T04Eneedy

its lookin like 30psi is the new 19psi.lol

finally,it looks like there are more and more people steping up and going 25+psi.

ErnieT

iTrader: (2)

Don't know where you got that info, but your dead wrong. Hell, Im proof of that.

pp13bnos

iTrader: (1)

Last I heard, the motor was a Pineapple Racing engine. When I dyno'd last with my GZ LIM with a stock port engine, I too made peak rwft lbs at 7k rpms. CJ

onefastrx7

Power can be defined as air in/air out. You might be able to flow 30psi on stock ports and a GT35R, but try pushing 30psi with a GT60 Garrett... Dont get me wrong, it will still flow, but how well?

That is why I have my RE cosmo fully bridge ported for the GT4788...

onefastrx7

lol, about time...
I want to see a 20B with 40psi and a GT4788 turbo.

LUPE

Yeah, I'm going to be maxing out my HKS T51R KAI in february when Kan comes to tune it.

I doubt it will make it but I'd like to shoot for 35psi.

onefastrx7

I just talked to Masaki at Apexi USA, and he is sending an AEM 5bar map sensor to Japan for testing. so hopefully next month we will have a good calibration for the AEM 5bar map sensor.

LUPE

I already have a 4 bar that's calibrated.

enzo250

Porting(hopefully someone who knows what there doing) will allow more cfm.
More air will equal more power, especially at high boost! This is basic physics.

BTW i wasnt' aware garrett made a GT4788? Where are you getting this from?
Is it someone else selling it with a different name, because its not a true garrett if it's labeled GT4788.

They make two different GT47's, 4708 and 4718.
Also what kind of power are u trying to make?

FB II

http://www.to4r.com/turbo.php?id=4

i think the gt47 is the gt47-88mm

enzo250

so that would be 4718...

onefastrx7

The Precision Turbo Catalog call it GT4788 ( the bigger of the GT47s).
If the Garrett calls the GT42 with 102mm comp wheel a GT4202 and the GT 42 with 94mm wheel a GT4294, then a GT4708 and GT4718 means 108 and 118 compressor major. I believe the GT4708 has a 80mm compressor inducer, and the GT4718 has a 88mm inducer.
So we are referring to the same turbo.

The engine is built make 1000whp and spin to 11000rpms safely.
My goal is 800rwhp at 35psi.

I also have a D series 20B that will use the same turbo.

RX794

K, I guess I'll have to explain this properly. What I meant to say is that with PP and BP'd turbo rotaries the exhaust/intake overlap hurts performance at higher boost, a percentage of the pressurized air will make it to the exhaust during the overlap causing it not to make anymore HP at a certain point. This is the main reason most pro drag racers with forced induction(Dee, Abel, Ari, etc.) are running street ports. Porting always helps BUT its gains lessen as the engine revs faster or whenever it makes more power. Guess what I should've said is that PP and BP'ing a motor with forced induction is useless at higher boost levels, the duration of the motor will hurt HP eventually.

enzo250

What makes you think this?
First off abel is now running a bp. And he's making more power then before!

People who talk about it not working due to too much overlap usually have never tried it. this is what they read or have heard thru so and so like it's some sort of urban legend... Besides don't you think people who actually do build these motors don't try different port timings? You can control how much overlap you want by moving the ports any where you want...

We tested a pp motor and the more boost we feed it the more power it made.
Didn't seem to stop even at the higher boost levels. That is if you consider 52lbs high.

enzo250

Yeah precision puts there own numbers on it. I hate that.
I always deal with garrett direct so i never use precision labeling system.

anyhow you building a 2 rotor or 3?
800hp at 35psi on a 2 rotor is not impossible but very hard. (so a good goal i guess)
At least i think so since i couldn't do it....lol
needed just a couple more lbs to do it......