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Hi Flow Turbo Lag

Trav33

By Trav33,
in Engines & Forced Induction

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Trav33 Mentor

Trav33

Posted
Posted

I've just put a hi-flow turbo on my 33, and am experiencing a lot of lag.

I haven't had time to get a dyno-tune yet, not sure if this will reduce the lag at all?

I'm looking to install a Power FC with the Boost Controller built in, will this upgrade help to reduce turbo lag?

Thanks for any advice...

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

If your still using the stock ECU then most certainly.

The fuel/ignition maps etc are not really designed for the turbo you are using.

A full ECU/Tune will do wonders for the car... it might not fix it all, as some hi-flows are just shocking designs and the wheel choices nothing short of crap... but give the tune a go and see what come of it

SLY33 Mentor

SLY33

Posted
Posted
pre-load on the wastegate might need to be checked.

good suggestion, ive had that problem before... wastgate looked shut but was actually loose so it could open a couple mm without any boost signal.

boost and ecu should make a world of difference even if the above isnt the case.

I thought the first thing anyone would ask is what highflow is it?! :)

Trav33 Mentor

Trav33

Posted
  • Author
Posted

How can you check the pre-load on the wastegate?

It's a Sliding Performance hi-flow, journal bearing, but not that $890 special, its something Aaron has put together with much bigger compressor and exhaust wheels.

I think i should install an ECU, say the PowerFC, and install a boost controller, than take it for a tune! That should solve all my problems!

666DAN Grand Master

666DAN

Posted
Posted

Yeah if it's one of Slides it'll be fine after about 1000km of driving once the bearing has been broken in. My one was the same, massive lag, then bang to redline. After 2 weeks it had loosened up nicely :)

Don't get the car tuned until it's done this, or you'll just be wasting time and money.

cameron Mentor

cameron

Posted
Posted
the bearings need to 'wear' in?

thats pretty wierd, aren't they balanced and run up on the machine to a few thousand rpm anyway? normal hiflows don't need to be run in do they?

No highflow factory turbo should make full boost by 5000rpm, the only time i have seen that is when the wastegate flap was not fully closed as other's have mentioned wastegate preload...

You would think that alomost ever turbo would have to ware in a little bit but not enough to cause that sort of lag???

Are these turbos ball bearing?

justin911 Grand Master

justin911

Posted
Posted

on the topic of wastegates and stuff.. i got a hks 2535 with a adjustable wastegate actuator thingy i think.. in the middle of the arm theres like a bolt that you can move. if i made it tighter or looser what affect would that have on the lag / boost etc ??

cameron Mentor

cameron

Posted
Posted
on the topic of wastegates and stuff.. i got a hks 2535 with a adjustable wastegate actuator thingy i think.. in the middle of the arm theres like a bolt that you can move. if i made it tighter or looser what affect would that have on the lag / boost etc ??

Yes it is to adjust the tension on the wastegate flap...

If you extend the rod longer it will open the flap a little or depening on how much you go and it will be very slow to make boost...

If you wind the rod in past the point were its got more tension on the wastegate flap holding it closed for longer as the RPM comes up, results in higher boost level.

So the best spot is usally hold the flap closed with your hand adjusted the rod so you have to only pull it a little bit so it holds firm tension on the wastegate arm...

Than using a boost controller to adjust for more boost.

Hope that helps.

justin911 Grand Master

justin911

Posted
Posted

i remember when the turbo was off the car i couldnt move the wastegate arm thingy at all with 2 hands.. it was realy tight, if thats good or bad ?? the stock one was heaps easier, you could actualy move it

so i shorten the arm thingy to make it spool faster ?? if i play with it and my cars been tuned will it stuff up the tune ??

thanks for ur help :laugh:

Steve Grand Master

Steve

Posted
Posted

Anyone else see a problem here?

running a bigger turbo on stock management/ecu/injectors/fuel pump can be a real recipe for disaster.

Get management sorted, get it on a dyno and check your AF ratios are correct BEFORE you boost your car - unless you have enough spare cash around for a rebuild/engine swap

cameron Mentor

cameron

Posted
Posted
i remember when the turbo was off the car i couldnt move the wastegate arm thingy at all with 2 hands.. it was realy tight, if thats good or bad ?? the stock one was heaps easier, you could actualy move it

so i shorten the arm thingy to make it spool faster ?? if i play with it and my cars been tuned will it stuff up the tune ??

thanks for ur help :laugh:

What boost do you get when running just actuator?

If the wastegate flap is hard up against the back of the turbo and the arm has to be streched a little bit to hook on than thats were you want it, and thats the fastest the turbo will spool, making it tighter again will give you more boost.

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