i have an 18g turbo with a gsr motor, stock internals.
what would be the best way to increase its efficiency and decrease its lag?
i've considered heatwrapping the downpipe, and that's about it. as you all know, the 18g is an internal wastegated turbo, so what else could i do? i don't necessarily know how to port stuff, so i can't port out the wastegate. the intake on there is a 2.5 in, but that's the biggest i can go due to space issues. i got an ETD to reduce motor shake and increase response, not necessarly decreasing lag though...

any ideas anyone?

 

there are many options you can chose from. a budget(for your goal) & parts list of what you have currently with the engine combo can help us all make a decision on which path you should choose.

 

oh right.
also, i don't know if the tune itself affects the efficiency / lag, but it was tuned on 3 exhaust leaks so maybe if the AFRs are fixed it'll help? anyway, here...

gsr motor
greddy 18g turbo
2.5 > 3in downpipe
2.5in exhaust
2.5in intake
2.25 hot / 1.75 cold IC piping
dsm 450s
aem FPR
vortech BOV (cannot recirc)

anything else?

 

were the exh leaks pre or post turbine ?

that thing should hit damn near full boost @ 4000-4500 ?

 

2 side-by-side manifold bolts were missing for the exhaust manifold.
and on the exhaust, the gasket wasn't put on properly (stupid me)

and the only reason why i'm wondering is because i wanna do some road racing this summer.

 

bump

 

when do you spool up?

 

Switch to a 3" exhaust all the way back. I'm still running the Greddy elbow along with a 2.5" downpipe and cat flared out to a 3" that dumps before it gets to the rear LCA and I make a full 10 psi by 3400 rpm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by numbnuts22715 &raquo;</TD></TR><TR><TD CLASS="quote">when do you spool up?</TD></TR></TABLE>
around 4.4k

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dartanian &raquo;</TD></TR><TR><TD CLASS="quote">Switch to a 3" exhaust all the way back. I'm still running the Greddy elbow along with a 2.5" downpipe and cat flared out to a 3" that dumps before it gets to the rear LCA and I make a full 10 psi by 3400 rpm.</TD></TR></TABLE>

so should i just get an o2 dump welded to the exhaust?
do you also have a greddy 18g?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsr x civic &raquo;</TD></TR><TR><TD CLASS="quote">
so should i just get an o2 dump welded to the exhaust?
do you also have a greddy 18g? </TD></TR></TABLE>

I would do 3" all the way back over a e-cutout.

Yeah, I have an 18G but not for long.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dartanian &raquo;</TD></TR><TR><TD CLASS="quote">

I would do 3" all the way back over a e-cutout.

Yeah, I have an 18G but not for long. </TD></TR></TABLE>

Yeah.. I dont really like the idea of an e-cutout.
3" all the way back for me, after the elbow as soon as I get enough money.

 

Fix the exhaust leaks for sure! I even had a leak on my downpipe that when I fixed the spool was faster, the boost went up without touching the boost controller to where it should be, and the car had much more power. Need to make a run at the track again Anything that effects how smooth the air is flowing in or out of the turbo (whether it be exhaust or the air you are compressing) will change how the turbo acts.

Some use smaller piping pre-intercooler, heatwrapping helps a little, nitrous helps alot on big turbos (dont have to worry about that). A larger more free flowing exhaust helps alot as well. A manual boost controller will keep the wastegate from creeping open before your boost setting is reached, which will increase spool. There are some other tricks too, including tuning tricks

 

Running a 2.5" exhaust with a tune that's for a 3" will mean you're likely running fairly rich, as much as 1.5 points richer. Running that rich can cause long-term issues with piston ring seal, and usually results in a noticable loss of power - and make lag worse.

If it was my own car, I'd first change to 2.5" coldside piping, fix ALL exhaust leaks, test the chargepipes for any leaks, maybe switch to 3" exhaust, and THEN retune it. Heatwrap will be best for keeping temps down, its a good idea esp for the summer. BTW what EMS are you running? Hondata?

 

hiprofile, i actually think it is 2.5 coldside. i measured it a few days ago when i was putting on t clamps and it was definitely bigger than 1.75
the exhaust i'm running is a greddy evo2 exhaust.
i don't drive hard everyday. i've actually stayed out of vtec for almost 2 weeks now
i'm running hondata s200b with all options.

also, about the boost controller, the internal WG spring is set at roughly 5 psi (highest i've gotten to). would i be able to turn up the boost with an MBC or do i need to adjust the spring? if i need to adjust the spring, how in the expletive do i do it? lol.

thanks for all the help guys. keep it coming

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsr x civic &raquo;</TD></TR><TR><TD CLASS="quote">hiprofile, i actually think it is 2.5 coldside. i measured it a few days ago when i was putting on t clamps and it was definitely bigger than 1.75
the exhaust i'm running is a greddy evo2 exhaust.
i don't drive hard everyday. i've actually stayed out of vtec for almost 2 weeks now
i'm running hondata s200b with all options.

also, about the boost controller, the internal WG spring is set at roughly 5 psi (highest i've gotten to). would i be able to turn up the boost with an MBC or do i need to adjust the spring? if i need to adjust the spring, how in the expletive do i do it? lol.

thanks for all the help guys. keep it coming </TD></TR></TABLE>

you can use a boost controller.

 

so the boost controller turns up the boost without adjusting the spring in the WG?

the MBC goes on the wastegate to blowoff valve vacuum line, right?

 

Basically cut the vac line going to your wastegate and install the boost controller to the 2 lines you are left with:

vac source -----[MBC] ----to wastegate

And the wastegate does not see boost until the boost reaches what the MBC is set at

 

so how exactly does a boost controller allow more boost to flow when the wastegate spring is only at 5 psi? i want to run 8 or 9 psi. i'm still deciding. i know i can't run more than 10 psi because i'm only on stock internals, so which would be better also? does that 1 psi make a difference?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gsr x civic &raquo;</TD></TR><TR><TD CLASS="quote">so how exactly does a boost controller allow more boost to flow when the wastegate spring is only at 5 psi? i want to run 8 or 9 psi. i'm still deciding. i know i can't run more than 10 psi because i'm only on stock internals, so which would be better also? does that 1 psi make a difference?

</TD></TR></TABLE>

boost controller interupts flow of engine pressure to the wastegate, and opens after a certain psi,which then flows to the wg and opens that up. thats why u can make your car boost higher than thw wg setting

 

18g is inefficient at 5 psi, or even at 8 or 9... toss it and get a super 16, or swap the manifold and turbo to garrett. My t3 super 60 gets full boost at 2000 rpm and still capable of over 350 whp...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oneludesol &raquo;</TD></TR><TR><TD CLASS="quote">18g is inefficient at 5 psi, or even at 8 or 9... toss it and get a super 16, or swap the manifold and turbo to garrett. My t3 super 60 gets full boost at 2000 rpm and still capable of over 350 whp...</TD></TR></TABLE>

That would almost be the ideal way, but for some people that isnt possible.

The 18G is working perfectly fine for me, I love what I've got.

It's also possible to keep the manifold and buy a garett turbo... gt28, gt30... Anything T25 flanged.


Modified by numbnuts22715 at 8:45 PM 7/1/2007

 

greddy turbos suck fat *****... Im sorry, I don't want to offend, and yes i did my time with a greddy turbo kit myself... TD04 sohc. they are far overpriced and do not perform even close to comparably priced garrett units. Why on earth would you want to run a turbo that spools at nearly 5k to run only 5-9 psi? I understand that cost is an issue, but I believe you could sell that mani and turbo for enough to pay for a t3 setup.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by numbnuts22715 &raquo;</TD></TR><TR><TD CLASS="quote">
It's also possible to keep the manifold and buy a greddy turbo... gt28, gt30... Anything T25 flanged.</TD></TR></TABLE>

wait, i thought the 18g was a 5 bolt flange?
so does that mean i can get any manifold that's flanged for a t25?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by oneludesol &raquo;</TD></TR><TR><TD CLASS="quote"> My t3 super 60 gets full boost at 2000 rpm and still capable of over 350 whp...</TD></TR></TABLE>

but isn't the 18g bigger than the super 60? are you using the kit it came with or do you have any other parts that help the spool?

 

If you want to decrease lag get a smaller turbocharger. Just make sure it dont run out of breath up top.

 

18g is bigger, much bigger thats why it doesnt spool until 4500+ rpm