why is my turbo so laggy?

[kotu100]

like it says, im hitting 13psi @ 4300rpm with a master power t-64 .68ar.

but when it hits 13 it doesnt spike and stays @ 13 till i shift @ 6500.
it pulls nicely, but just takes so damn long to spool.

 

[92TealSupra]

Uhm what are your other mods. Seems like you should be able to get boost faster.

Maybe you have a boost leak somewhere?

 

[mecevans]

restrictive intake or exhaust?

 

[radiod]

I wouldn't think it would be a boost leak, otherwise you'd be running in to other problems such as boost creep/spiking, but it's worth a check. You can never be too sure.

How big is your IC and plumbing? A larger volume inside the pipes and IC does typically flow better, but it also takes longer to fill. I don't expect that to be the sole cause of the turbo lag, but it could have something to do with it.

What's your exhaust like? Are there any restrictions at all? Stuff caught or stuffed in there? My buddy's CAT was getting plugged and had problems with low boost and super horrible turbo lag, so that could be another issue.

Give us a list of mods to work off of, might give others some more ideas

 

[Mark2]

If your still running stock exhaust or downpipe that may be the issue. Sounds like a restriction as opposed to a boost leak.

 

[kotu100]

3" downpipe no cats, 3" tanabe cat-back, 550cc injectors, lex afm, afpr, safc, but i do have the stock IC and piping. i didnt think the stock piping could cause so much lag. i wont be able to get different piping for a couple weeks.... just had to pay my g/f's loan.

 

[MDCmotorsports]

What exhaust manifold are you running? Wastegate?

 

[kotu100]

ebay manifold the 321 stainless version, and 50mm knockoff hks wga.

theres pics of both in my build thread.

http://www.supramania.com/forums/showthread.php?t=99590

 

[oldsking]

Could be that wastegate talking ta ya Yeah the stock piping be a problem but not for what you are saying, bigger = better flow = more responsive boost.

Also keep in mind you have a .68 a/r hotside so you are killing top end but still it should spool faster! interesting.....

 

[kotu100]

Could be that wastegate talking ta ya Yeah the stock piping be a problem but not for what you are saying, bigger = better flow = more responsive boost.

Also keep in mind you have a .68 a/r hotside so you are killing top end but still it should spool faster! interesting.....

ya i figured it'd be the WG, im in the process of swappin out my motor mounts right now, once im done w/ that i'll start it up and crawl underneath and see if the WG is leaking. im also using a cheap MBC, think that could have anything to do w/ it?

could the fact that i dont have the boost source nipple for the WG coming off the turbo, but on the IC piping instead? i figured it wouldnt matter since that only tells it when to open.

ya i i got the .68 hotside so i can have the fastest spool possible, and it still pulls hard right till 6500, if i had a 2j with 8k redline i woulda got a .81


oh and thanks for the help so far guys! :thumbup:

 

[MDCmotorsports]

Need to see how you have your wastegate on the manifold, and then we'll go from there.

 

[Supracentral]

knockoff hks wga.

im also using a cheap MBC,

You've answered your own question.

 

[kotu100]

You've answered your own question.

how so?
theres many other out there running the same stuff and they dont have any problems. sorry i can't afford a $200 ebc, and $400 wastegate.

when you make less than $20grand a year you find ways around shit.


ran the engine and i couldnt feel any exhaust comin out the WG.

shortening my dp now so i dont scrape over everything, then i'll try running without the MBC.

 

[kotu100]

Need to see how you have your wastegate on the manifold, and then we'll go from there.

see like how? i bolted it up, manifold~gasket~sealing flange~wastegate. and its facing the fender well not the motor.

 

[empera]

I have used 2 knock off wastegates before...nothing will compare to the real thing, they are nothing but trouble.

how so?
theres many other out there running the same stuff and they dont have any problems. sorry i can't afford a $200 ebc, and $400 wastegate.

when you make less than $20grand a year you find ways around shit.


ran the engine and i couldnt feel any exhaust comin out the WG.

shortening my dp now so i dont scrape over everything, then i'll try running without the MBC.

 

[Moy]

Wouldn't changing the stock soft i/c pipes to hard pipes help his situation, since they are somewhat restrictive?

 

[MDCmotorsports]

see like how? i bolted it up, manifold~gasket~sealing flange~wastegate. and its facing the fender well not the motor.

You want help or you want to ask questions?

 

[jdub]

how so?
theres many other out there running the same stuff and they dont have any problems. sorry i can't afford a $200 ebc, and $400 wastegate.

when you make less than $20grand a year you find ways around shit.

And you get to deal with issues like this.

It's the MBC/WG combination + the turbo + the manifold + the DP you are running. Unless "many other out there running the same stuff" have the exact set-up, lag may or may not be a problem.
You simply can't make that statement and it be true.

 

[kotu100]

And you get to deal with issues like this.

It's the MBC/WG combination + the turbo + the manifold + the DP you are running. Unless "many other out there running the same stuff" have the exact set-up, lag may or may not be a problem.
You simply can't make that statement and it be true.

the turbo and manifold im using are PROVEN to work well, the DP is a 3" v-band with 3" piping, no bottlenecking. that only leaves the WG and MBC..

You want help or you want to ask questions?

i meant what part of it do you want to see, its very tight down there.


on a side note, where can i find a decent 50mm 4 bolt pattern wastegate? under $200 hopefully...

 

[jdub]

the turbo and manifold im using are PROVEN to work well, the DP is a 3" v-band with 3" piping, no bottlenecking. that only leaves the WG and MBC..

I didn't say anything you have isn't "proven"...it's the combination. A concept a lot of guys seem to have trouble with
The IC and IC piping have a huge effect as well.