no high rpm power with gt30r

[techghost]

Guys,
i took my first run after getting gt30r with a custom manifold. i have rc750cc injectors. car idles perfectly and low end power is nice as well but after 4/5k with full throttle it feels like i'm not making any power.... feels slow. LC1 is showing the right afr's and there isnt any knock as well. boost was 1bar.

- why does it feels slow up top? feels like i'm losing power after 4.5k rpm.
- the airflow is still low around 25lbs, although i thought with a 30r i will push atleast 40+lbs, why?
my b16g was pushing 36lbs at 22psi+ easily, never checked what the flow was at 1bar but it would've been near about the same or more as 30r.

 

[Mindslayer]

Post aj log in dsmlink forum or here.

 

[techghost]

here is a log.

 

[abaum565]

1bar and gt30r = no fun. Turn the boost up, you'll start flowing more air and feeling more power. I would imagine that the turbo won't wake up til after 25psi.

Also calibrate your maf, I only see 7psi at most and you said boost is at 1bar (14.5psi). You have some calibrating to do.

 

[techghost]

i will feel power after 25psi??? no no!!! this shouldn't be. I think 30r will be in efficiency range at 1bar+
but y do i feel a power dip??

 

[abaum565]

i will feel power after 25psi??? no no!!! this shouldn't be. I think 30r will be in efficiency range at 1bar+
but y do i feel a power dip??

Please explain and provide the compressor map your are looking at.

Besides I only see a max of 7psi in that log.

 

[forcefed4]

TurboByGarrett.com - Turbo Tech103

There is a perfect example in here for you. You need more boost after you calibrate your MAF.

 

[techghost]

i dont have a map to look at, i've heard this from local tuners here. 1bar+ is from where 30r's efficiency starts.
i was at 14psi to be exact, although due to uncalibrated MAF you are seeing 7psi. but if you have a look at my afr's and timining they are spot on.

 

[RACESTAR4G63]

Biger turbo like higher boost lower and cams.but u may need 1000cc because of inj d.c

 

[techghost]

@racestar
currently my injectors are not max'd out, i will upgrade to bigger injectors once these are max'd out which currently is not my concern.

 

[abaum565]

If your maf is not calibrated and your still have good afr's then there is another problem that may show itself when you have the maf calibrated.

14psi on a gt30r is in the turbos efficiency range on a 5.0L motor, not ours. You NEED more boost.

 

[BigBeans]

If your maf is not calibrated and your still have good afr's then there is another problem that may show itself when you have the maf calibrated.

14psi on a gt30r is in the turbos efficiency range on a 5.0L motor, not ours. You NEED more boost.

Absolutely right. My 30r (FP3052) put down:

[email protected]
363@20psi (with lean cylinder, so no timing)
428@23psi

These turbos don't even start to get efficient until 18psi, with best results in the mid 20s.

Those 750s are too small. I have 880s that are at 90%. A few more mods and they're done.