Remote mount turbo?

[jerd_hambone]

Originally Posted by vex

try closer to 300-400 for an engine and tranny and ecu. if you want to rebuild it yourself you can get a soft seal kit for anywhere from 300-600, apex seals for another 300.

Sorry, it's not effective. It will work, but it will not be effective. That's like saying a knife is effective at killing people during a war. Yes it will work, but it's much more effective to use an M16 or an AK, probably cheaper too... this argument seems eerily familiar....
You already have that information.

The question is really why are you so hell bent on doing a remote mount?

I'm not hell bent on doing one, I was asking if someone had done one on a rotary.

Why are you so hell bent in putting down a setup you probably have never used?

And honestly, I have not seen a TII longblock with tranny for 300-400 bucks. If you do manage to find one for that price, it will more than likely need at the least a housing and rotor.

They do seem to be very effective, although you seem to think not. Many people have run them with great results.

[vex]

Originally Posted by classicauto

I'm not aware of anyone who's done the setup on a rotary. I've seen numerous remote mount jobs on various trucks, corvettes, TA's and they all put out some nice power. And despite what you think, the one's I've seen are no slower spooling then a poorly tuned "regular" single on our cars.

That's the thing though, were not comparing a poorly tuned "regular" setup to a properly tuned remote mount. I'm comparing (at least) a properly tuned remote mount to a properly tuned "reg". Dollar for dollar it's going to be more effective to go with a "reg". That's not to say one shouldn't do a remote mount, maybe some one wants to make it appear as a sleeper and run a completely different setup (mid placed turbo, hidden intercooler, etc). I know people personally that have done remote mount turbo setups on C5's and had great results. That's not to say that it was effective. Just imagine if they would have been willing to cut the inner fenders to fit a turbo in the engine bay? What's going to be more effective? Now the C5 != S4/5 and so they'd spend more money altering their engine bay to fit the turbos which means for them it would be cheaper to do a remote mount.

IMO - it'll work. It'll work well. But it has its purpose, which is to fit a turbo or turbos where you normally can't (ever seen a C5 or C6 engine bay?) and on our cars there's plenty of real estate to fit a turbo.

I know it will work, but I doubt we'll see the gains we would if compared to a "reg" setup you know? It would be my opinion that it would cost more to do a remote mount on our cars than it would be to do a "reg".

That said though i'm all for uniqueness...with a proerply sized turbine and housing you'll have a decent setup. Plumbing, shielding, etc will take alot of thinking but it can be done.

+1

Originally Posted by jerd_hambone

I'm not hell bent on doing one, I was asking if someone had done one on a rotary.

Why are you so hell bent in putting down a setup you probably have never used?

Read above reasons.

And honestly, I have not seen a TII longblock with tranny for 300-400 bucks. If you do manage to find one for that price, it will more than likely need at the least a housing and rotor.

I have seen recently an s4 na short block for 100, an s4 tii for 150, and an s5 short block for 150. Tii tranny's can be had all day for 100-250 depending on seller. Put them on a pallet and it's 150 more to ship it to your door.

They do seem to be very effective, although you seem to think not. Many people have run them with great results.

alright enough with the semantics.

[classicauto]

Originally Posted by vex

That's the thing though, were not comparing a poorly tuned "regular" setup to a properly tuned remote mount. I'm comparing (at least) a properly tuned remote mount to a properly tuned "reg". Dollar for dollar it's going to be more effective to go with a "reg". That's not to say one shouldn't do a remote mount, maybe some one wants to make it appear as a sleeper and run a completely different setup (mid placed turbo, hidden intercooler, etc). I know people personally that have done remote mount turbo setups on C5's and had great results. That's not to say that it was effective. Just imagine if they would have been willing to cut the inner fenders to fit a turbo in the engine bay? What's going to be more effective? Now the C5 != S4/5 and so they'd spend more money altering their engine bay to fit the turbos which means for them it would be cheaper to do a remote mount.

As far as this particular facet of the debate goes:

The C5 around here running this setup puts out a little over 580whp at 6psi. Up from its previous 390-410 in with various exhaust setups (engine also had other mods). Now, if you were to put a traditional set of turbos in the engine bay, maybe it would make 600-610 at 6psi? Hard to say, but the difference is very negliable make no mistake about it. Its not like running a turbo in the rear automatically means its 50% less efficent. Either setup would be VERY comparable when you omit the install/fab headaches of doing a rear mount turbo. Shit, Randy even has EMP on his setup and 6psi of MAP there's only 6.75psi EMP which is an extremely close ratio (edit: yes clsoe ratio for "low" boost, but nonetheless.)

[jerd_hambone]

Originally Posted by vex

That's the thing though, were not comparing a poorly tuned "regular" setup to a properly tuned remote mount. I'm comparing (at least) a properly tuned remote mount to a properly tuned "reg". Dollar for dollar it's going to be more effective to go with a "reg".

I wasn't trying to make a comparison. I just wanted to see if someone had done it.

I know it will work, but I doubt we'll see the gains we would if compared to a "reg" setup you know? It would be my opinion that it would cost more to do a remote mount on our cars than it would be to do a "reg".+1

I stated that it would be an effective way of giving an NA engine a bit of extra go. I said nothing about trying to get the most power out of an NA.

I have seen recently an s4 na short block for 100, an s4 tii for 150, and an s5 short block for 150. Tii tranny's can be had all day for 100-250 depending on seller. Put them on a pallet and it's 150 more to ship it to your door.

But then what about the turbo, manifolds, wiring harness, sensors, an exhaust to mate with the turbo manifolds, TII hood for going top mount, or a big front mount?

As I said, I have never seen a TII longblock for 400 bucks.


But look at it this way. Everyone used to say there was no way of getting power out of an NA FC. Everyone said it was impossible to turbo one without it blowing up within a few hundred miles.

But people still tried it and did it successfully.

Maybe the remote mount is the same way?

[vex]

Originally Posted by jerd_hambone

I wasn't trying to make a comparison. I just wanted to see if someone had done it.

And has already been answered.

I stated that it would be an effective way of giving an NA engine a bit of extra go. I said nothing about trying to get the most power out of an NA.

But then what about the turbo, manifolds, wiring harness, sensors, an exhaust to mate with the turbo manifolds, TII hood for going top mount, or a big front mount?

Nickle and dime, nickle and dime.

But look at it this way. Everyone used to say there was no way of getting power out of an NA FC. Everyone said it was impossible to turbo one without it blowing up within a few hundred miles.

But people still tried it and did it successfully.

Maybe the remote mount is the same way?

No one's saying that it won't work. It's the difference between less effective and effective. This exact thing was covered quite in-depth on my local forum.

Link Unfortunately you need to sign up to see that. For what it's worth here are some excerpts from it:

Obviously I'm going to say I'm not a fan, but they work. For a smaller engine like I have it wouldn't make much sense, but with a large engine it is allowable to have some loss, I'm sure it's still better than a supercharger. I guess I have a hard time believing things couldn't be shifted around to put the turbo up front, but I can't really say. I don't see how you can say they're super efficient though, depending on what you mean by efficient. You lose a lot of turbine-driving energy through the exhaust piping to the turbo which means you have to size the hot side smaller than normal to get the same spool, which therefore results in a more restrictive hot side. On the other hand, people report such good results with them that I can't down them.

HPBooks has a book out called "Street Turbocharging" written by Mark Warner, P.E. and it talks about rear mount turbos in a positive way. It's a decent book.

^Drives an SVO

Exactly larger engines have less loss from flowing exhaust air back 8 feet to the rear of the car than say an itty bitty 1.6 liter honda engine that can barely displace enough to spool a turbo right off the header. About all Ill comment on the subject till the end of the month.

^did a 600whp rear mount on a Vetter (C5 I think)

And where does this pressure differential pre-turbine and post-turbine come from? It come from expansion of the gasses.

Turbines are modeled as isentropic expansion devices. The energy in the exhaust is contained in the form of kinetic, heat (thermal), and a little bit of pulsations from each cylinder. Almost all the energy comes from heat--the expansion of the hot exhaust gasses in a turbine.

So maybe the turbine doesn't "care" if it is hot or not, but the energy spinning it's wheel is coming from the heat in the exhaust. Read a thermodynamics book instead of google.

^He's just an asshole... well, a smart asshole, but an asshole none-the-less

Jebus are you really that dense? Are you really implying that we are saying that egts entering a rear mounted turbo are the same temp as air entering the engine???

air enters at say 100F, exits at 1400F. So it cools down to 400F at a rear mounted setup. Heat is still being used to spin the turbo (and yes the turbo takes advantage of expanding gasses as heat energy as you said). Heat in the exhaust drives the turbo, but it really just complements the pressure that is already there.

Fuck...come take a ride in my turbo. I can spin up the turbo on a cold engine (using your "windmill" or whatever-you-call-it joke). Heat does play a major role...I'm just saying don't discount big airflow from big engines to small rear mounted turbos to overcome a moderate heat loss in a rear-mounted setup.

^Response to asshole, but raises some points one would need to consider.

I'm aware of that Semantics Man. What I was referring to was the fact that there's still a lot of free hydrocarbons in the exhaust that continue to burn (hence heating and expanding the exhaust) even after they've exited the exhaust ports. Some cars position the turbo so close to the head that there are still lots of free hydrocarbons in the exhaust even after it passes through the turbine, especially at higher rpm. This is wasted energy. Ideally you want to give the exhaust gas enough time to burn off all those hydrocarbons (hence "fully" expanding the exhaust) but not enough time to start to cool off, so the ideal place for the turbine inlet would be the hottest part of the exhaust stream where it would have the most available energy, both thermal and kinetic.

I'm not arguing this point anyway, all I'm saying is that if you can reduce the amount of heat lost through the piping, you can reduce the amount of energy lost by moving the turbo farther downstream. The turbo still works, and works well, just not AS well as having it at the optimum position farther upstream, but it's a compromise, just like everything else.

^He was the OP

Depending on the application, there's enough exposed piping on the trip back up to the engine to sufficiently cool a moderately compressed (say sub 6 psi) air charge. Some applications (like TT rear mount vettes) use a front mount intercooler because they don't have enough pipe, and enough air flow around that pipe, to cool it, but a lot of the truck setups do because they're longer and the pipe is run usually right beside the frame rail.

^OP Again

I'd take the faster spool over the increased top end any day, but if you have >3.0L chances are you have sufficient power until the turbo spools to start with.

Just to comment on the heat issue, the fastest spooling header setup for a WRX/STi is STOCK because of it being cast iron and maintaining heat better than any of the aftermarket designs. It doesn't make quite as much power up top as the equal length designs, but is does have much better spool (read: over 500rpm compared to some of the headers). So what have we learned children? In real life, where you burn engineering textbooks, heat effects spool, not overall power output. Now everybody go throw out your tampons and move on to a different aspect of this setup.

^2007 SCCA Prosolo National Champion- D-Stock in a 2006 WRX