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MG MGB GT V8 Factory Originals Technical - Turbo as an Option
Some thoughts on power options on the GM V-6 (originally posted elsewhere but I thought it might be of interest here - the remote mount turbo idea would be easy to do in an MG!).
"If someone developed a kit for a turbo GM V-6 in the MGB they would probably have a market. Miller Woods did the job 15 years ago for the Fiero and the results were gratifying. Bolt the kit on a stock 2.8 and get around 210 BHP. Bolt it on an engine purpose built to take a bit higher boost (suitable cam, forged pistons, stroked to 3.1) and you can achieve 275 + BHP on the iron head versions, and 300 + on 3.4.
I ran my stock turbo for a few years before getting the bug and building a super engine (3.2) with 13 PSI boost - and that one has held up to all the abuse I could throw at it for over a decade (going on 110,000 KM on the high boost engine).
The kits weren't cheap - they used a water cooled bearing IHI unit also used on the Calloway Corvette (albeit the V8 used two of them), and the kit (still available) costs about $3K.
A kit using perhaps a less expensive readily available blower unit and including the piping and exhaust to locate it in an MG would be an interesting proposition. Starting with an alloy head engine, say a 3.9, should allow an output somewhere in the high 300 range - not exactly stunning by today's standards, but pretty interesting in an MG, I should think.
With my 2800 lb. car, the turbo 3.2 allows me to blow off Acura NSX, some years of Corvette, etc. Can only stay with those dratted Toyota Supra 320 BHP twin turbos.
Think what the same power would be like in a car weighing 800 lbs. less......we get 13 sec. 1/4 and sub 5 sec 0-60 already (OK- some of that is due to the better accelerative properties of a mid engined car, but you get the idea)
If you think I am kidding about a remote mounted turbo, take a look at the STS system for late model Camaros (no room under those hoods with an LS1 under there).
They run the turbo back where the muffler is (a turbo acts as a muffler - you only need a resonator to make them civilised) and pipe the boosted air back up to the intake - with no throttle lag.
I see no reason at all that this couldn't be done in an MG.
In the case of the Camaro, 7 psi bumps you from 313 RWBHP to 463.....
|Thanks Justin - guess the extra brackets screwed the links up.|
|It looks interesting but I have to question the suitability for the application. While an optimal lag time of .05 seconds does sound quick that sounds like an ideal result and real world could be slower. This demo they did was apparently directed towards general driving, stoplights and maybe dragstrip use and might not be quite so at home on a road course. And there's not a lot of room under an MGB.|
As someone with experience building and driving a turbo V-8 MGB my opinion should carry a little weight I would think, and I believe there are much better options available unless you are just going for the gee-whiz factor. In curves the MG is somewhat sensitive to sudden changes in power, particularly at or near the edge of adhesion. With a smooth and progressive powerplant this characteristic makes them a joy to drive hard, as power induced oversteer is easily modulated to control a drift or powerslide. But any irregularity in the power delivery upsets the balance and can do so quite badly under the wrong conditions. (Which is all to common on public roads.) A turbo by it's very nature will have some lag. Intensive engineering efforts can often minimize the lag but it is still there. Unfortunately for us, nobody with that kind of resources is engineering a perfect turbo system for the MGB. And the lag is the killer, both figuratively and literally. It is the one and only reason that I decided to run a rootes style blower instead. A decision I have never once regretted.
|I've often thought that all that space in back of the MGB could be put to good use. Although you've got a couple of meters of intake pipe, an intercooler would should have a similiar amount of square inches to fill and a similiar lag. You could even flatten the pipe to get more surface area.|
However although your molecule of air is moving pretty fast, I wonder how long the pressure takes to reestablish after opeing the throttle, not 0.05 of a second I'll bet. Would there be pressure surges because of the length?
It's a worthy notion though
|Jim your comments about the B's behaviour at or near the limit are well made. I had never considered that issue in the turbo/supercharger debate that goes on in my mind from time to time. My thoughts have always been on using the "free" energy from the exhaust. However, I think it must be these different power delivery charicteristics that has made super chargers so popular with M-B, Jaguar etc..|
Pete you need to remember that with an itercooler it is only the inlet that is going around the world and back not the exhaust. With the remote turbo charger the exhaust has some distance to travel from engine to turbo as well. I don't know where you would but the remote turbo on a B, but ground clearance issues make putting it in the place of the front box problematic. I guess you would go for the spare battery bo location in a 12v set up.
|Perhaps I should say I am a turbo fan. Of my last 6 saloon cars 4 of them, including the present one, have been turbos, but they were all front wheel drive which changes the situation Jim describes.|
Infact 2 have been turbocharged MG saloon cars. The MG Montego Turbo had a blown through SU carb. The current one, an MG ZT 160+ has blown through fuel injection.
|You would probably mount the turbo in the space formerly occupied by the main silencer. With a turbo, a tip resonator is sufficient.|
This thread was discussed between 07/06/2006 and 10/06/2006
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