Is This Too Much Lag?

[Fat_Tony]

So would shortening the length of the actuator rod bring on boost faster or slower or neither?

Shorter = more aggressive boost control,

Too short and you'll get boost spikes.

You want the actuator to do most of the boost work and your boost controler should fine tune the last couple of psi.

If it still doesn't hold boost get a big can actuator

[rad100]

i got it from MTQ here in adelaide.. or even adelaide turbo services..

[Get EPIC]

It's funny how every workshop that i talk to deny that it would be the actuator,even though i have told them that other people with this turbo have had actuator problems.Some say that its a bigger turbo so its gonna be laggier than stock.And i point out to them that its as laggy as a 3540 and if it was so big it wouldn't take 16 psi to make 300rwhp.Then there is : i reckon your cat is blocked,but i have a test pipe on it (decat) until i get the issue sorted.So i've tried shortening the actuator rod and it feels a bit more responsive but boost just keeps climbing the higher the revs go,even with the boost tee turned all the way down.Havent had a chance to talk to MTQ yet as i work through their business hours and they dont have any wastegates on their website unless i'm looking in the wrong place.Any help on finding an actuator that will do the job would be appreciated.Cheers

[l0WRB]

your boost keeps climbing because its internal gate and your running a gutted cat.

[Get EPIC]

your boost keeps climbing because its internal gate and your running a gutted cat.

How does that work?

[Get EPIC]

your boost keeps climbing because its internal gate and your running a gutted cat.

does anybody else think this is the problem?

[T04GTR]

apexi turbos generaly like to run over 20psi to come alive

[rad100]

bearing in mind the ax53 runs the ceramic rear wheel still!

i believe mine was running out of puff around the 260rwkw @18-19psi..

the p25 rear housing is on the sorta small side..

but should have better results than this..

this is my result with the stock actuator and eboost..

[snozzle]

i will be installing the same turbo onto my car very shortly, if i get 250kw out of this thing ill be very happy anyone run this turbo with poncams?

[SimonR32]

way too much lag for the turbo, looks like your boost controller would be the first problem...

had one (snozzle now owns it I think) on my rb20 about 4 years ago. made 305rwhp on 18psi dropping off to about 15 with a turbotech boost controller and stock actuator

im pretty sure the problem with not holding boost it due to the actuator being blown open at high revs

[SimonR32]

i was also getting 15psi by 3800rpm on my rb20 on flat road in 4th gear

[Fat_Tony]

your boost keeps climbing because its internal gate and your running a gutted cat.

When you shorten the actuator and it spikes that means its not opening up enough. Need to get an upgraded actuator. Not sure what a gutted cat has to do with boost control.

[Fat_Tony]

It's funny how every workshop that i talk to deny that it would be the actuator,even though i have told them that other people with this turbo have had actuator problems.Some say that its a bigger turbo so its gonna be laggier than stock.And i point out to them that its as laggy as a 3540 and if it was so big it wouldn't take 16 psi to make 300rwhp.Then there is : i reckon your cat is blocked,but i have a test pipe on it (decat) until i get the issue sorted.So i've tried shortening the actuator rod and it feels a bit more responsive but boost just keeps climbing the higher the revs go,even with the boost tee turned all the way down.Havent had a chance to talk to MTQ yet as i work through their business hours and they dont have any wastegates on their website unless i'm looking in the wrong place.Any help on finding an actuator that will do the job would be appreciated.Cheers

That's really funny and sad at the same time. I can't beleive all the workshops you spoke to think that kind of lag is acceptable for only 300rwhp.

[l0WRB]

with a internal gated turbo, run a full exhaust with a 3" cat... set boost to 10psi... gut the cat and u watch ur 10psi spike i can garantee it.. no back pressure.. been there done it all before...dont tell me otherwise.

[Fat_Tony]

with a internal gated turbo, run a full exhaust with a 3" cat... set boost to 10psi... gut the cat and u watch ur 10psi spike i can garantee it.. no back pressure.. been there done it all before...dont tell me otherwise.

Ho does less back pressure equal more boost? I thought less back pressure will allow the wastegate to open more freely. More back presure will force it shut and spike.

[Get EPIC]

That's really funny and sad at the same time. I can't beleive all the workshops you spoke to think that kind of lag is acceptable for only 300rwhp.

Tell me about it.I mean all i wanted was a nice responsive turbo.I just hope its either the actuator or the boost controller.Im stuck with it now so i just gotta do what i can.

[RBceffy25]

with a internal gated turbo, run a full exhaust with a 3" cat... set boost to 10psi... gut the cat and u watch ur 10psi spike i can garantee it.. no back pressure.. been there done it all before...dont tell me otherwise.

Sorry to stray off topic.

I have to agree with Fat Tony.

I have RB25DET, 3" full exhaust w/gutted cat, FMIC, pod, CAI(partially blocked due to r&r) and Blitz DSBC spec R, Stock turbo and actuator. No problems at all with spiking. Just had to adjust the gain on the boost controller and away we go, quick, smooth 10psi all the way to 7000rpm.

Sounds like your problem was something like crappy boost controller maybe?

Anyway back to topic.

My advice would be to check with matty what his thoughts are. he is very good at what he does, probably the best tuner around these parts, from what i am told. But, as everyone said, sounds like actuator. Also as far as boost controllers go, get either an electronic one with dual solenoid of one of those Turbotech Boost Controllers I read so much about here at SAU.

I am thinking by using an electronic controller with gain setting features, that increasing the gain might mask your problem but then may cause boost spiking.

Thats my 2 cents! Hope it helps in some way!

[hypergear]

The only thing can affect a turbo's normal response is the wastegate flap. It will do that if not shut. So to pre-load or a stronger actuator.

Else send it in, we can engineer a rear housing for it to full boost by 3000RPM. It Just might spin its ass off. lol

[GUN_METAL_GTR32]

hay mate i had the same turbo on my built sr20 in a s14 but with a p20 housing and it made nearly the same power as that and was about the same amount of lag.

there pretty awesome turbo too bad they are discontinued

[Get EPIC]

The only thing can affect a turbo's normal response is the wastegate flap. It will do that if not shut. So to pre-load or a stronger actuator.

Else send it in, we can engineer a rear housing for it to full boost by 3000RPM. It Just might spin its ass off. lol

would the actuators you sell be suitable?