Jump to content
SAU Community

Recommended Posts

Hey i recently had a GT35/40 turbo on my rb25 but it had a .63 ex housing when i bought it, well that was abit responsive and not ideal for the power range im after, so it is now sold.......... my issue now is im not sure whether to buy another GT35/40 turbo with a larger ex housing OR use a T04Z with similar size ex housings.....anyone no which would be a better choice???? Power output im chasing is 450hp at wheels, lag could be an issue, so thats why im asking for any opinnions.... cheers guys.. 35/40 or T04Z????? oh n i forgot to mention, its a t3 flange at the moment but am changing that to t4 at present so both turbo choices will be used in conjunction with a T4 flange

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/
Share on other sites

I'll help you see the silly.

T04z - upto 450rwkw.

So if you only want 330rwkw, then its not smart to go a big huffer like the t04z.

The GT35 is far better suited to that range and will be more responsive and feel a truck load better for only 330rwkw.

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3220471
Share on other sites

gt3540 82 rear on a top mount manifold well designed ie: 6boost, external gate, and 19psi roughly? :dry: As sugested much much better than the T04z.

1+ the T04Z prefers 24psi and upwards of boost where as the 3540 will spool earlier and less boost to make better power? as far as i can gather

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3220596
Share on other sites

What he forgot to mention is the engine is about 2.7L... If that changes which turbo to go for or not I dont know. But its handy to have some specs on the engine.

how does rb26 crank and rods = 2.7L?!?

i would definately go the gt3540r, supports your aimed power output with better response and also suits your engine build better, t04z is too big and i would imagine you would start breaking internals :rolleyes:

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3221383
Share on other sites

na its 2.6 not 2.7...cheers nismoid, your a legend.. the .63 ex housing on my previous 35/40 would start to make boost at 2800rpm, im looking for one that comes on song about 4000rpm.. give or take. but ideally if the target hp (450hp) is reached then i'm happy either way... next is the fact the manifold has a t3 flange, with previous turbo (.63 ex housing) the housing and manifold and top of dump pipe would glow red at cruise on dyno, not even giving it a power run, was thinking maybe the t3 flange is abit restrictive so enlarging to t4 flange might have to be the go this time round also.????????????

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3221976
Share on other sites

um not on cruise they dont, when i told the tuner he stopped n let car idle till things stopped glowing, wasn't even boosting it, my mates hi mount turbo sr20 that was there with me only glowed once they did some full power runs

Yes they do champ. At cruise the AFR's are considerably leaner and as such, make for much hotter exhaust gasses. Your manifold is more likely to glow like that at part throttle and cruising than under medium to full load.

Fact.

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3222304
Share on other sites

ok, my bad, its just that i thought of it this way........ with power comes heat, for example lets say we have a car that makes 400hp flat out, and to keep it simple maths we'll say it uses 100hp at cruise which is only a 1/4 of its potential hence internal combustion temps not being that hot so i didnt think the manifold would glow however at full noise your using 400hp its now making 4 times the power and your internal combustion temps have gone through the roof hence exhaust metals changing colour. this is the way i thought it was, regardless of mixtures being lean or rich, at the end of the day if your cruising you wouldnt think the internal temps would get hi enough to glow manifold unless there was a build up of....back pressure due to t3 flange or .63 ex housing?? now i may be wrong but i dont remember seeing cars exhaust glowing on cruise unless there was a restriction....???????? make any sense?

Link to comment
https://www.sau.com.au/forums/topic/175853-turbo-choice/#findComment-3225754
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yep, so far most have said that it looks like corrosion on the wall from piston not moving. Which then has probably damaged the oil rings and caused those vertical marks. The longest the engine was still after the rebuild, was the winter of 2018 - 2019, plus the boat trip to Japan. When I shipped the car, it had normal gas in the tank but before that winter pause, it had E85 in tank.  In any case, even if either one of those was the cause, it happened close to 6 years ago and the car has been driven something like 30 000kms after the fact. Again, apart from the plugs and the dip stick, there is nothing in the way the car runs that would indicate what has been going on in the engine. I am going to consult a shop and ask their opinion, what would be the best approach. I do have some access to a garage I could use to diagnose further myself, but time is very restrictive. Might end up buying another engine that could be used while this one is being remedied. Without pulling the head, it will be impossible to find out if it needs another bore, but here's to hoping a hone would suffice.  Goddamnit, I would really have preferred this not happening.  
    • Boot is going to be replaced eventually. I just wire brushed what I could and rust converted. Then painted in rust kill primer. the spoiler also got repainted and plugs replaced on the ends. The under side of the bonnet is going to be black also, currently white. But red on the top side, same colour code as the silo to begin.
    • Hi guys, has anyone either purchased or built themselves a rotisserie for their car before? I can only just justify the need for one hence why I should just make one but at the same time, if I make one I can kiss another 4 weeks of potentially productive car working time goodbye because I'm building a bloody rotisserie....  I mainly want it for the application of the body deadener.  Cleaning the old stuff off, priming and then colour over the deadener doesn't worry me, it's just the application using the Schutz Gun that I feel would achieve a significantly better finish painting it side on and keeping the Schutz Gun upright.  I don't think they would work well on the side let alone almost upside down for some areas.  If the product I use (Terosun, etc) could work through a HVLP ok then it might be ok to apply without the rotisserie.   I can get one of these style ones for about $1200 which is pretty good value-     I reckon if I made one it would cost around $500 but it's more the time that it would take is more of a killer than the cost.  They look to hold their value pretty well second hand so I could always sell it after using it and realistically only lose $200-$300 at worst.  Or keep it and buy another project when this one finally sees the light of day... Anyone selling one...? Cheers!  
    • While it is a very nice idea to put card style AFMs into the charge pipe (post intercooler, obviously), the position of the AFM and the recirc valve relative to each other starts to become something that you really have to consider. The situation: The stock AFM is located upstream the turbo, and the recirc valve return is located between the AFM and the turbo inlet, aimed at the turbo inlet, so that it flows away from and not through the AFM. Thus, once metered air is not metered again, neither flowing forwards, or backwards, when vented out of the charge pipe. When you put the AFM between the turbo outlet and the TB, there is a volume of pressurised charge pipe upstream of the AFM and there is a volume of pressurised pipe downstream of the AFM. When the recirc valve opens and vents the charge pipe, air is going to flow from both ends of the charge pipe towards the recirc valve. If the recirc valve is in the stock location, then the section between it and the TB doesn't really matter here - you're not going to try to put the AFM in that piece of pipe. But the AFM will likely be somewhere between the intercooler and the recirc valve, So the entire charge pipe volume from that position (upstream of the AFM, back through the intercooler, to the turbo outlet) is going to flow through the AFM, get registered as combustion air, cause the ECU to fuel for it, but get dumped out of the recirc valve and you will end up with a typical BOV related rich spike. So ideally you want to put the AFM as close to the TB as possible (so, just upstream of the crossover pipe, assuming that the stock crossover is still in use, or, just before the TB if an FFP is being used) and locate the recirc valve at the turbo outlet. Recirc valve at the turbo outlet is the new normal for things like EFRs anyway. In the even of a recirc valve opening dumping all the air in the charge pipe, pretty much all of it is going to go backwards, from the TB to the recirc valve near the turbo outlet. But only a small portion of it (that between the TB and the AFM) will pass through the AFM, and it will pass through going backwards. The card style AFMs are somewhat more immune to reading flow that passes through them in reverse than older AFMs are, so you should absolutely minimise the rich pulse behaviour associated with the unavoidable outcome of having both a recirc valve and an AFM in the charge pipe.
    • Yep, in my case as soon as I started hearing weird noises I backed off the tension until it sounded normal again. Delicate balance between enough tension to avoid that cold start slip and too much damaging things.
×
×
  • Create New...