Jump to content
SAU Community

Recommended Posts

  • Replies 45
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

It's not "boost cut". Read what has been written above again.

Posted Today, 12:15 AM

Sounds like you hit the TP cut (what others call boost cut). Running that much boost will pull enough air flow through the AFM for the ECU to freak out. Nistune allows you to push the cut point up higher, but your tuner may not have done so.

By the way, I agree that 13 psi is risky on an RB25 turbo. <--- thats ur wording there... TP cut , boost cut or whatever it is...

Edited by myRB25DETT

how much torque did u make dude? i also made low power 187rwkw on my GTT lol - same mods as u, 12psi

How much torque did I make or myRB25dett???

Mine was peak of 486 I think from memory, can't remember at what rev range though. I did lose top end power as the boost dropped in the higher rev range

How much torque did I make or myRB25dett???

Mine was peak of 486 I think from memory, can't remember at what rev range though. I did lose top end power as the boost dropped in the higher rev range

Cant remember mine.. Think below 400

Edited by myRB25DETT

Toshi had tuned mine rich (11.5 ish and drops to 11 at 7000rpm) and lots of timing rather than lean, so I had a really good torque band mid range, plus the way I've set the gain, start boost on my Greddy may have an influence how boost comes on and where it makes it's power.

it will be the boost controller, i set the cut pretty close to the set level as it seemed to have great control, id say on the highway its gettin a little creep, drop the set % down 3 or 4 points. There is a boost TP cut in the ecu but it is @ 18psi and there is ZERO chance of it getting close to that.

as for 13 psi max it is NOT an issue. as boost blleds off to about 10-11 psi from 3500rwpm on all r34's.

NO R34 has EVER made over 210rwkw on my dyno with only fmic and exhaust (more than 20 done so far), most make 190-200rwkw @ 12-13psi..... no failures as yet 3yrs on.

<--- thats ur wording there... TP cut , boost cut or whatever it is...

Yuh, but that's the point.....because it's not actually caused by boost. If you wound the boost up to 15 psi but put a 1" restriction on your exhaust, the TP cut wouldn't come in. If you ported it, bigger valves etc, you may well be able to get it to happen at 10psi.

Hey ya'll

Just had a Garrett Gt 30 turbo, 650cc injectors, Z32 airflow meter put in my R34 GTT RB25DET with other mods put in before

Greddy FMIC

Xforce exhaust system

Walbro fuel pump

Turbosmart boost controller

Nistune

Podfilter

Currently running 214rwkw or 287hp. My tuner and mechanic is Andy at Hyperdrive in Malaga W.A.

Now he came across a small issue, that prevented the engine not reaching its potential, as closely as i recall he said that while he was tuning it he had set the boost to 13 but then it would go back down to 9 then work its way back to 13. The power from the turbo doesn't kick in until bout 3000-3500rpm, and he wants it to come on in that mid range of 2000-25000rpm, so that the engine can get what he estimated which was about 310-320hp. Andys told me hes calling up the turbo and boost controller peeps to see what they say, but anyone who has dealt with Andy knows he doesn't mess around with ya car.

If anyone who knows what the issue is, or what it could possibly be let me or Andy know. Cheers

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

    • 2001 BE5D Subaru Legacy B4 RSK (3rd gen) EJ208 (pink injector) Twin Turbo 280PS 5-speed manual Full time 4WD "RSK" grade which means all of the above LQC option which means stock rear spoiler  I got it primarily to export to someone outside Japan who was interested. These BE5 Legacy B4 RSKs are going through a bit of a resurgence right know in Japan as they are one of the few cars from the "turbo, manual, RWD/4WD, 280hp gentleman's agreement era" cars that don't require stupid money to purchase. Which for some people might be a good opportunity to get as a base for restoration. If I can't find anyone to purchase it I will certainly be doing that myself over the long term. Why? Because it's properly fast in stock form, handles well enough for a GT sedan, there's still enough aftermarket and (if you can wait a while) genuine part support to make it a restoration candidate (<-- that will only get worse over time so it's a case of do it now or choose get a BL5 4th Gen). Mechanically it's fine, has only 89,200kms on the odometer. The problem with this car is that the body and exterior trims are weathered from at least the last 10 years being parked outdoors. I'm the 3rd owner, the first owner was the one that had it for 14 years and barely drove it, had a low-speed front impact (which didn't damage anything behind the radiator support) and got it fixed and sold it. The 2nd owner put most of the kms on it and parked it outside for the last 10 years, hence the door rubbers have seen better days but if you overlook those cosmetic details, it presents pretty nicely. There is some minor rust on the LH rear wheel arch which I'll have looked at too at some stage.  Also as you'd expect from a car this age, the clear top coat is gone, leaving a satin finish on the roof.  Mechanically it's fine (as you would expect from a car with less than 100K kms) but the steering does feel slightly vague around the centre position at higher speeds. So first on the list is to get the steering rack bushes looked at. There's also the Lock button on the remote which doesn't work, but the Open button does.... it means that the anti-theft system thinks it's always open? It seems like if you open the car and don't start the engine within 3 mins or so the anti-theft kicks in again without any beeps or signals. So if you got to start it after that, it won't. You have to push the open button again. That's how I understand it anyway. Just a small irritation but not a big problem to sort out. There's only one mod, the Wangan SPL muffler. Just a tad louder than stock. It's a really good mod for those who don't want to wake the neighbours but still want to hear a more prominent unequal length header EJ20 sound. Anyway I hope to get all those things done eventually, that is unless someone wanted to import it to their country from Japan (where I live). I'm open for negotiations as I really would like a Skyline... but this will definitely suffice in the meantime 🙂 *Disclaimer: This is how I picked it up from the dealer, minus the stuff on the back seat. I haven't cleaned the engine bay or done a thorough exterior clean, aside from spray painting the wipers. 
    • Wow, even with the Audi logo centre caps. I love OEM wheel mismatches. 
    • Welcome!  Can't go wrong with a Stag.
    • Looks good. Nice height.
    • Hey all, a little help from the Stagea hive mind plz.. I'm days away from buying either a 2002 Stagea 250tRS AR-X Four, premium leather, power seats and all the old switches etc that go with it, or a 2002 Stagea 250tRS VR-X Four AERO, pov pack, cloth seats etc, with coil overs, sports zorst, comes with original zorst and suspension and parts. (I think I've got the models right?) Both are VQ25DET, have 160000kms, both straight no rust both with $2000+ in recent servicing receipts, both ride on aftermarket 18" rims. The Aero has a replaced turbo as well. I like the cool factor of the Aero car but the AR-X has never been modified. Neither have been driven hardly at all in the last 5 years. Any thoughts on which one or does it come down to personal preference? davemoto 
×
×
  • Create New...