Rear Mounted Turbo.

[Mike1357]

I'm fairly certain nobody on here has done one, but has anyone considered it? Personally I think it's the best idea for our cars, especially for people that want to keep all their accessories and definitely a consideration for people with Bisi headers that want to go turbo.

Now so far the only problems I can think of:
*Space for the turbo in the rear might be limited (includes ground clearance).
*Not enough space to run all the pipes back to the engine?

Let's discuss.

[19dabeast85]

I've thought about it. People get great results out of them and there's no need for a front-mount since the aluminum charge piping cools just as well on its trip back to the front of the car. The length of the charge pipe is the same or actually less than a traditional front-mount ic setup usually.

The only lag is the time it takes the exhaust side to build pressure......supposedly not much longer than "normal" but I'm sure it has to take a bit longer than if mounted right at the manifold.

I believe it's a viable, different option, BUT there isn't room in the back of the cb7 for exhaust, turbo, and charge piping back. The only way I see it working is to build a "box" cut into the driver's side trunk floor similar to the passenger side "muffler box". Route exhaust to the driver's side and mount the turbo here with the turbo outlet heading over to a muffler in the stock location.

Have charge piping (oval shaped tubing) routed along passenger frame rail and up directly into the intake.

My wife's b20z crv has ALOT more room for a remote mount without cutting anything....

[Raf99]

I'm fairly certain nobody on here has done one, but has anyone considered it? Personally I think it's the best idea for our cars, especially for people that want to keep all their accessories and definitely a consideration for people with Bisi headers that want to go turbo.

Now so far the only problems I can think of:
*Space for the turbo in the rear might be limited (includes ground clearance).
*Not enough space to run all the pipes back to the engine?

Let's discuss.

I seen a Corvette C6 with rear turbos and the piping was crazy tight.

Agreed though, not enough room. I've had my flex pipe area bottom out before, and also my rear pipe (where it bends down to miss the rear lower suspension). I have a different setup now and things are tighter. But the center underside of the car only allows room for one pipe.

You may be able to squeeze two pipes down there for a smaller turbo setup, I'm not sure. But it would be quite the project!

(anyone have a pic of the underside of a cb7)

Non-cb7
http://www.clearimageautomotive.com/...s/P1180025.JPG

[Mike1357]

Now I'm not very familiar with forced induction in general so bear with me.

I thought there was still the need for a FMIC. I knew there'd be additional cooling from the length of pipe, but I didn't know if it'd be enough. If there's no need for an intercooler then to me that seems like another positive. No hacking of the front bumper or plastic (or whatever it is) underneath the bumper as well.

Seems Making room is the biggest road block. Couldn't we somehow make space somewhere behind the bumper (since a bumper will probably be getting hacked one way or another)? Obviously anyone running this setup would probably have to not run anything below a 2 inch drop and even then it might be a little sketchy. You could get away with somehow running the turbo in the trunk. Make for some crazy in-cabin noise though.

[19dabeast85]

You should never ever route anything with exhaust where a possible leak would go directly into the passenger compartment. There's not enough room inside the rear bumper for turbo stuff plus it'd melt the plastic. Like I said, I believe the only way on a cb7 is to hack up the spare tire compartment, essentially making the inside flat with metal and forming a cavity underneath open to the ground.....mount all the turbo goodies under there.

The charge piping cannot run in the same tunnel as the exhaust for two reasons. One, there's not enough room; two, too much heat transfer. The charge pipe will have to run along the ~2" box running the length of the car underneath the passenger seats. An option would be to run it just behind the sideskirt. It'd stick down below the skirt about 1". The charge pipe won't be larger than 2".

You don't need a fmic for a couple reasons:

1. The air filter and charge pipes are not getting heat soaked by the engine block, they will always be surrounded by ambient air.

2. The aluminum piping traveling the length of the car is supposedly just as efficient as a fmic......an fmic creates about 2-3psi drop????? Not sure on that and I'm sure it depends on alot of variables

This setup def has some advantages:

1. It puts a better front/rear balance in total weight of the car.
2. It lets the engine cooling system work better because the incoming air isn't cooling the fmic first before hitting the radiator.
3. Lets you retain an oe radiator with fans and A/C, P/S, etc.
4. As stated, the turbo starts off with much cooler air resulting in a colder air charge to the intake.
4. Keeps engine bay temps alot lower since a hot turbo isn't under there....further improving performance and reliability.
5. Much less chance of ruining your turbo setup in a fender bender.....if you're rear ended hard though you're screwed.

[drummersteve7]

the only real PITA would be the oil return.
I have thought about this, just seems like too much passage
for all piping considered.

[19dabeast85]

Might add that the remote setups utilize either an electric inline oil pump to pump oil back to the turbo and return to the oilpan OR a completely separate little oiling system with electric pump all located back with the turbo.

Another good thing about this is the oil going from engine to turbo and back cools as it flows the length of the car....cooler oil is a good thing with turbos.

[19dabeast85]

the only real PITA would be the oil return.
I have thought about this, just seems like too much passage
for all piping considered.

LOL, same time I posted about this.

I like the idea of a completely separate oiling system with a small oil-to-air cooler and like a 1qt reservoir and little electric pump doing nothing but cycling oil through the turbo. This will eliminate an engine failure from killing the turbo and blown turbo from killing the engine.

[Mike1357]

I believe the separate oil system would be better, although trying to find a place to mount an oil cooler might be tricky. You could even use different viscosity oils between your engine and your turbo (good for plenty of reasons).

A person could probably, like you said, cut out the spare tire area, weld in some sheet metal to close it up (and do away with the little POS wooden lid thing) and either build a custom box for the oil system for inside the trunk or mount it all outside in the now cleared area.

It just seems like there are so many pros for a setup like this. I'm really surprised nobody has done this yet. I like where this discussion is going.

[drummersteve7]

SPEED channel, just covered a rear mounted twin turbo setup!

on a corvette tho.

[WiKKeDV16]

ive worked on a rear mounted 350z and miata..

piping routing..install/removal.. oiling system.. its all a bitch..



kudos??

the sound of a practically no exhaust turbo out the back of a miata..
whistling at idle/cruise/wot..






we eventually went bigger turbo front mounted... wanted less lag.. more fireworks..

28psi.. stoch DOHC...

[rexload]

^that miata is sick



anyway, the reason why nobody on here has done it is because there are too many disadvantages:
- everything will have to be completely custom. you will need good welding equipment and be able to weld aluminum for your charge piping... because using a ton of couplers would just be too ghetto.
- much more time consuming to install than a front mount turbo setup. think about it - your average front mount turbo install takes roughly a full weekend by the time it is all said and done. now imagine if EVERYTHING had to be custom made. unless you have access to a fully equipped shop, you aren't getting this done in one or even two or three weekends.
- there will be no room for an exhaust = very loud car with no way to quiet it down = gets annoying when daily driving. all of your exhaust piping will be PRE-turbo, there will be no room to have an exhaust AFTER the turbo. theoretically, you could fit a muffler back there - but it would be TIGHT, not something your average joe-shmoe could fabricate.
- in those states where there is emissions inspection, it will be an automatic fail. visual inspection = fail. no room for a cat = fail. but there are ways around it obviously especially with obd1 cars... still, it is something to consider.
- too easy to damage the charge piping unless you REALLY tuck it next to the exhaust. still, when you scrape your exhaust, it is just a scratch. scrape an aluminum charge pipe and it will be dented and possibly cracked if your welds aren't perfect.
- where are you going to mount the air filter so it doesn't get super dirty? once it collects enough dirt/dust, it becomes a HUGE restriction.
- to those who said the charge piping can be run inside the car.... do you realize how much work that would be? that would take roughly a whole week of working 8hours a day to do it right. the piping will need to be completely custom. there will need to be a shield around it so the passenger doesn't step on it. the holes in the firewall and the trunk will need to be done properly or it will be noisy as hell and you will have exhaust gas entering the cabin.

[megarock15]

Solution get a wagon fab an engine bay in the back fab the suspension to run Mid engine Rear wheel drive fab up some crazy drivshaft to a single five speed. have seibon make a custom carbon fiber roof that scoops air in like a ram air effect. kind of like the bugati super sport. problem solved. jk

EDIT: hey thats a twin turbo setup one in front and one in back

[wed3k]

there's enough room in the front to mount a turbo...