Rear mount turbo Options

[socal1200r]

Okay, had some time on my hands, and got to thinking about this, so bear with me.



On this single-tip exhaust system, wouldn't it be possible to mount a turbo at the header flange, then route the piping directly back to the throttle body, with no intercoolers? I used to have a Merkur Xr4Ti, and the turbo system in there went directly from the turbo into the TB, no intercoolers or other fancy turbo-related gizmos. I realize a setup like this wouldn't be the best type of turbo system, but is it doable?

Seems to me that with the right turbo, it should be fairly simple to do? 'Course if that causes a ripple effect, in that the stock ECU can't handle it, new injectors, fuel pump, etc. etc., it may not be worth the trouble. But in theory, I'm thinking it should be an alternative turbo solution, and much simpler to do? This would be something to increase the hp on a daily driver, not a track car for sure. Just an option to try and squeeze more hp from a 1.7.

[Mueller]

Okay, had some time on my hands, and got to thinking about this, so bear with me.



On this single-tip exhaust system, wouldn't it be possible to mount a turbo at the header flange, then route the piping directly back to the throttle body, with no intercoolers? I used to have a Merkur Xr4Ti, and the turbo system in there went directly from the turbo into the TB, no intercoolers or other fancy turbo-related gizmos. I realize a setup like this wouldn't be the best type of turbo system, but is it doable?

Seems to me that with the right turbo, it should be fairly simple to do? 'Course if that causes a ripple effect, in that the stock ECU can't handle it, new injectors, fuel pump, etc. etc., it may not be worth the trouble. But in theory, I'm thinking it should be an alternative turbo solution, and much simpler to do? This would be something to increase the hp on a daily driver, not a track car for sure. Just an option to try and squeeze more hp from a 1.7.

Not sure how an intercooler is considered "fancy", no moving parts and they are proven to work. Not many turbo cars came without them and usually the factory decided that it is worth the $50 in parts to install them a year or so after the 1st model.

Yes, the rear mounted turbo can work, it is proven in tons of installations if you searched Google.

I was all for your thread until I see "stock" ECU (IMG:style_emoticons/default/sad.gif) You might be able to tweak it as Jeff Shu(?) did years ago, but he was stubborn, smart and resourceful.

If you have the parts give it a shot, it can be done. Worse that can happen is you don't like it and return it to stock or do something different. This is one of those things that if you have to ask if it can be done, it won't be done by you.

[McMark]

Sure, it's absolutely doable. A longer post-turbo intake track will increase boost lag, but there's always a compromise. I use a K03 on my 1.7 and I like the instant boost response, plus it's small. You'd probably never guess it has a turbo because it just drives like it's a bigger engine.

[Andyrew]

Correction KO3^

Many v8's use rear mounted turbos and they run 6' of intake and exhaust track. Yes it will increase spool up, but with a turbo like a KO3 or KO4 (Small factory size turbos) you wont notice it that much.

[iamchappy]

Will work fine..

[Mark Henry]

A rear turbo at the back of the engine (like McMarks) or back of transmission?
Back of the trans runs into scavenge issues, you need a scavenge oil sump and pump and the longer intake plumbing.

McMarks solution is the better location and I'd try to run the intercooler, even if it's a small one like out of a VW Passat.

[zipedadoo]

They make a kit for the 4th gen Camaro. Basically it replaces the muffler with a turbo. They use a pump to return the oil to the oil pan. They say there is no noticeable turbo lag with all the plumbing and I think a inter-cooler is not necessary because of the extra long tubing but I don't remember.

Some of the first gen Dodge Cummins diesels didn't use a Inter-cooler. I'd try it without one. You could always add one later. You won't make as much boost but with the stock compression ratio that might be a good thing.

[McMark]

Correction KO3^

I'm glad someone's fact checking me. (IMG:style_emoticons/default/wacko.gif)

[get off my lawn]

Yes it will work, you just have to have a way to get the oil back to the sump.
Check out STS turbo systems.

http://www.superchevy.com/how-to/148-0502-...-mounted-turbo/

http://www.superchevy.com/how-to/vemp-0802...ette-turbo-kit/



BTW an intercooler doesn't do much good until the boost gets to 5 psi or so, at 7 psi is makes a LITTLE DIFFERENCE.

[get off my lawn]

BTW you can't turbo a 914.

[ottox914]

Read thru the links in my sig.

[socal1200r]

Great responses, it's definitely not a far-fetched idea. I totally forgot though about cooling the turbo. Makes sense to run a pump for the oil line, it's got a long way to go, that's for sure. Agreed that using a smaller turbo on a stock engine would be best, both from a tuning perspective and lag perspective.

As for an IC, I only mentioned running without one because it would eliminate the plumbing and mounting issues. I haven't taken a look underneath the car, but I would imagine there's room for a smaller IC, as opposed to a typical FMIC. When I had my Merkur, which didn't have an IC, I added one from a 1991 Saab 900 turbo I used to have (installed an FMIC on that car). Put it right where the stock airbox was, which was in the engine compartment. But I figured even that IC would be better than not having one at all, and it was fairly simple to install and plumb the pipes.

Anyway, thanks for the responses!

[Mueller]

Great responses, it's definitely not a far-fetched idea. I totally forgot though about cooling the turbo. Makes sense to run a pump for the oil line, it's got a long way to go, that's for sure. Agreed that using a smaller turbo on a stock engine would be best, both from a tuning perspective and lag perspective.

As for an IC, I only mentioned running without one because it would eliminate the plumbing and mounting issues. I haven't taken a look underneath the car, but I would imagine there's room for a smaller IC, as opposed to a typical FMIC. When I had my Merkur, which didn't have an IC, I added one from a 1991 Saab 900 turbo I used to have (installed an FMIC on that car). Put it right where the stock airbox was, which was in the engine compartment. But I figured even that IC would be better than not having one at all, and it was fairly simple to install and plumb the pipes.

Anyway, thanks for the responses!

For the oil I don't see why you couldn't just run a standalone setup that is dedicated to the turbo only.

[Mike Bellis]

Correction KO3^

I'm glad someone's fact checking me. (IMG:style_emoticons/default/wacko.gif)

0O0O0O0O0O0O0O0O0O0O

[porschetub]

Remember that Mark has the skills to do this and more,the results aren't dramatic and he did it to prove a point ,very involved process and a lot of coin for the average DIY guy,lots of grief getting it to run and not blow it up,IMO build a big bore motor for a good power gain and sleep well at night.

[zipedadoo]

Great responses, it's definitely not a far-fetched idea. I totally forgot though about cooling the turbo. Makes sense to run a pump for the oil line, it's got a long way to go, that's for sure. Agreed that using a smaller turbo on a stock engine would be best, both from a tuning perspective and lag perspective.

As for an IC, I only mentioned running without one because it would eliminate the plumbing and mounting issues. I haven't taken a look underneath the car, but I would imagine there's room for a smaller IC, as opposed to a typical FMIC. When I had my Merkur, which didn't have an IC, I added one from a 1991 Saab 900 turbo I used to have (installed an FMIC on that car). Put it right where the stock airbox was, which was in the engine compartment. But I figured even that IC would be better than not having one at all, and it was fairly simple to install and plumb the pipes.

Anyway, thanks for the responses!

For the oil I don't see why you couldn't just run a standalone setup that is dedicated to the turbo only.

Seems to me a pump to pressurize the oil would be expensive and prone to failure and if your oil seal started leaking it wouldn't take long to drain your reservoir and destroy your turbo. Using engine oil would be much safer and cheaper IMO. (IMG:style_emoticons/default/beerchug.gif)

[iamchappy]

You run a restricted oil line to the turbo from a tee at your oil pressure sender and you can pump the oil back to the engine into the sump with a Tilton electric pump. Its nice to have the system in the back as it is easier install and easy to uninstall. With my 930 engine i have a cam driven pump that scavenges the turbo but i have used a Tilton before that.

You can see how clean the engine goes in and out out the car with the rear install.
look here...
http://www.914world.com/bbs2/index.php?sho...75381&st=80