Boost Drop At High Rpm. R33 Gtst.

[big fat paulie]

Hey guys.

I'll start with my problem.

I lose boost (i mean 0 psi, zip, nada) at 6500rpm ish most of the time. I say most of the time as once in a while it won't do it and be fine to limiter. Other times it will only lose a few psi and then kick back to 14.

So 95% Boost Drops to zero and my car loses power.

S1r33 gtst.

Mods.

Hyper gear high flow.

Project b 2 set to 14psi.

Yellow jacket coils.

Fmic.

3in tbe.

Walbro in tank.

Nistune.

Factory intake modded so it doesn't suck closed.

Tune has been looked at by 2 well known tuners and they both think its not the tune. But something else.

Now when I run the car at 10psi it doesn't seem to have the problem.

this leads me to think its in boost control.

So is there anything I should be looking at with the profec b?

Could the actuator be adjusted in any way?

Thanks peeps.

Edited August 11, 2013 by big fat paulie

[Got a Pulsar]

Factory intake moded as in, piece of pipe jammed inside?

I reckon it's this. The remaining soft bits of intake sucking shut with the extra 4psi and Turbo efficiency would likely = 0 boost.

What Filter do you have? Is it Clean / Free Flowing?

Get a Metal Intake Pipe.

[Ben C34]

The boost controller can't drop the boost any lower than wastegate pressure, which also can't be zero so can't be that. Look into your intake pipe. I know you said it was modified, but that closing shut would do what you describe.

[big fat paulie]

Ok guys. I will check the intake.

[Frosty]

yeah another vote for intake pipe sucking shut! place a steel pip inside it of do a custom intake pipe.

paint it black for sick stock look

[scotty nm35]

Definitely the lower bend on the factory intake.

[Got a Pulsar]

This guy Knows ^^^

Sounds like another job for Scotty's Customs.

[Sinista32]

one intake pipe at a time

[big fat paulie]

Thanks guys. I'll get one fabbed up.

[Blackkers]

Hey mate I have a VERY similar set up to you. infact we are the same down to the boost controller. I'm curios how much power you made on 14psi and which hypergear turbo are you running?

Making me think I should get a solid intake pipe before i get tuned on friday

[Got a Pulsar]

You should. Hypergear recommend it.

[Frosty]

any update on this? curious to see if you got it all sorted

[Blackkers]

I would like to know as well.

You wouldn't believe it today I upped my boost to about 12psi on a hypergear turbo +walbro intank +factory ecu +factory AFM (z32+nistune +z32AFM going in on friday) and guess what? Boost drop to almost 0 around 6k RPM, boosting strongly before that.

never had this problem before as I never ran this amount of boost

Obviously some kind of metal intake pipe would be the best option however I don't have enough time to get one fabricated before a tune.

My questions is: (sorry to hijack the thread)

How do the Silicone intake pipes from JustJap go? I'm shooting for around 20psi 230-240rwkw as a final goal but this week I just want a solid tune on 15psi

looking at picking this up tomorrow http://justjap.com/store/product.php?productid=17340&cat=406&page=1

Edited August 14, 2013 by Blackkers

[scotty nm35]

Lol, a silicone one is even worse than stock.

I am making a few 80mm intakes tomorrow, I can rush you one if there is time...

[Got a Pulsar]

The silicons sound better than stock but Scotty's Sound the Best.

[big fat paulie]

Sorry for the late Reply guys. I have been away with work.

Haven't touched it yet. But will be fixing it next week. I just haven't decided if I will do it of pay someone else. Feel a case of the lazys coming on.

Car made 234kw at 6400 rpm before the boost dropped. That was on 1.1 bar. (Tuned at unigroup).

I had one of those jjr silicone pipes before but it split so I put the modded one in.

Edited August 15, 2013 by big fat paulie

[big fat paulie]

Lol, a silicone one is even worse than stock.

I am making a few 80mm intakes tomorrow, I can rush you one if there is time...

Do your intakes match up to the stock airbox and how much would one cost?

[scotty nm35]

Do your intakes match up to the stock airbox and how much would one cost?

PM'd.

[FBRacing]

What I found that works for me to find vac and piping leaks:

Let the car sit at idle till warm.

Spray small amounts of carb cleaner on fittings.

Engine will shutter if you have a leak.

Only works under idle conditions since the motor is in vacuum.

Had a similar problem. Made boost and would lose it towards the top end. Not down to zero but close. All my piping is aluminum so I wasn't getting a pipe flattening. Come to find out after several hours of searching and test driving is that some how one of the IC piping ends got a small bend where it would allow it to pass by the T-Clamp and blow out. Drove me crazy how it'd only do it under hard boost. First time it did it actually made my heart drop cuz i thought i just blew my motor. Would of never found the leak till spraying that carb cleaner. Just a thought. Good luck.

[big fat paulie]

Stopped by my mates shop yesterday and by chance the topic popped up. I mentioned that myself and a few others thought it was the intake sucking closed.

An hour later I had a new intake pipe and all is sorted.

Thanks for all your help guy.