27 replies to this topic

[cradley-heathen]

i have seen other cars in mags with the turbo mounted right at the back of the car, just behind the rear bumper, and the inlet pipework going back up to the front to the carb or throttlebody.

i can certainly recal seeing a 205 gti like this, and other hot hatches, has anyone doen this with a mini or other a series engine?

apparently the inlet charge has colled significantly by the time it reaches the engine, so much so that an intercooler isnt required, and i guess it saves space in the engine bay as well as cutting down on under bonnet temperatures

what you guys think?

[Stevee]

but would it work effecited enough?

[Ethel]

There are piccies on the interweb somewhere of one bolted to the rear subframe.



This isn't the one I was thinking of, it's off 16valve minis

[cradley-heathen]

with my limited knowledge of turboness i cant see why it would work any less efficiently than having it up at the front. the full exhaust pressure is still going through the turbo regardless of if its at the front or the back im sure.

my only concern was that it may have more lag due to the length of the pipework going back up to the front to the carb, but i dont know?

otherwise i kinda think the advantages outweight the disadvantages?

[Wil_h]

The reason these systems were developed was to get around US modifications laws iirc. 'Rotary Mufflers' they were called.

Unless you have the same restrictions, or really have no room for a turbo close to the engine, I wouldn't bother. It's a compromised solution.

[TopCatCustom]

Surely if the inlet charge has time to cool by the time it gets to the front- the exhaust gas will have cooled by a massive amount too by the time it gets to the back which will majorly cut down on how effient the turbo is?

[Ethel]

It's a matter of proportion & relativity: 10-20 degrees off a 60 degree induction charge will have less effect than 40-60 degrees off the exhaust at more than 3 times the temperature. It will still have the same mass and there's only the pressure to worry about - no detonation implications, like the induction.

You could always lag it

[Wil_h]

Surely if the inlet charge has time to cool by the time it gets to the front- the exhaust gas will have cooled by a massive amount too by the time it gets to the back which will majorly cut down on how effient the turbo is?

Exactly. The heat in the charge is important to turbine efficiency. As I said, only worth doing if it's the only option.

[Dark Angel]

http://www.ststurbo.com/
I doubt they do a system for the mini, but has info on the rear mount systems.
The main reasoning is lack of space up front for a standard turbo, plus since they are added after the factory cats, they are smog legal. In the states, you are not legally allowed to move the position or change any exhaust component upstream of the cats.

[rick.spi]

Oil feed an drain would also be a bugger, there's enough space in our engine bays for many turbo positions if done smartly. can't see any great reason for doing this.

[Nic]

would prob end up being ripped off by a speed bump etc as its on a mini, I wouldn't want to put an expensive turbo and piping underneath my minis rear subby, plus where would you route the pipework? Thats oil feed and drain plus the inlet. and I believe that the garrett turbos drain via gravity how would you get the oil to flow around properly?

[Wil_h]

Whoa there, post ressurection. Oil return is easy, just use a scavange pump.

[mini_mad69]

Saw one at Riv run with an oil cooler poking out under the rear valance, couldn't you use a small electric oil pump and use the oil cooler as a sump?

[cradley-heathen]

wow this was a really old one of mine!

[cradley-heathen]

anyone had any more experience with this? any pics of the car that was at the riv run?