Turbo options?

[BAC5.2]

There's a few of you Turbo boys on here, and I had a question for those of you who have gone to the dark side.

What turbo did you choose, and how does it spool?

Has anyone been daring enough to attempt a twin turbo setup? Not necessarily for lotsa power, but rather for seamless spool and power delivery.

I was wondering how the EG33 would handle spinning two GT2876's. Max boost would only be around 7psi.

How much boost are you guys running on otherwise stock motors? How much power are you making?

I have no intention of turbocharging a stock internal'd motor, but I'm debating compression ratio, and which direction to go. From what I recall, the stock CR is something like 10:1 or so, and it requires premium fuel.

I am considering a turbo or a supercharged setup, where low-end torque is of the utmost importance, second only to perfect reliability.

What do you guys think?

[Crazy_pilot]

A twin turbo settup has never been successfully done in an SVX, to the best of my knowledge. It's been tried on EG33 engines in other applications, but I haven't heard of one that works. TomsSVX has probably gone the furthest in trying a twin turbo system for an SVX. *Searches for thread*

http://www.subaru-svx.net/forum/.... (http://www.subaru-svx.net/forum/showthread.php?t=28243&highlight=toms+twin+turbo)

The single turbo guys are Phast SVX and cdigerlando. They can probably answer your turbo questions better than most.

Of course, several members are running the ECUTune Stage III supercharger as well. From what I've read, if you want low end torque that's the way to go. The blower makes boost from idle, so you've always got power.

[mikecg]

As far as boost pressures go, My Stage III has been running at 9lbs with no major issues for about a year now. TomsSVX was running around 12lbs and his ring lands gave out. The only issue we're having with our setups is the breathing of the engine. The heads and cams cant scavange enough of the gasses out at higher RPMs. Our dyno graphs are a down hill slope. You can check my locker if you want to look at the dyno plots.

[BAC5.2]

Really? So a set of forged pistons and rods and I'll have a bullet proof bottom end for my application.

I'm not TOO concerned with top end power. Low end torque is more important.

The only caveat, I do not want to intercool the setup if possible. At the MOST, I want to do no more than an air-water intercooler. That's a part of the twin-turbo idea. Get two turbos pumping half as hard, and I can drop intake temps.

The SC idea is a good one, but until the kit is available with parts only, it's not an option. I must be OBD2 emissions compliant. I was planning on replacing the cams with something designed for forced-induction at some point down the line. If I could get the SC kit with just the intake manifold, the pulleys, and such, that'd be great. I would want to use the Whipple 2.3 blower though, not the Lysholm 1600AX.

I'd be happy with 300whp/300lb-ft. Ideally, I'd like to see around 450/450, but I don't think that'd jive with the daily-driver aspect. If I could make 300lb-ft from 3,000 RPM to 5,500 RPM, I'd be very happy.

What's the factory rev-limit on these engines? 6500 like most other Subaru's?

[sicksubie]

There are buys right now for the valvetrain and cams. Pistons and rods were just ordered though. You can try LAN and see if you can still get them. Yes 6500 is the rpm limit

[TomsSVX]

we are only seeing tops of 250 whp right now so reaching 300 is gonna be a tough task

Tom

[BAC5.2]

How are you stuck at 250whp? Is it an engine management issue? Stock block issue? Heads and valvetrain issue? With 3300cc's, I didn't imagine the output record was so low.

I've hit 300whp on EJ20's so many times, I've got a formula for it.

It can be done though, I'm sure of it. Smaller displacement cars have made more power out of the box. Lower compression, and a good amount of boost, and that should be the ticket.

What turbo are you running?

[TomsSVX]

no turbo... stage III supercharger... not engine management but simply lacking the proper profiles on our cams... New cams and a full engine build comming soon.

Tom

[sicksubie]

we are only seeing tops of 250 whp right now so reaching 300 is gonna be a tough task

Tom
Are you saying that 300whp is going to be tough even after the pistons, rods, P&P head, valvetrain, cams, and the S/C kit. I was hoping that with the built motors I could maybe go to 14-16lbs of boost.

[TomsSVX]

I plan on running 12psi on pump fuel and maybe 15-17 on race fuel... we should be well over the 300 wheel mark with the built motors running 12 psi

tom

[sicksubie]

I plan on running 12psi on pump fuel and maybe 15-17 on race fuel... we should be well over the 300 wheel mark with the built motors running 12 psi

tom
that is awesome...:D :D :D :D :D :D :D

[Pure_Insanity8]

As far as boost pressures go, My Stage III has been running at 9lbs with no major issues for about a year now. TomsSVX was running around 12lbs and his ring lands gave out. The only issue we're having with our setups is the breathing of the engine. The heads and cams cant scavange enough of the gasses out at higher RPMs. Our dyno graphs are a down hill slope. You can check my locker if you want to look at the dyno plots.

Jeez, you've had that in for a year already? Time goes fast.

I sure hope the new cams aren't shooting for more scavenging. Since that is what we don't want to go on with forced incuction... we need less overlap (hence less scavenging).

I hope to see these new cams and exhaust clear up the power restrictions. I would imagine 9 psi would generate around 300 whp and 12 psi making well over that, like you said, Tom.

I've actually been wondering if anyone has engine analyzer pro to test out new ideas. I just started using it for my thermodynamics class and wow does it do a good job of estimating. It usually overshoots power predictions by about 5% but it provides a great idea of what actually works and what problems you could run into with the changes made (like valve to piston clearances and detonation problems). I'd like to put the EG33 into the program but there is a lot of info I'd need.

[Phast SVX]

Jeez, you've had that in for a year already? Time goes fast.

I sure hope the new cams aren't shooting for more scavenging. Since that is what we don't want to go on with forced incuction... we need less overlap (hence less scavenging).

I hope to see these new cams and exhaust clear up the power restrictions. I would imagine 9 psi would generate around 300 whp and 12 psi making well over that, like you said, Tom.

I've actually been wondering if anyone has engine analyzer pro to test out new ideas. I just started using it for my thermodynamics class and wow does it do a good job of estimating. It usually overshoots power predictions by about 5% but it provides a great idea of what actually works and what problems you could run into with the changes made (like valve to piston clearances and detonation problems). I'd like to put the EG33 into the program but there is a lot of info I'd need.

Ive taught myself solidworks, but ive found it much more efficeint to just use basic theory and go ahead and do it.....I have no show care thats for sure but im also not looking to push 600hp

[Pure_Insanity8]

Theory works for basic and simple modifications, but changing cam profiles, pistons/rods, compression ratios, etc. to take advantage of forced induction while getting the best result (efficiency) for the work/money you're putting in... some good software sure does help. That would be why most serious engine builders use these programs. Could make the difference between 300 and 350 ponies for the same amount of money spent.

Have you driven your SVX lately? I'd love to see you make 600 hp... even if you're not looking to.:D

[BAC5.2]

If 300whp can be done at around 9psi, that sounds more like what I was thinking.

What kind of compression ratio is the built motor running?

The basic structure of the EG33 is similar to the older EJ20's, so with good pistons and rods, it should be able to undergo the pressures of the EJ20 (which, when they had a 16g on it, ran near 14psi). 14psi should make, easily, 375whp in an EG33, don't you guys think?

As far as cam profile goes, why not just copy the profiles from one of the factory DOHC turbo motors? Head and valve design is similar, so why not just have a set of cams ground to match the cams from an STi or something? Or is it not that easy?

[TomsSVX]

as far as I know we are using a very similar profile to the 300zx twin turbo motors except we are a little bigger

Tom

[cdigerlando]

I am running an a garrett T4/T3 hybrid with an AR 60 on the intake, and I forget what the exhaust is. It spools at about 3500? I too am doing a built motor. Getting blowby.

[longassname]

For a street driven SVX run a garrett gt3582r 714568-1

I put some rough #'s on the compressor map and it's obviously an excellent match all around.

http://www.ecutune.com/posts/SVX-GT3582R.gif

[longassname]

I guess I should warn that those #'s are assuming you have my cams.
and 130 degree intake temps (figuring intercooling)

For a street driven SVX run a garrett gt3582r 714568-1

I put some rough #'s on the compressor map and it's obviously an excellent match all around.

[Jade Dragon]

a little late to the thread... But, i am currently in the design stage of my Twin turbo setup. I picked up a pair of old, but still in great shape, IHI VF48s They were on the old loyale turbos. These were a good choice, in my mind, Because they were made for a 1.8, so half of ours being 1.65 it should work damn well. It shold work nicely, putting me in boost very quickly and providing just enough from each turbo to not be over working them, and still have enough left in them to go for higher boost later on. So, thats where i stand on that so far. Im looking for all the flanges and plates ill need to make them mount cleanly. And im still trying to figure out what im going to do for intercooling. Im thinking i will go with two thin sidemounts, or a thin 2-passage.


*ADD-ON*
The only problem with getting the IHI VF series turbos, they are a real PITA if not impossible to rebuild. So we shall see what happens with those

[longassname]

I don't know anything about those turbos in particular but should warn you that some of the assumptions you are making aren't exactly right. I'm not saying those turbos won't work so don't take it that way or get too scared that they won't before you look into it--just know you need to look into it further.

You need to find the compressor plots for those turbos. The compressor plot will show the pressure ratio (vertical axis) vs the flow rate (horizontal axis). When you go to twins and set them up so that each one is running off of a bank of 3 cyllinders what you are doing is cutting the flow rate you want each one to flow in half. You aren't changing the pressure ratio at all. Let's grab that 9 lb # off of the plot I calculated for the gt35 that's about a pressure ratio of 2 and there we are flowing about 40 lbs/min (that's 400hp) and say that's what you want to run on your set up. You would plot that on your compressor map at a pressure ratio of 2 and flow rate of 20.

What you will find is there are very few turbos that will work well as twins because they aren't efficient at high boost and low flow rates.

a little late to the thread... But, i am currently in the design stage of my Twin turbo setup. I picked up a pair of old, but still in great shape, IHI VF48s They were on the old loyale turbos. These were a good choice, in my mind, Because they were made for a 1.8, so half of ours being 1.65 it should work damn well. It shold work nicely, putting me in boost very quickly and providing just enough from each turbo to not be over working them, and still have enough left in them to go for higher boost later on. So, thats where i stand on that so far. Im looking for all the flanges and plates ill need to make them mount cleanly. And im still trying to figure out what im going to do for intercooling. Im thinking i will go with two thin sidemounts, or a thin 2-passage.

[Jade Dragon]

ahh i see. thanks for the info. With jsut a begining setup, i dont think it will be a problem at all because i wil be running low boost from each turbo. I dont think ill be wanting more than 10# combined to being with.

ohh... and the VF48 is also known as the VJ11

[longassname]

sounds like you are still not quite getting it...there is no combined versus not combined with twins set up the way you are talking about...

if you are running 10 lbs of boost...that isn't 5lbs from each turbo..that's 10lbs of boost. Whether you have one compressor or two compressors or however many compressors each they are all going to be pressing against 10 lbs of manifold pressure--your pressure ratio doesn't change between twins and singles, only your flow rate changes.

ahh i see. thanks for the info. With jsut a begining setup, i dont think it will be a problem at all because i wil be running low boost from each turbo. I dont think ill be wanting more than 10# combined to being with.

[Jade Dragon]

ahh, i get it now. Having only 2 hours of sleep makes me a bit slow... I need mroe caffeene.. anyway.. now that i think about it more, yeah. I did find a compressor map, however my airflow is in ft3/min.

*correction*
After doing some more digging, i found that the labels i had previously said are wrong. the turbos i got are IHI VF-7

[cdigerlando]

I'm not a mechanical engineer, I'm an environmental engineer, but commonly I deal with pumps in parallel or pumps in series. One thing you could try when you are operating two compressors in parallel is to recalculate the graph doubling the flow, and keeping the pressure constant. I don't know how applicable this is, since air is a compressable fluid, and I mainly deal with noncompressable fluids, but you could try it to get in the ballpark range of what you are looking for. That gets back to what Mike was saying, by not doubling the boost but doubling the flow.

[Jade Dragon]

i did manage to find the map for the turbos i have.

http://www.not2fast.com/turbo/maps/IHI_BRL3911_Subaru_EA82.jpg

I dont quite know how to translate all of it, but i know someone here can.

[XT6Wagon]

Very Tiny turbos. Could spool 8psi by 1,800 rpm on a 1.8L with 7.7:1 compression. Max out in the 12-13psi range, and I do mean max out. You will be pushing these turbos hard on a SVX even at 10psi. They truely are too small IMO given that you will be running them hard to get over 300 crank HP, and running a turbo hard is not a wise thing to do on a high compression motor. More over with larger turbos with larger hotsides, you could make MORE power with less stress on the motor. The Loyale turbochargers will be a huge restriction in the exhuast. To the point where external wastegates would make you more power by routing huge ammounts of exhaust past said tiny turbos.

Try a pair of stock WRX turbos first. They suck, but they go for next to free, and the better VF series turbos will bolt in when you get tired of them

[Phast SVX]

if you want two small turbos that are junkyard units, get two first gen DSM 14B turbochargers.

[cdigerlando]

Try a pair of stock WRX turbos first. They suck, but they go for next to free, and the better VF series turbos will bolt in when you get tired of them

Hey I make 266 HP to the wheels on the WRX turbo:( . Probably one would do for his SVX unmodified motor. They are cheap though. Everyone is switching them out and there are a ton of folks rebuilding them for cheap.

I would not do over 8 psi of boost anyway with the stock motor and trans. Even then you are going to need engine management and fuel injectors. Have you thought this through? Modifying an SVX is expensive, and if your engine is old it probably won't last long. You should really do an intercooler or water injection too to reduce detonation.

[XT6Wagon]

A single WRX turbo is too small for the FXT... you would be amazed at how much money Subaru put into making it work with the 2.5L engine.

The SVX really would need two of them as its flow rates is far from good enough to make it work on a single turbo setup. Though I guess you could do an asymetrical setup and only put one bank of exhaust into it to keep it from corking the exhaust and having severe surge/overspeed issues.

For me, I'm thinking if I end up with a built engine, I'm going to have to start looking at a new class of turbos than I'm used to. T4 flanged turbo will likely be what makes the numbers... Though might go with my old standby favorite... GT35R what?

[Jade Dragon]

the reason i went with such small turbos is that i would be doing 10 lbs Max. For starting i will probably be around 5. That and i wanted something that would be spining at idle, not necissarily making boost becuae of gate & valve controll. Im gonna be doing some testing with the turbos as well, seeing how much they restrict to set up my exhaust plan.

[XT6Wagon]

but see the problem is they are too small. you CAN'T just toss any old turbo on and have it work even if its small.

As I said the FXT is a clear example of a slightly too small turbo. Subaru had to do extensive tuning just to keep the turbo from blowing the engine up. The LARGER VF39 is much safer and has much less exotic tuning to make it work with the same engine.

I'm telling you the turbos you are using are boarderline too small for the engine they were on, and the SVX will run two of them harder than the EA82T did for one.

Just one of your issues will be extreme contamination of the air/fuel mixture by exhaust gasses. Misfires, phantom knock, etc will plague your experience as will low power output and high stress on the engine.

[Jade Dragon]

Well, what turbos would you recomend. I want them to spool fast, i dont need big boost.

[XT6Wagon]

Twin twinscroll turbos don't really work or I'd be advising two turbos off the 2005+ Legacy 2.0GT automatic. Smaller but good.

I'm not to up on the older turbos, but I think the VF28 or something was the smallest of the BB stock JDM ballbearing turbos.

Twin VF39's would work, but getting a bit large.

Twin stock WRX turbos won't spool that early but are nearly free if you look in the right places. Better VF series turbos will bolt in easy.

An interesting choice but going to be hard to find is the IHI turbo off a Probe/mazdaMX6 turbo from the late 80's, but again I don't like small turbos off old cars for alot of reasons.

Vary Rare, but possibly good is 87-88 Tbird turbos. Its a IHI on a T3 flange. Its smaller than the garrets on the other 2.3L SOHC fords, but makes more stock HP. Going to be a bit large, but you have huge range of upgrade options from here. Also dunno where you plan to put two turbos, but might be too large in physical size too.

On the new front, There is some newer turbos in the size range you want from Garrett that are good. Problem is that even if you manage to get them at wholesale they tend to be $500+ each new.

And as someone said there is the DSM turbos. I dunno what those are like so...

[longassname]

HA! Where? Maybe a chinese redux with some old garrett housings.

[QUOTE=XT6Wagon]
On the new front, There is some newer turbos in the size range you want from Garrett that are good. Problem is that even if you manage to get them at wholesale they tend to be $500+ each new.
QUOTE]

[longassname]

for twins:
GT2560R - 466541- 4

Don't even bother with the turbos till you build your engine though.


Well, what turbos would you recomend. I want them to spool fast, i dont need big boost.

[longassname]

if you want more than 12ish lbs then the gt2560r 707160-10
but garrett isn't currently listing it so it may not be easily getable

[XT6Wagon]

yah a couple of the Garretts in GT25 class were insane for thier compressor maps. Course I use paper worth more than garretts published compressor maps every time I spend some "quality time" with a magazine in the bathroom. Been so long since I messed with those turbos and looked in garretts cat. that I wasn't sure enough to say more.

When I got them, the GT25's were very inexpensive if you got them wholesale. My biggest problem is I'd really like a T3 flange on whatever turbo is used for twins on a motor of this size. T25 flanges make me cry.

I also laugh at the people with GT30R and GT35R... garrett itself makes better turbos, spool quicker, make more power, and have lower stress on the engine. The 30 and 35R are usualy coupled with a way too small hot side and need to be pushed super hard to get the dyno numbers the kiddies want.

Meanwhile shopping in the twinscroll diesel section you get excelent compressors, correct sized hotsides (usualy), and tough turbos. Just ah, don't run 1600F EGT's into the turbine inlet unless you like replacing turbos.

All that said, Turbo "kits" when done right is HUGE money, and might as well build the motor as its only a few hundred $$ between a correct 300whp kit and a correct 600WHP kit when starting from scratch.

[Phast SVX]

yah a couple of the Garretts in GT25 class were insane for thier compressor maps. Course I use paper worth more than garretts published compressor maps every time I spend some "quality time" with a magazine in the bathroom. Been so long since I messed with those turbos and looked in garretts cat. that I wasn't sure enough to say more.

When I got them, the GT25's were very inexpensive if you got them wholesale. My biggest problem is I'd really like a T3 flange on whatever turbo is used for twins on a motor of this size. T25 flanges make me cry.

I also laugh at the people with GT30R and GT35R... garrett itself makes better turbos, spool quicker, make more power, and have lower stress on the engine. The 30 and 35R are usualy coupled with a way too small hot side and need to be pushed super hard to get the dyno numbers the kiddies want.

Meanwhile shopping in the twinscroll diesel section you get excelent compressors, correct sized hotsides (usualy), and tough turbos. Just ah, don't run 1600F EGT's into the turbine inlet unless you like replacing turbos.

All that said, Turbo "kits" when done right is HUGE money, and might as well build the motor as its only a few hundred $$ between a correct 300whp kit and a correct 600WHP kit when starting from scratch.

I will agree with you in some areas, and disagree in others...


the 35R is a versatile product, and it does get used quite often incorrectly But you have to be kidding me, turbos are one of the biggset misunderstood items in the import world and I would lay blame accross 99% of turbocharged aftermarket kits/one off's out there. Equally as important to spool, and more commonly ignored when designing a kit, is the header design to how the system spools.

I would consider the 35r82 -1.06 to probably be the best single unit to fit on a street performance SVX on mid boost. Lan has come to the same conclusion. your only tiff could be weather the .82 or 1.06 hotside is proper. Trial and error must be done to determine that, unless your are einstein or a rocket scienetist and then no doubt you would not be trying to size a turbo on an svx.

I do not understand what you mean by garret making "better" turbos... 360 deg bb cartridges will give you the best spool possible, unless you are talking about VAT's or something rediculous like that. Its all up to the requirements of the system, more importantly the budget, as to weather it fits into your relm. I did not build my motor, and the car runs well even with my small .63 hotside hybrid. My header is properly sized, even if on the large side, and more importantly i have a good quality 38mm Tial wastgate at a proper angle in the convergence of my headers 2-1. Infact, the same design of my header is used on the Rigoli 7s drage car(yes, they use a 3-2-1 design with the stock headers off the engine as i do, only in the front feeding a Gt55)

Eitherway, saying that a proper kit costs x amount of money is rediculous. I have a complete Stainless 304, tig welded kit (including intercooler piping) made to handle the wisconsin winter and i spent less then $3M on everything. I cut costs in areas where you can, and I spent the money on the controls of the system, that will dictate wether my engine starts tomorrow. It just means you are going to have to learn how to do some things yourself, as well as seek out the help of other enthusiasts.

[XT6Wagon]

I will agree with you in some areas, and disagree in others...


the 35R is a versatile product, and it does get used quite often incorrectly But you have to be kidding me, turbos are one of the biggset misunderstood items in the import world and I would lay blame accross 99% of turbocharged aftermarket kits/one off's out there. Equally as important to spool, and more commonly ignored when designing a kit, is the header design to how the system spools.

I would consider the 35r82 -1.06 to probably be the best single unit to fit on a street performance SVX on mid boost. Lan has come to the same conclusion. your only tiff could be weather the .82 or 1.06 hotside is proper. Trial and error must be done to determine that, unless your are einstein or a rocket scienetist and then no doubt you would not be trying to size a turbo on an svx.

I do not understand what you mean by garret making "better" turbos... 360 deg bb cartridges will give you the best spool possible, unless you are talking about VAT's or something rediculous like that. Its all up to the requirements of the system, more importantly the budget, as to weather it fits into your relm. I did not build my motor, and the car runs well even with my small .63 hotside hybrid. My header is properly sized, even if on the large side, and more importantly i have a good quality 38mm Tial wastgate at a proper angle in the convergence of my headers 2-1. Infact, the same design of my header is used on the Rigoli 7s drage car(yes, they use a 3-2-1 design with the stock headers off the engine as i do, only in the front feeding a Gt55)

Eitherway, saying that a proper kit costs x amount of money is rediculous. I have a complete Stainless 304, tig welded kit (including intercooler piping) made to handle the wisconsin winter and i spent less then $3M on everything. I cut costs in areas where you can, and I spent the money on the controls of the system, that will dictate wether my engine starts tomorrow. It just means you are going to have to learn how to do some things yourself, as well as seek out the help of other enthusiasts.

Many GT35R I've seen use the GT30R hotside... with low AR. I'll agree that the 1.06 hotside on a proprer GT35R is a very good combo.. A certain company in Austrailia has done things as silly as put a GT35R into a stock IHI turbine housing. Needless to say while the dynonumbers are not bad, the drivablity is. Spools super late, powerband is very narrow, and ultra sensitive to tuning/knock issues. Put on a true GT35R and it spools far quicker and has a lovely powerband. Even the 1.06 housing spools quicker.

And I don't see how you disagree with me on a good kit costs a certan ammount of money. There is simply the parts you must have to do it right, and if you start from scratch the parts to build a proper turbo kit with a GT35R is going to be no different than a GT30R. Or nearly any other turbo you can name. Sure there is going to be some varience, but by and large a set of 6 720cc.min injectors costs the same as a set of 550. A large tial wastegate costs just a hair more than thier smaller ones. etc. Engine management is enginemanagement, you will need it for both. All I am saying is that for a given set of sources, a good kit is going to cost nearly the same regardless of power (to a point, excluding building the motor). So a junkyard 300HP kit when done right isn't going to be much different in cost than a 400 or 500HP kit. Now its true you can cut alot of corners at lower HP, but I think most know the more corners you cut to start with, the more you spend fixing stuff later.

Now I take your point that you spent a bit more than many people would to get materials that resist your climate. Which to me is only a proper thing to do. I would advise someone in AZ to spend more on intercooling and or waterinjection than someone in Seattle.

[longassname]

ahhhhhhhhhhhhhhhh I get the difference in perceptions now...
the talk about the wrong hot sides and saying gt35r instead of gt3582r makes it all clear

when xt6 says gt35r or $500 gt2560r he means those turbos people try to sell with names like the garretts.

When phil says gt3582r he means the real deal straight from garrett which obviously comes with the correct hot side for the turbo. Correct hot side for your application? Well the turbine is what it is but choosing the right ar, that's up to you. For the eg33 I'd go straight for the 1.06 but you'd probably do fine with the 0.82 too if you want earlier spool and less top end.

[XT6Wagon]

LAN, no, I meant people who would order real garretts in really bad configurations.

Its been getting alot better than the old days of AVO500's and APS POS turbos which had real garrett cores stuffed in worthless small housings.

Other cars had turbo kits made with off the shelf GT35R's compressors mated to GT30R hotsides. I think one went so far as to merge a 35R compressor with a 28RS hotside.

Might try giving the GT40R a look. I don't know that garret has formalized the designation to a single turbo instead of the 3 or 4 different ones that people would order from garrett and call a GT40R. Most I saw was a compressor slightly bigger than the GT35R and a twinscroll hotside.

I've never bought nor used a turbo from china at this time.

[XT6Wagon]

BTW, ATPTurbo.com is where I got a good many turbos back when I was sourcing parts for turbokits.

[Phast SVX]

I am confused. A GT35R is a Duel ball bearing series T3/T04S turbocharger offered by garret, with a standard T04 S Trim housing with any of the offered turbine housings, T3 flanged. Its a series of turbochargers yes, but i do not know how a dismembered Ball bearing turbocharger with differnt housings mated to it is a GT35R by anyones gauge, its just a hybrid duel BB unit.

[Nomad]

I was reading and wondered : Is 12psi super charge same power of 12psi turbo ? But , only turbo offers intercooled option ?

[longassname]

12psi is not 12psi nor 12psi nor 12psi. The mass of air pushed is what matters. Pressure is used and talked about because it's easy to measure; however, temperature has a huge effect on the mass of air that a given pressure in a given volume indicates.

12psi and below is the range where you don't really need intercooling or aftercooling. You can cool any forced induction air charge. The piece of hardware used with turbos is called and intercooler the piece of hardware used with superchargers is called an aftercooler. 6 of 1 half a dozen of the other.

If you have a system running 12psi of boost and you throw an intercooler or aftercooler on it your manifold pressures will drop. That 12 psi will be more like 8 psi. It's still pushing about the same amount of air; the air is just cooler now. So now you are making about the same power but your boost gauge shows 8 psi instead of 12.

As far as the comparisons between superchargers and turbos when not cooling the aircharge..it depends on the supercharger and turbo. A centrifugal supercharger is about the same as a turbo. A twin screw supercharger is much more efficient so the same amout of boost from a twin screw charger is more air than the same amount from a turbo or centrifugal. A roots blower is more efficient than most turbos below around 8 psi and less efficient above that. With turbos and centrifugals the efficiency varies widely depending on the matching of the turbo to the size of the engine as well. In practice it's pretty complicated.

I was reading and wondered : Is 12psi super charge same power of 12psi turbo ? But , only turbo offers intercooled option ?

[SVX_Smoke_Out]

Been awhile since i poseted but i got a few questions. So whats the deal with the rear mounted turbos think they would work good on the SVX. Only thing im not sure about is the spool is it going to be laging because of the amount of tubing to be used for a rear mount setup?

[sicksubie]

Been discussed....... not a good option

[Nomad]

ok , thanx , now im starting to understand ! :)

[XT6Wagon]

Mmm, missed the rear mount turbo question. Yes, rear mount turbos work. You are NOT going to get razor sharp response times, but you will get a good bit of extra power.

They work, and they will work well enough to blow the stock motor to pieces from too much boost/power. In someways they are safer than normal placed turbos since you typicly don't get the turbocharger "running away", or pressure spikes that can do **** like bend throttle plates. On the otherhand, lighting off a turbo such that its operating as a "jet engine" gets some stupid fast spool times and huge torque, so if you want to autoX, or break drivetrains, a close mount turbo is definitely the way to go.

However, its not that hard to use a more traditional subaru turbo position with most reasonable sized turbos, so might as well do that instead of re-inventing the wheel as it were.

[SubaruSVXCrazy]

I just jacked a stock IHI RHB5 out of an 87 GL-10. If I rebuild it, could I use it? :D

[RallyBob]

I just jacked a stock IHI RHB5 out of an 87 GL-10. If I rebuild it, could I use it? :D

On your lawnmower perhaps.....:rolleyes:

A bit too small for an SVX. Unless you run 4 of them.

[SubaruSVXCrazy]

On your lawnmower perhaps.....:rolleyes:

A bit too small for an SVX. Unless you run 4 of them.

LOL, :lol:

[TomsSVX]

On your lawnmower perhaps.....:rolleyes:

A bit too small for an SVX. Unless you run 4 of them.

LOL Eric said those exact words yesterday:lol::lol:

Tom

[Roo]

I just jacked a stock IHI RHB5 out of an 87 GL-10. If I rebuild it, could I use it? :D

On your lawnmower perhaps.....:rolleyes:

A bit too small for an SVX. Unless you run 4 of them.

Hmm, that gives me an idea...

Individual IHI RHB5 turbos...one for each cylinder!!!

:lol: