Jump to content
SAU Community

Recommended Posts

hey all, as some of the tassy boys will know, im building up my hybrid 25/30DET as we speak. Now i am stumped as to what turbo to use. i am aiming for 300+rwkw and the car needs to be streetable. it prob wont be my every day car but will be driven on the road often.

so a big laggy sucker isnt really ideal for me but in saying that i dont want a turbo thats too small and has no punch.

Responsivness is prefered but would like to have a bit of punch on boost.

The engine specs are as follows:

rb30 bottom end

knife edged stock crank

shot peened standard rods with arp bolts

wisco 20 thou over pistons

acl race series bearings all rond

ported and polished rb25det head

stock cam shafts

new/upgraded springs and valves etc

after market ecu (unsure what one yet)

bosch 040

500cc injectors

z32 afm

forward facing plenum (unsure what one yet)

fmic

3.5 inch turbo back exhaust or there abouts

Now i will be chucking the turbo on a high mount manifold with an external gate and hope to run about 18 psi.

would like to hear what turbo setup you guys recomend for me as my knowledge in turbo selection is lacking lol.

cheers james

Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/
Share on other sites

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

I dont think you can go wrong with anything around the GT35 range (either a GT3540 or something slightly smaller, GT3240), they will easily give you the power you want (rated around 600-700HP) and beyond and being a 3L this gives you the displacement to spool it up quickly.

Quick edit: Just noticed you have 500cc injectors, are they actually 500cc or nismo 555cc injectors? Either way, if you want to go much over 300, say 330ish, id probably recommend 740cc injectors just so you arent running the 500cc on such a high duty cycle.

Edited by PM-R33
Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797325
Share on other sites

Just noticed you have 500cc injectors, are they actually 500cc or nismo 555cc injectors? Either way, if you want to go much over 300, say 330ish, id probably recommend 740cc injectors just so you arent running the 500cc on such a high duty cycle.

point taken.. i will look into bigger ones

Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797353
Share on other sites

to4z... bit big maybe???

i assume displacement should be quite close to 3 liters??

600x300x75 we will say for now about fmic (havnt purchased yet)

exhaust and fmic will be 2 of last things i get as i want the piping to have clear path so will install motor etc first.

Edited by tm_r33
Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797356
Share on other sites

you do know that the T04Z comes in a range of rear housing.

you would easily make good power and responds with the 63T A/R0.61 on a 3L

sorry this means not heaps to me... please elaborate in dummy language lol

Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797411
Share on other sites

what is the .61 actually a measurement of??

before this thread i was leaning toward a gt3540 and seems maybe still the way to go??

am i right inassuming .81 is a bit big if response is desired???

excuse my ignorance guys. never had to look into bigger than standard turbos before

Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797434
Share on other sites

Nope.One is a 3040 the other a 3540

3040 is about a 600hp turbo

3540 up to about 750hp depending on housings.

Wouldnt go smaller than an .82 on a RB30

so the one with the .61 is actually a gt3050 not a 3540???

and the one with .82 is the 3540???

Link to comment
https://www.sau.com.au/forums/topic/215037-what-turbo/#findComment-3797754
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

    • Thanks for the reply mate. Well I really hope its a hose then not engine out job
    • But.... the reason I want to run a 60 weight is so at 125C it has the same viscosity as a 40 weight at 100C. That's the whole reason. If the viscosity changes that much to drop oil pressure from 73psi to 36psi then that's another reason I should be running an oil that mimics the 40 weight at 100C. I have datalogs from the dyno with the oil pressure hitting 73psi at full throttle/high RPM. At the dyno the oil temp was around 100-105C. The pump has a 70psi internal relief spring. It will never go/can't go above 70psi. The GM recommendation of 6psi per 1000rpm is well under that... The oil sensor for logging in LS's is at the valley plate at the back of  the block/rear of where the heads are near the firewall. It's also where the knock sensors are which are notable for 'false knock'. I'm hoping I just didn't have enough oil up top causing some chatter instead of rods being sad (big hopium/copium I know) LS's definitely heat up the oil more than RB's do, the stock vettes for example will hit 300F(150C) in a lap or two and happily track for years and years. This is the same oil cooler that I had when I was in RB land, being the Setrab 25 row oil cooler HEL thing. I did think about putting a fan in there to pull air out more, though I don't know if that will actually help in huge load situations with lots of speed. I think when I had the auto cooler. The leak is where the block runs to the oil cooler lines, the OEM/Dash oil pressure sender is connected at that junction and is what broke. I'm actually quite curious to see how much oil in total capacity is actually left in the engine. As it currently stands I'm waiting on that bush to adapt the sender to it. The sump is still full (?) of oil and the lines and accusump have been drained, but the filter and block are off. I suspect there's maybe less than 1/2 the total capacity there should be in there. I have noticed in the past that topping up oil has improved oil pressure, as reported by the dash sensor. This is all extremely sketchy hence wanting to get it sorted out lol.
    • I neglected to respond to this previously. Get it up to 100 psi, and then you'll be OK.
    • I agree with everything else, except (and I'm rethinking this as it wasn't setup how my brain first though) if the sensor is at the end of a hose which is how it has been recommended to isolate it from vibrations, then if that line had a small hole in, I could foresee potentially (not a fluid dynamic specialist) the ability for it to see a lower pressure at the sensor. But thinking through, said sensor was in the actual block, HOWEVER it was also the sensor itself that broke, so oil pressure may not have been fully reaching the sensor still. So I'm still in my same theory.   However, I 100% would be saying COOL THE OIL DOWN if it's at 125c. That would be an epic concern of mine.   Im now thinking as you did Brad that the knock detection is likely due to the bearings giving a bit more noise as pressure dropped away. Kinkstah, drop your oil, and get a sample of it (as you're draining it) and send it off for analysis.
    • I myself AM TOTALLY UNPREPARED TO BELIEVE that the load is higher on the track than on the dyno. If it is not happening on the dyno, I cannot see it happening on the track. The difference you are seeing is because it is hot on the track, and I am pretty sure your tuner is not belting the crap out of it on teh dyno when it starts to get hot. The only way that being hot on the track can lead to real ping, that I can think of, is if you are getting more oil (from mist in the inlet tract, or going up past the oil control rings) reducing the effective octane rating of the fuel and causing ping that way. Yeah, nah. Look at this graph which I will helpfully show you zoomed back in. As an engineer, I look at the difference in viscocity at (in your case, 125°C) and say "they're all the same number". Even though those lines are not completely collapsed down onto each other, the oil grades you are talking about (40, 50 and 60) are teh top three lines (150, 220 and 320) and as far as I am concerned, there is not enough difference between them at that temperature to be meaningful. The viscosity of 60 at 125°C is teh same as 40 at 100°C. You should not operate it under high load at high temperature. That is purely because the only way they can achieve their emissions numbers is with thin-arse oil in it, so they have to tell you to put thin oil in it for the street. They know that no-one can drive the car & engine hard enough on the street to reach the operating regime that demands the actual correct oil that the engine needs on the track. And so they tell you to put that oil in for the track. Find a way to get more air into it, or, more likely, out of it. Or add a water spray for when it's hot. Or something.   As to the leak --- a small leak that cannot cause near catastrophic volume loss in a few seconds cannot cause a low pressure condition in the engine. If the leak is large enough to drop oil pressure, then you will only get one or two shots at it before the sump is drained.
×
×
  • Create New...