I am running a Master Power GT45 turbo. They are rated for something like 1000cfm, and I think have dynoed very well so far. I want to say Jose had a supra run one and put over 800rwhp down (or was it 900 or 1000rwhp?) Something silly. It's a decent turbo to say the least. Not ball bearing, but for the cost (UNDER $700 on a group buy to this day) it is a decent unit. The price is certainly worthwhile, and it fits a standard flange. I may upgrade - but from what I've read on the internet it will probably do exactly what I want it to.

Also IMHO and dont just listen to me, I'm running a 3" downpipe, which is a restriction. However I'm not worried about it too much as after less then 24" of 3" there will be a cutout. Power lost? Sure. A lot? Not enough for me to really get scared over. I'm more worried about other things. On the street, 40hp lost isnt worth caring when trying to get the other 600hp to hook. On the track things are different - but the extra couple tenths dont matter to me.

Logs are a downside. Aside from slower spool you will also have a less efficient turbo. Heat and pressure spool the turbine - and logs generate flow turbulence and hot spots in the log itself. Keeping the exhaust pulses seperate as long as possible also has advantages, just as long tubes have advantages over shorties or stock manifolds on a N/A setup. Though it probably wont hurt max power very much, it will hurt spool, and the two put together will loose a little bit of power. How much will depend on the setup, tuning etc. People do make great power on logs, but there are always advantages to more of a header style, downside is usually cost and packaging.

The other issue you will be running against is ground clearance if you run two downpipes, which again, you may worry about, or not. What matters to you is your call.

 

The GT45 has made close to 1000rwhp on a 2JZ.

Jose

 

But the 2jz is a totally different beast. Lets see if it happens on an engine with twice the displacement and lower boost levels.


That being said, you'll never beat the bang for the buck with a GT45. I almost bought one until I found out how big it was. The physical dimentions are HUGE. They are more based off of a large frame turbo than the midframe.

 

Yes the lower PR will lower the output of the turbo on a larger cube motor, but its still a hard unit to beat for the price.

Jose

 

you guys that are running big singels...where are you putting them? i just dont see any room for one big one...running two smaller ones is gonna be hard, but looks at least doable. the only reason i dont wanna run headers is the collector itself...can you buy one? those look pretty tough to make ...what about modifying block hugger corvette headers...cut off where the collector on that is and then turn all 4 primaries forward to the turbo...mmm so many ideas, i guess i really just need to start trying stuff and find out for myself. so now im looking for full t4's , or 60-1's ?? any other options on twins?

 

jose, what would be a good turbo for a single setup looking for around 800fwhp on an lt1? i'm on a budget but i plan to use this for a daily in the summer months and want a turbo that will last me or is a cheap/easy rebuild.

like everyone i'd rather had a smaller unit that spools fully around 3000-3500 on a 355.

so whats your opinion? what are my best options?

mike

 

For 800 fwhp the MP GT45 is a hard unit to beat. It will make plenty of power and spool pretty decent on a 355.

Jose

 

The PTK kit that I have puts its it infront of the engine on the driver's side (pretty much where a supecharger goes, but in a different orientation. That's usually a pretty decent place to stick a unit or two. Other favorites are in front and relocate the alt and/or ABS for single or twins. Jordan Musser had a setup where a single fit on the driver side up top and I think it looked pretty good. I'd do a search - there are links to pics and different installs in other threads.

 

Hey Geoff, if you dont mind me asking, what are the specs on that MP turbo you got? intake and exhaust trims.. intake and exhaust A/Rs. inlet and outlet size on the compressor... thanks

Andy

 

It has a .66A/R comp. and a 1.05A/R turbine. Compressor housing is a 4"OD inlet (anti-surge) and has a 3.25"OD Outlet (There abouts, that's from memory) Turbine housing is divided (for better or worse) in that arrangement. It fits a T4 bolt pattern and has a 4" V-Band for the downpipe.

68.9mm compressor wheel - Dont remember of the top of my head
77.5mm turbine wheel - This one is a derivative of the S4 Schwitzer/Airwerks wheel (I think)

http://www.partsexpressonline.com/images/gt45.gif

 

Geoff what size engine you have and where do you spool up at?

 

Engine is forged, .020 over. I was hoping to get the car done by Xmas and get a few passes on the dyno, but that didnt happen. This spring I will have vids of it down the track, on the dyno, more pics then you can shake a stick at, and everything to go with. (I think PTK will be happy to have me on the boards when all is said and done) The car is a "weekend racer" that will rarely see track time, and was adjusted accordingly. I wasnt too worried about max "peak hp" but rather crap loads of fun on the street.

I am hoping to never see boost till 3200rpm - but spool should start right about there, and hit max boost shortly after. It is a little slow, but that was intentional... this is a street car. Peak HP is also limited to be more usable. I dont plan on running past 6500rpm, so I wanted maximum HP right there.

 

Is that why you went with the 1.05 exhaust housing, to delay your boost threshhold until a bit higher? I kind of figured you'd go with a.96 or somewhere around there.

thanks for the info man. When I can get the funds together to do this myself, I think my goals are pretty similar to yours, so I'm real interested to see how it all works out for you. Get that thing together already!

 

Thats exactly why the 1.05 appealed to me (I was actually looking at a 1.15 at one point). I enjoy the 1st gear our cars have with the 3.42 rear end (again, not gonna drop the ratio) and revving to 2600-2700 and not spooling the turbo was a requirement. Not to mention the threshold is more sudden - meaning it's easier to predict and control, which lends a progressive boost controller even better. That should really let me know what's going to happen through the gears and dial it in for street use. So far so good. I'll be posting lots of pics and details when it's running and tuned.

 

interesting thoughts on all that...... I'm very curious to find out what kind of threshhold you end up having. When I go turbo, I too was going to stay with the 3.42s as well on my 6 speed. Hell, I hear some folks even step down to the 3.23s. What controller were you going to go with. I was thinking about the newer apexi AVCR, as it has has gear specific boost control, which I take to mean that you can control boost differently in each gear. Might be nice if you used a smaller exhaust housing to control spool and boost limits when traction is more of a concern in the lower gears