good turbos for twins?

I wanna build a 355 forged 9:1 compression with cam and ported heads for a twin turbo setup...what do you all think about these turbos?

they are t-3/t-4 hybrids 57 trim ...heres all the specs
stone mountian racing turbo stage 3
TO4E turbo
3" inlet
2" outlet
.50 A/R compressor
.63 A/R turbine
.57 trim

TURBINE WHEEL:
EXDUCER: 2.48"
MAYOR : 2.89"

COMPRESSOR WHEEL :
EXDUCER: 2.07"
MAYOR : 2.36"

there pretty cheap on ebay, supposedly can make 25 psi, there made for b series hondas and similar 4 cylinders

They're very small too...borderline "cute". :lol:

I think you'd be better off with a T04B or even 60-1's.

I agree, you'll want some full T4's 60-1's sound nice. Depends on your HP and boost goals. Do tell more.

those would not be bad if they are set up right, john meany is runnign 52mm on his c4 and is making 1300hp. he went to the track on street tires and did a 11.11 at 151mph! If u know what u are doing u can make power with those. he also is runnign 18 degree heads.

this is the only article i can find now.

http://www.supercars.net/garages/ChevyRocks/1v2.html :cool:

its gonna be a street car mostly...occasional track use. i want to run on pump gas, as much psi as i can get away with. I want to shoot for at least 750 rwhp, i know there small, but with two i thought mabye...there like $250 a piece so thats why i was curious.

its gonna be a street car mostly...occasional track use. i want to run on pump gas, as much psi as i can get away with. I want to shoot for at least 750 rwhp, i know there small, but with two i thought mabye...there like $250 a piece so thats why i was curious.


john meanys car is a street car. he drive it everday in the non winter months. and pump gas. check it out.

john meanys car is a street car. he drive it everday in the non winter months. and pump gas. check it out.
Yeah that thing is sick, but i couldnt find any info on the turbos hes running...

Yeah that thing is sick, but i couldnt find any info on the turbos hes running...

He's running some kind of grand national turbo if I remeber correctly.

I personally do not see the reasoning behind running t3/t4 hybrids.

As far as packaging is concerned, the compressor housing will always be larger than the exhaust housing, so why not just run straight T4's?

I don't know anything about hybrid turbos, but if it were me, I would build the system with T4's so you could step it up in the future without rebuilding the entire system.

I just bought two master power T-70 from forcedinduction.com
I was going to go with two T4 sc-61s and he sells both and recomends the t-70 larger turbo 850hp each and is lighter then the sc-61 so spool is the same he said a little better actualy (physical dimensions is the same). He sells them all innovative, precsion, master power garret gt. He has the best prices and is a partner with pro-turbo guys.
My motor will be a 400ci dart block etc

I just bought two master power T-70 from forcedinduction.com
I was going to go with two T4 sc-61s and he sells both and recomends the t-70 larger turbo 850hp each and is lighter then the sc-61 so spool is the same he said a little better actualy (physical dimensions is the same). He sells them all innovative, precsion, master power garret gt. He has the best prices and is a partner with pro-turbo guys.
Jose is on this board. His name is JZ 1500 something.

I personally do not see the reasoning behind running t3/t4 hybrids.

As far as packaging is concerned, the compressor housing will always be larger than the exhaust housing, so why not just run straight T4's?

I don't know anything about hybrid turbos, but if it were me, I would build the system with T4's so you could step it up in the future without rebuilding the entire system.

I agree. Starting w/ a T4 flange allows you a lot more variety.

I'm just wondering about the whole "street car" thing. Is this just for puttin' around in or something that'll be raced on the street? I think a pair of T04-based turbos would make more than enuff power for the street.

First I want to say, do not buy a stone mountain turbo, they are junk. We have had many come in for rebuilds and are completely destroyed. All signs point to bad balancing.

Next like Jim mentioned, if you can squeeze them in, go with T4's. The T3/T4 hybrids will work, but why limit yourself on what turbos you can upgrade yourself to later. Don't get me wrong a well thought out hybrid can make plenty of HP.

Next, yes we have had great success with the MP T70. They are spooling extremely quick and are making some great #'s. Due to the fact they are small shaft units instead of big shaft, that is the main reason they spool as fast as the smaller units.

John meaney's car is using the PTE-52's. They are just regular 60mm units with a smaller turbine wheel.

Jose

I hate to be the bubble burster - but why not just go single? You honestly will have the same potential as a twin setup when done properly - and not only that, but packaging can be a lot easier. Can you do a well packaged twin? Sure, but sometimes the singles have advantages space wise, espicially under the hood of an lt1.

Dont buy anything Stone Mountain makes. Just dont. Aside from turbo problems, there are common wastegate failures, cracks in their headers and manifolds, and from what I've heard, customer service is either good or REALLY bad depending on your luck.

If you want to do twins - I agree with the T4 mark. A pair of T3/T4 hybrids can be cheaper, but the flange will set you back a lot...

I think the goals of the car are the first thing that needs to be decided, as that will tell you where you need to go. Then add a bit for future upgrades, because eventually once you get used to 600rwhp, you'll want more.

Then you go and drive a Hyundai and die of boredom behind the wheel. :D

the only reason i wanted to run twins is becuase those turbos were so cheap...the car will be raced, but still going to be a daily driver. A cage is goin in when the engine is out so i can be legal at the track...what turbo do i go with for a single? also, i was going with logs instead of headers...how bad will that hurt power?

I hate to be the bubble burster - but why not just go single? You honestly will have the same potential as a twin setup when done properly - and not only that, but packaging can be a lot easier. Can you do a well packaged twin? Sure, but sometimes the singles have advantages space wise, espicially under the hood of an lt1.

Dont buy anything Stone Mountain makes. Just dont. Aside from turbo problems, there are common wastegate failures, cracks in their headers and manifolds, and from what I've heard, customer service is either good or REALLY bad depending on your luck.

If you want to do twins - I agree with the T4 mark. A pair of T3/T4 hybrids can be cheaper, but the flange will set you back a lot...

I think the goals of the car are the first thing that needs to be decided, as that will tell you where you need to go. Then add a bit for future upgrades, because eventually once you get used to 600rwhp, you'll want more.

Then you go and drive a Hyundai and die of boredom behind the wheel. :D

the only reason i wanted to run twins is becuase those turbos were so cheap...the car will be raced, but still going to be a daily driver. A cage is goin in when the engine is out so i can be legal at the track...what turbo do i go with for a single? also, i was going with logs instead of headers...how bad will that hurt power?


you're gonna need a t-7X or bigger to go single, that'll run you $1200 - $1600. Singles are nice in certain setups, manditory in others. It all depends on wher you want to put them. I'll tell you its alot easier to plumb two 3" downpipes instead of one 4". And they will outflow the 4" too. It all depends on where you want to put them.

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

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.

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! :p :D

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. :D

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. :D


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 :D

After using the Aprexi S-AFC in my DSM days, the AVC-R is on the top of the list actually.
I see the advantages of the 3.23 gears for load purposes, but as much as I wanted less load in the lowest gears, by the same token the absurd load in 6th gear on the highway was the opposite side of the coin, keeping out of boost when climbing up a hill at 75mph for example...

Then there is tuning the darn car - and here's me trying to figure out how to make the stock ecu see boost more effectivly... :)

Have I said recently that you need to hurry up and get it finished so we can see the results... :p ;) :D

There's always FAST or DFI. What's a few more dollars in the grand scheme of things?