Installed gt2540r, No big power increase. Please help.

[rj240sx]

Alright, after installing a gt2540r I'm not noticing a big power increase over my old setup, which was a S-14 t-28. First setup was:

t-28
megan minifold
fmic
manual boost controller(14psi)
greddy bov
stock injectors
stock ecu(63)
3in exhaust from behind turbo elbow
Walbro 255

New setup:

gt2540r turbo
fmic
manual boost controller(14psi)
greddy bov
550cc injectors
z32 maf
tuned ecu(from car the gt2540r came off of)for 550cc inj. and z32 maf
3in exhaust, stock turbo elbow
Walbro 255

It feels like it's going to come on strong from the beginning, but under full boost, doesn't really feel all that fast. I mean it's fast. But not 280-300hp fast. Something seems wrong. I've already worked out a few bugs. I had to custom the turbo outlet to the hotpipe with an "s" shape with 2 rubber 90 degrees and a steel connector pipe and had to use hose clamps vs t-bolt. I'm suspecting leaking from there but not sure. At first when it would hit full boost it would hiccup like there was too much boost. Then I changed the spark plugs( from ngk iridium to ngk heat range7) and the problem went away. At least the one test drive I did before getting a speeding ticket. Also had to retighten turbo elbow nuts and elbow to downpipe nuts. It just insn't what I expected after installing the turbo,550cc inj. and tuned ecu. Do I just need it tuned again(I have a safc neo i'm about to install to have it dyno tuned) ?, do I need a fpr, ? I just don't understand. Please let me know what you think. Thanks

[sepulchral]

find somone with a wideband, i would also say your ecu may need to be reflashed or something

[spdfreek0o]

^^ new tune FTW! Could be tuned for different atmospheric conditions, different octane gas, any number of reasons, hook up a wideband and look at the numbers and I'm sure you'll find some spots that can be tweaked. Also an adjustable fpr wouldn't hurt.

[punxva]

also if your running the same boost then it wont do too much, it will probably just spool a little faster

[adictd2b00st]

also if your running the same boost then it wont do too much, it will probably just spool a little faster

what i was thinking too... do you have a compressor map for this turbo?

[s13gold]

did u get the other setup dyno'd...the old one...??

[Wei240]

yeah, that's why i don't get why people use tuned ecu if it's not tuned specifically for your setup, for all you know, it could be tuned for 100 octane, no cat, huge fmic, etc etc that you may not have

get a wideband tune, and i'm sure it'll be better...

and obviously check for leaks...

[rj240sx]

I didn't get the old setup tuned, but I ran a 14.0 @10 psi with a shitty launch on the t-28. I turned the boost up to 14 later and it felt a lot faster. Also, before I installed the turbo, I installed the 550cc injectors,z32 maf, and tuned ecu onto my old setup in preparation for the bigger turbo. I rode with that for about a day and the car felt noticebly faster, smoother. Also the ecu has a sticker on it that says tuned for 550cc injectors, z32 maf, redline 7800 rpm, 93 octane, no speed limit. I don't know if thats all it's tuned for but thats about all it says. I'm going to have it dyno tuned this weekend so hopefully it solves the problem. I'll post pics soon. Thanks for the help.

[nrg]

bring up the boost to 18psi. that's about where the turbo should be. :)

[rj240sx]

bring up the boost to 18psi. that's about where the turbo should be. :)
ok, i'll try that. i turned it up to 15psi yesterday, but it hiccuped when it hit full boost. i changed the spark plugs and test drove it again and it boosted to 15 no prob. only got to test that 1 time so far though. do i need a fpr boosting it that high? I think i could have a boost leak too, i'll double check. thanks

[Jesses240]

14psi is not going to be the exact same on your new turbo as it was on your old t-28 because the airflow #'s are different. Depends on the characteristics of your new turbo vs your old turbo


Also I didn't see a adjustable FPR on your list... Also Wideband o2 sensors are your friend in tuning... obviously if your rom is flashed for something specific then sounds like reflash is in order more specified to your tune

[rj240sx]

i boosted it up to 18 and it had about the same power output, just boosted to 18..i just remembered the guy i got the turbo from said the wastegate actuator(hks) was set at 14psi. could this be the problem even though i set the boost controller to 18 and my gauge read 18? im gonna adjust it next chance i get.

[nrg]

wastegate isn't a problem. your boost controller is what "tricks" the wastegate to work at 18psi. (google how boost controller and wastegate works; for more info). I think your tunning is limiting your power.

[rj240sx]

I just went to get it dyno tuned with the afc neo. They said the tuned ecu wasn't going to work with the neo bcause it was dumping to much fuel, so they used my stock ecu w/neo. Then said my boost cont. was bad, took it off, and said I needed a new wastegate actuator because the wastegate was not opening. When the car hits boost it sputters and you hear like a machine gun of backfire. So, I bought a power fc, electronic boost cont., and I'm about to get a new wastegate actuator, and install my fpr. This should fix it right? I guess I'll find out when I re-dyno in a week.

[steve shadows]

get an ecu that is tuned properly and exactly for your setup or get a Power FC and take it to a good tuner who can tune it to spec for you.

Sounds like a tuning issue to me, you cant just bolt on a turbo and expect the ecu to know and think for itself.

[s13coupedrfter]

14lbs is 14lbs no matter what turbo you have. The difference is how soon (or late) you get your 14lbs. The bigger turbos enable you to run more boost without going past the turbos efficiency range. Don't expect to have gobbs more power just because you put a bigger turbo on with the same boost setting. I learned this rule when I upgraded to my gt2871r vs t25 on my sr20. Hope this helps

[steve shadows]

14lbs is 14lbs no matter what turbo you have. The difference is how soon (or late) you get your 14lbs. The bigger turbos enable you to run more boost without going past the turbos efficiency range. Don't expect to have gobbs more power just because you put a bigger turbo on with the same boost setting. I learned this rule when I upgraded to my gt2871r vs t25 on my sr20. Hope this helps

sort of except larger compressor wheels move MORE volumetric effeciency at said rpm/boost level. Although depending on the exausting gas flow or CFM rate of your head and supporting mods it will spool accordingly. CFM FTW.

For example

Luke's car is using a custom 50 trim which I suggested and boost comes on at 3500 rpms range.

I am using a T61 which is a much larger wheel comparitively , my max output cieling with the SR is higher than his because of this but my turbo spools up later and has less low end torque, spool at 1 bar is around 4000 rpms.

[s13coupedrfter]

Well said Steve

[rj240sx]

Thanks for all your help. I'm starting to get a better understanding of the bigger turbo game. I finally said [email protected]#k it and got a power fc. should be here tomarrow. I'm hoping this will finish it off(for now). I'll dyno tune this weekend if I can get my clutch in this week. My new setup is:

FMIC, HKS bov
koyo rad
gt2540r
megan manifold
3 in turbo back exhaust
550cc inj
z32 maf
blitz dual sbc ebc(not in yet)
megan fpr
power fc(not in yet)
hks wastegate actuator
255lph walbro
Exedy stage2 clutch(not in yet)

Should be all the supporting mods i need, right? I'm not boosting or going into mid,high rpms cause i just put my fpr in and dont know my air/fuel ratio and don't want to mess anything up. running no boost controller too. Feels powerful and smooth during normal,slow driving:) Hopefully will be alright after the power fc tune.

[RBbugBITme]

A/F is going to be the same if you have the pressure set the same. You do know what fuel pressure it is set at right?
This is a classic example of buying a bunch of crap you don't know you need because you don't understand what you're doing. Sorry if I come off like an ass but "I'm just bein real son!"

[steve shadows]

wastegate isn't a problem. your boost controller is what "tricks" the wastegate to work at 18psi. (google how boost controller and wastegate works; for more info). I think your tunning is limiting your power.

internal gate is poop, it will spike or creep no matter what you do.

its not the same as a WG.

The boost controller (espeically the learning ones) like AVCR or custom programable map ones like Standalone's offer helps to reduce this type of spiking and creep to avery deminished level but it will never get close to performing with the consistancy of an external wg utilizing a valve structuring.

Am I to understand you were trying to run this turbo at 18 psi? with no proper management on pump gas?

ouch man.

Get a PFC and get it tuned accordingly dont risk your motor for short term progress or lack there of.

PS Is the a Garrett GT2540 or a HKS? thats kind of important also

[rj240sx]

PS Is the a Garrett GT2540 or a HKS? thats kind of important also[/QUOTE]

It's the garrett.

[rj240sx]

Sorry if I come off like an ass but "I'm just bein real son!"

Thats ok. I figured it out after moving the cursor over that little red dot under your screen name.:)

[rj240sx]

well i think i found the major problem. when i went to change my wastegate actuator, i found that the way it was adjusted, it was keeping the wastegate half open. so i tightened up the rod and now it runs a lot better. still needs tune, but doesn't hesitate at boost anymore:)

[rj240sx]

Yeah, it was all tuning. I had it professionally dyno tuned w/ the power fc and made 310 rwhp and 294 tq @ 1 bar. It's crazy power. i just wish full boost came on sooner. It's [email protected] and peak torque @ 4800rpms. kinda makes me want a .64 2871. but im happy with it, just gotta keep the rpms up i guess.:)