Found this information on turbos

[steviek]

Well I was looking at forced performance 18g's just cause I have heard they are basically spool up of a 20g and power of the e316g but couldn't figure out how that could be.
So anyways Im on the FP website and look at the turbo and there is this crazy picture of compressor efficiency. Well i have no idea what its about so I decide to do some research and came up with this very helpful website.
http://www.gnttype.org/techarea/turbo/turboflow.html

Now I understand that there are significant advantages to having an 18g based on the compressor efficiency if its used above 22psi compared to the e316g. Since I use the e3 at 24 PSI and would push it more if it weren't for the damn terrible compressor efficiency causing too much heat and therefore knock I would. So now I am actually considering the 18g as a possible future upgrade. It has a much better compressor efficiency at higher rpms and it will be a direct replacement for my 16g. Of course it is only rated to 600 cfm where my 16g is 550 (400-380 hp) but I have basically made as much as I possibly can without switching to a SMIM and some injection and am making 318. I believe that if I haven't reached terminal velocity with my stock IM I can make around 350WHP with the 18g due to slightly increased CFM and lower temps (equaling more timing) due to compressor efficiency.

Let me know what you guys think? If I can find a good used one I think I am willing to switch. Considering I tried to buy that PTE 54 trim but got ripped off I am def willing to shell out some cash in the name of Horsepower.

[SilvrEclipse]

Nice find.

[kjewer1]

Is this the FP 18g with the larger turbine side? I forget the specs, but when FP enlarged the turbine side on the EVO Green the results were significant. For many years I refuse to be a FP fan boy, but since the EVO Green I've been trying more and more of their products. And after talking with them more and more, I've realized that at least two of the guys that run that place are basically geniouses. They've got this turbo thing nailed. Cams too. Etc. But I digress.

[2of9]

i too was thinking about the FP18g turbo...than i looked at the gt2860rs turbo. its the turbo off a blacktop sr20det motor aka the disco potato turbo. i was wondering if the gt28 turbos had more potential than the fp18g's...hmmm..

[steviek]

Kevin
"The turbine housing is cast pre-ported and fitted with a 34mm flapper valve. The WG passage remains stock diameter to limit blow open and boost drop off in the upper RPM. It is equipped with a 14psi wastegate actuator to further assist in hold boost to redline"

[kjewer1]

My question was around the turbine wheel, which is the big change on that turbo. The housing is pretty standard, just pre-ported before casting as it states, which is fairly insignificant in itself. The FP EVO Green used the standard EVO exhaust housing, but used a larger turbine wheel. This is why Buschur named it the BR 20g-LT, for large turbine. Moving to a more efficient turbine wheel should be better than going to a larger housing, which is pretty much guaranteed to increase lag, unlike a more efficient turbine wheel. Part of the reason the GT turbos do so well for a given airflow rating is the much improved turbine wheels. Excellent spool up, and good flow at full boost for good power to boost ratios. The motivation behind the new FP 18g was similar.