replacing the entire exhaust if I was going to do that. As a minimum I'd go for dump/front pipe + cat and make sure the catback section is bolted on to make it easier to change later on. But for the remaining cost of the catback section its probably worth doing the entire exhaust at once.

[AlexCim]

pressure drop across a core is when you measure the difference between the boost on one side of the core to the other.

your car would have held 8psi constantly yes, but what if there was a 10psi drop so your turbo was actually blowing 18psi. See the lack of efficiency.

[66yostagea]

pressure drop across a core is when you measure the difference between the boost on one side of the core to the other.

your car would have held 8psi constantly yes, but what if there was a 10psi drop so your turbo was actually blowing 18psi. See the lack of efficiency.

Alex, wouldyou put in two boost gauges? Then you could see if there was any differential between tourb boost and what was actually getting to the inlet manifold . Or would that be a waste of time effort and money?

[wolverine]

66yostagea check your pm's

measuring pressure drop is as you have described. race teams will check pre-IC, post IC and exhaust manifold pressure.

[pixel8r]

pressure drop across a core is when you measure the difference between the boost on one side of the core to the other.

your car would have held 8psi constantly yes, but what if there was a 10psi drop so your turbo was actually blowing 18psi. See the lack of efficiency.

ok. still not very clear to me how it all works. All I can think of is that because my exhaust is so restrictive (stock exhaust) the backpressure will build up boost pressure quicker so it will still read 8psi but the airflow is less since the turbo is having to struggle against backpressure to actually put air through...does this make sense? am I way off track here?

Am really hoping a 3" exhaust will fix the lag and low kw issues. The gt30 turbo is a big jump from stock and I went on the recommendation of the guy that works with turbos all day that installed mine. But it seems it never really reaches its optimal efficiency until about 4000rpm. If an exhaust or any other mod is not likely to fix this, then I have to say the gt30 will be coming off again and a unit more similar to stock going back on. All along I've been thinking its just because of the exhaust - but I dont want to spend $1k on an exhaust only to find its still very laggy.

[Tangles]

search R33 exhaust on ebay; you'll come up with a 3inch bellmouth dump pipe from turbo to cat, and a 3inch highflow skyline catconverter. $400 delivered for the 2. Unleash the beast thats in your turb setup mate !

Did ppl know that a R33 skyline exhaust system WILL fit?, so buy a used catback system. It'll be 20cm too short, so cut it and weld on a 3inch piece. This is whats on my car, cheap but it does the job. 160awkw on the standard turbo is testiment to the efficiency.

Mate, you'll lose shiteloads if you go to sell the GT30 highflow now. Look around and you'll be able to knock up a full 3inch system for $800. Then you'll be impressed with the setup youve got, no doubt.

edit: modifying is never cheap tho, lol as we all know..... maybe look for a used safc too?

Edited September 24, 2006 by Tangles

[wolverine]

pixel at the very least bolt on any 3" exhaust system. once you have done this you can reassess the GT30. like most others here i think it is a touch too large but (like tangles says) until you uncork the restriction on the exhaust side, the turbine will struggle to turn the compressor efficiently. the response should improve dramatically once you do this.

we tried both split and bellmouth dumps on my stagea and the bellmouth made more power with less exhaust side restriction. i can't vouch for this being consistent as the common wisdom is to go the split dump due lower turbulence when the wastegate cracks open, nevertheless we chose what worked best in our case.