Turbo options for Built EG33

[ZephTheChef]

http://www.atpturbo.com/Merchant2/me...egory_Code=GRT

Just to give you guys a teaser of what I've got in mind for when I pick up the SVX next month...and no, I don't mean one. In the interest of cost, I may end up using a pair of e16Gs to start with...they can be had for $400 or so each and make a little more power than the GT30Rs (at the expense of spool time obviously).

Methinks an SVX needs two of those to be happy. I intend to have it done by the time the track opens, and I plan on breaking something (and it probably won't be a record)

I go to pick up the car from my Uncle in about a month (soonest I can get off work for long enough...holidays at the post office suck!), lots of pictures of the build will be provided. Goal: 500awhp (which should happen with relatively low boost with turbos that big...15psi or less I would think considering that around 19psi does that on my 8:1 3.0L in the VR-4).

I will definitely break something at those power levels, but I don't think the engine will be the weakest link (considering it will likely still be rockin' the stock auto tranny for a bit). Yeah, I know I'm insane...but at least you guys will get to laugh at me and marvel at all the pictures of the utter destruction of various stock parts.

[sicksubie]

In all seriousness go for it, but do not get discouraged. You sound like you are up for stuff breaking so I think you are prepared. Good luck....








I guess we should start a race for 400whp. See who gets there first. Then set a race for 500whp...

[ZephTheChef]

I am always amused by how well some parts that should have disintegrated long ago amazingly hold up to abuse over and over again...I'm also amused when the new, uber-expensive extra strong replacement parts end up breaking easier than the stock stuff.

I like to thrust greatness upon various cars and see how they react to it. That usually involves giving otherwise "normal" cars ridiculous amounts of horsepower. Most of the cars I mess with are on their last leg to begin with, so I like to push their limits a bit first if I'm going to be rebuilding them anyway.

[SVXRide]

I think YT and OT have proven that the piston ring lands will be the first to go...next appears to be main bearings...we'll have to see what happens with the "built" engines. My guess is that HGs will be dropping like flies (once folks get past ~25psi), even with the ARP head studs
-Bill

[cdigerlando]

Originally Posted by Phast SVX

Why is my car still running, with more boost? Before going into storage compression on all cylinders was well above maint level. You were running without software for so long.....no offense but its just not fair to make an applicable claim to all FI subarus. IF you detonate, you will break a ring land. In the case of our pistons, you are more likely to do so because it is not as strong. But to say that it was the boost that blew your crown, is ****.

One thing I would like to point out is that when I was running unmanaged, I was very careful not to push it. Besides, there have been a lot of other well managed boost failures to cause concern, besides mine. Just talk to Tom. I definitely would not have said this with one data point. I also didn't have trouble with my motor till it was managed with Tec 2. No audible detonation or sensed detonation. While I realize that detonation usually causes ring land failures, turbos usually cause detonation, or predetonation. In any event doing FI on my motor seriously reduced its life.

How many miles do you have on your turbo? Not many if I remember correctly. Also, we were pushing this on older engines. If the engine is newer, I'm sure the pistons will last longer. I think these are important points to mention to anyone who is planning FI mods, that there could be the future cost of motor work involved. Not every engine is the same exactly. So you could go for very long without having a problem while the other 80% do.

That said, I hope you do not have trouble. I'm sure your intercooler probably helps too. That is the one difference between you everyone else who has had problems. I would really like to see you get back on the road and log more miles with your setup, to see if that is the issue. It might be interesting to get some more intercooled datapoints on the stock motor before jumping to the conclusion that I just made.

[Myxalplyx]

Originally Posted by cdigerlando

That said, I hope you do not have trouble. I'm sure your intercooler probably helps too. That is the one difference between you everyone else who has had problems. I would really like to see you get back on the road and log more miles with your setup, to see if that is the issue. It might be interesting to get some more intercooled datapoints on the stock motor before jumping to the conclusion that I just made.

OMG!!! He is the only one running an intercooler on his forced induction setup? I would think that goes without saying. There is no way I would run a turbo setup on an SVX without an intercooler. I mean, I did this on my Outback but the engine hardly ever got hot since the hood scoop and passenger side hood bonnet was left open. Also, my outback starts off with cheap gas, so raising the octane and intercooling shouldn't be an issue at 5psi of boost. The SVX already is using high octane. Adding more boost with no way to cool it off is a big no-no. If you have to drive it without an intercooler, I'd say you should get higher octane and more fuel to do so.


That is backyard tuning though. You get my point though. Turbo = no on my SVX without at least a good sized intercooler.

[cdigerlando]

Originally Posted by Myxalplyx

I wish I had some experience with this on the SVX. I simply can not argue with what you have been through, You have certainly gained my respect as far as this is concerned.

As for weak pistons on Subarus in general, maybe you have a point. Weak is subjective. I can say that I have not had any problems with any of my other subarus as far as the pistons go when using forced induction and/or nitrous. Did PoweredX2 have problems with his pistons when using nitrous? I would think in some cases nitrous is even more brutal on the pistons than turbocharging.

When I say weak about subaru pistons that is mostly from my experience with other FI folks on this site and other folks from Nasioc who have also had to replace STi pistons and WRX pistons due to ring land issues. Although per cylinder, the STi and the WRX hold up well, they also run much lower compression ratios. I would say that is one of the weak links in the bottom end for the imprezas. Ring lands or the bearings. Not so much the rods.

[cdigerlando]

Originally Posted by Myxalplyx

OMG!!! He is the only one running an intercooler on his forced induction setup? I would think that goes without saying. There is no way I would run a turbo setup on an SVX without an intercooler. I mean, I did this on my Outback but the engine hardly ever got hot since the hood scoop and passenger side hood bonnet was left open. Also, my outback starts off with cheap gas, so raising the octane and intercooling shouldn't be an issue at 5psi of boost. The SVX already is using high octane. Adding more boost with no way to cool it off is a big no-no. If you have to drive it without an intercooler, I'd say you should get higher octane and more fuel to do so.


That is backyard tuning though. You get my point though. Turbo = no on my SVX without at least a good sized intercooler.

From most of the folks that I have talked to about this issue, intercooling doesn't really benifit you until you start running more boost (7-8 lbs). Think about it, the compressor has to work a bit harder (hotter) to fight the additional backpressure of the intercooler. So there is a break even point. That was why no one ran one at such low boost levels. I did install a water injection system to help with cooling though.

[cdigerlando]

Originally Posted by sicksubie

In all seriousness go for it, but do not get discouraged. You sound like you are up for stuff breaking so I think you are prepared. Good luck....








I guess we should start a race for 400whp. See who gets there first. Then set a race for 500whp...

Yes he sounds ready to deal with the car and I am not trying to discourage anyone either from pushing the stock motor. I just don't want some young person with limited funds, who needs the car to get back and forth to school, to go out and blow up his engine based on what I told them. As long as folks have the engine build contingency in mind, have the money and a daily driver to do it, I say go for it.

[ZephTheChef]

I am indeed a young person with limited funds, but this is by no means a car that I NEED to be running, nor are my funds THAT limited (considering I do everything, and I do mean everything by myself it doesn't really take all that much money even for a complete rebuild). And WTF, mates? No intercoolers? Maybe you don't realize just how hot the air gets. Hell, even my supercharged Camaro WITH a huge intercooler was still blowing pretty damn hot air (and superchargers are generally more efficient in that department than turbos).

I've got a calculator for estimated temps based on turbo efficiency and pressure...and also one for estimating how much an intercooler can cool. With 80F degree under the hood temps, on a turbo of "average" efficiency, 2000ft above sea level, you are looking at turbo outlet temperatures of around 190F. A sufficient intercooler will bring that back down to about 100F. Tell me again you don't need an intercooler at 7psi? We're talking about nearly 375 degrees at the amount of boost I'm planning on running. You can bet each turbo is going to have it's own intercooler in my setup...plus a few other little cooling tricks I've got up my sleeves.

[ZephTheChef]

Hell, plugged in the math again and even at 4psi in that same scenario you'd be looking at over 150 degrees F...that's not exactly a friendly intake temperature if you ask me.

I would agree that there is a break even point, but that point most likely occurs less than 1psi into boost in most cases. Most intercoolers result in 1 or maybe a couple psi of pressure drop, but some of that is attributed to the drop in temperature...not just the slight restriction it causes, which is negligible really.

[sicksubie]

Yeah the intake temps are nasty with the stage 3. It was estimtated that our intake temps on 12psi are about 225 degrees...

[ZephTheChef]

Originally Posted by sicksubie

In all seriousness go for it, but do not get discouraged. You sound like you are up for stuff breaking so I think you are prepared. Good luck....

I guess we should start a race for 400whp. See who gets there first. Then set a race for 500whp...

In the 3/S world we had a "9-second grand prize fund" which is consequently now the "8-second grand prize fund" which we're a whole 2 hundredths of a second away from at the moment (due to the fact none of the big boys could seem to get a clean pass before the tracks closed). Should we start some sort of prize here...maybe an 11 second fund (or 400whp) to start with? Not that we'd probably have very many donations but it would at least be something to shoot for.

[ZephTheChef]

Originally Posted by sicksubie

Yeah the intake temps are nasty with the stage 3. It was estimtated that our intake temps on 12psi are about 225 degrees...

sounds about right, I get between 210 and 250 based on a few different ambient temps.

[Phast SVX]

Chuck,

I currently have 76XX miles on my car with the turbo system over 2 1/2 years. All very hard miles, if anyone knows me(or has seen my vidoes ) I do not get the SVX out for a saturday stroll to get groceries.

I do however as you stated have a lower milage motor in my car. a perfectly running car should be the first step in anyones plunge to FI. You will have ghosts in the closet on a 150K mile motor for almost certainty. Best bet is to at the very least make sure PCV valves, compression, and all of the vacuum system is copesetic. Irreguardless of mileage we are all working with something 12 or so years old, so like Chuck said be sure you are not working from behind the line of scrimmage.

When an intercooler becomes a neccestity has EVERYTHING to do with the temperate in the engine as stated below and nothing to do with a set boost level. You and I are both running to small of a compressor housing (yours looks to be a hybrid ~.50 trim impeller housing on a .63 a/r turbine) for peak temperates in the combustion chamber at any boost level. As you stated, the intercooler does not care how much pressure you are running. If you were blowing 5psi of 250 degree air at 30,000 shaft RPMS into the engine(high heat energy, low density), the intercooler will drop that temp substantially and will drop the charge pressure slightly, but increase the charge density greatly. I can touch my intercooler piping after a beat run, anywhere after and even right next to the motor. I am almost certain that would be a third degree burn on an un-intercooled charge pipe, say a boost tube a foot down stream of the impeller. Heat broke the ring lands on your motor. above 7 or so psi of properlly dense air, you begin to work outside of the tensile pressure offsets that a pressurized charge benefits the bottom end. But i think i have rambled enough.

Anyway around it, the built motor would be the best bet for anyone wanting to make big reliable power. Isnt it always I will the drive the car as is with maybe a bit larger turbo, but I will not be dumping into the built motor. Its not worth the amount of time and money to me.