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Rear mount turbo discussion
Posted: Wed May 02, 2007 3:33 pm
by RobertE
I dont have any question in particular, just more interested in learning about them... Alot of the vette owners over here and other LSx owners have started using them.
They seem pretty cool.. Keeps the extra heat out of the engine, but its more piping and such. Also have to be careful if you drive through a puddle or such, had a fellow hydro lock his engine during a hurricane a year or so ago. The only disadvantage I can think of would be drop in pressure? Apparently its not that big of a deal though..
The only thing im a bit confused on is how the oil feeds to the turbo and such?
If anyone has an information to share, I'd appreciate it.
Posted: Wed May 02, 2007 3:51 pm
by kiwicar
when you say "rear mounted" where do you mean ? back of the engine bay over the bell housing? or hanging out the boot /trunk tacked on the end of the tail pipe? or what???
Mike
Posted: Wed May 02, 2007 3:53 pm
by RobertE
kiwicar wrote:when you say "rear mounted" where do you mean ? back of the engine bay over the bell housing? or hanging out the boot /trunk tacked on the end of the tail pipe? or what???
Mike
The ones I've seen are completely out of the engine area, located near the rear end of the car.. sometimes behind the rear end, where the mufflers would be stock.
Posted: Wed May 02, 2007 3:54 pm
by chodjinn
Dont know anything about rear mounted turbos, but as for oil feeds; the oil feed for both my turbos comes from the capillary pipe on the oil pump (usually used for oil gauge I think - mine runs off the remote filter), which is then split with a brass T-piece to feed each turbo. The returns go straight back to the sump, which is a Group A jobby with the proper turbo returns.
Noticed you have a 4.9 in the 'B, got any pics/spec?
cheers
Posted: Wed May 02, 2007 4:08 pm
by ihatesissycars
Pm Stevieturbo as he's commented on these before. I think as mad and gimmicky as they sound they can be made to work apparently wlthough to me they sound much like the electric superchargers, a con.
Posted: Wed May 02, 2007 5:07 pm
by RobertE
chodjinn wrote:Dont know anything about rear mounted turbos, but as for oil feeds; the oil feed for both my turbos comes from the capillary pipe on the oil pump (usually used for oil gauge I think - mine runs off the remote filter), which is then split with a brass T-piece to feed each turbo. The returns go straight back to the sump, which is a Group A jobby with the proper turbo returns.
Noticed you have a 4.9 in the 'B, got any pics/spec?
cheers
5.0, made a mistake on my signature
Pics can be found here
http://www.v-8.org.uk/forum/viewtopic.php?t=1018
It's not in the car yet.. still have to talk to the owner who has not picked up for nearly three years.... I would also like to get some wildcat heads for it, but I've not been able to locate any over here.
Posted: Wed May 02, 2007 5:09 pm
by IainB
ihatesissycars wrote:although to me they sound much like the electric superchargers, a con.
The one Ive seen on Youtube (I think) was/is a proper turbocharged unit just mounted into the rear tailpipes instead of the manifold, they arent in the same league as electric superchargers....made good bhp/torque as well.
Posted: Wed May 02, 2007 5:21 pm
by Lewis
They do work, it is quite a popular thing as well.
However, basic fluid dynamics says there must be increased lag due to the length of the piping but no one ever seems to comment on it? I guess due to the majority of them being on V8s and relatively low boost there's not much that's noticeable about that element.......
On a 'Vette.
For example!
Quite a few online reviews of these so hit google - lots out there

I'd post more but I'm off out now!
Posted: Wed May 02, 2007 5:56 pm
by kev_the_mole
Am I getting this wrong? Are the four 'exhaust' pipes connected or does the exhaust just dump out of the big pipe on the other end of the turbo from the inlet with the cone filter?
Answers on a postcard please, to "Is it Chavtastic?", PO Box 999, SW1 99R
Posted: Wed May 02, 2007 6:07 pm
by RobertE
kev_the_mole wrote:Am I getting this wrong? Are the four 'exhaust' pipes connected or does the exhaust just dump out of the big pipe on the other end of the turbo from the inlet with the cone filter?
Answers on a postcard please, to "Is it Chavtastic?", PO Box 999, SW1 99R
I cant see it due to filters but if its the standard sts vette setup, the tailpipes are more of less to keep the look, and that pipe is the wastegate.
As far as lag goes... I'm pretty sure they dont run as big of tubos, and dont aim for insane numbers. I've seen a lot of the vettes put out 600-700 on low boost.
It's an intresting prospect, especially on an mg-b where a front mount is out of the question... would still need to mount an air-to-air intercooler somewhere.
Posted: Wed May 02, 2007 7:38 pm
by katanaman
Interesting idea I can feel a google coming on. Looks to me like the four pipes are the waste gate, bit chav to me

Posted: Wed May 02, 2007 9:44 pm
by bill shurvinton
From a packaging perspective they can help when the engine bay is crowded.
From a thermodynamics perspective they suck. Turbos need heat to operate (as much of the shaft power comes from heat as mass flow). Most of that heat gets lost on the way to the back.
Suspect it can't do much good to fuel temperature either.
Posted: Thu May 03, 2007 10:18 am
by chodjinn
"It's an intresting prospect, especially on an mg-b where a front mount is out of the question... would still need to mount an air-to-air intercooler somewhere."
Beg to differ. I have two turbos and a large cosworth intercooler in the engine bay of my MGB and they fit no worries. Only requierd a bit of fettling to the inner wings.
Posted: Thu May 03, 2007 10:33 am
by stevieturbo
Id say ambient temps in soaring heat would do more damage to fuel temps, as well as high flow fuel systems, than a turbo under there.
Squires Turbo Systems. Do a search on them.
They may not be the best option around, but they are cheap power upgrades for a simple bolt on system, that can remain emissions legal in many very strict states in the US.
So in that respect, they have some very good points.
Oil feed is easy, it just requires a long pipe.
Oil return requires a scavenge pump to return it to the engine.
As for turbo size.... you fit a turbo of suitable size to meet your power and driveability requirements. Same as with any turbocharged install.
If you want more power, go bigger, but yes, low end might suffer.
Hell, over on the turbo minis forum, there is a guy in the US who mounted a turbo under the boot of his mini !!!! It even made a little bit of power.
So its not only for big engines, but they will be less likely to suffer noticeable innefficiencys of such a setup, simply as you are starting with a bigger more powerful engine to start with.
Posted: Thu May 03, 2007 12:50 pm
by RobertE
chodjinn wrote:"It's an intresting prospect, especially on an mg-b where a front mount is out of the question... would still need to mount an air-to-air intercooler somewhere."
Beg to differ. I have two turbos and a large cosworth intercooler in the engine bay of my MGB and they fit no worries. Only requierd a bit of fettling to the inner wings.
Apologies, don't know why I typed out they were out of the question.. a guy over here has an SR20DET and has a nice setup.. I would love to see your setup though if you have any pictures, I've not been able to find many B's with turbo chargers equipped outside of that one SR20 in the states.
Edit: SR20 B'
http://www.mgexperience.net/phorum/read ... msg-517615