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MG MGB GT V8 Factory Originals Technical - Turbo?

Hi all.
I am busy getting all the parts together to turbo my v8. I have been getting lots of good advice from other websites but little specific to MGBs. I realise that I am going to have serious space problems under the bonnet/hood. Does anyone have any info/pictures of turbo installations on a v8 in an mgb? The car will only occassionally be used on the road, as it is destined for the local sprint track in order to embarrass a few of the local skyline/subaru boys. I have no problems removing the heater box for space, or even relocating the rad into the back to make way for intercoolers.
Thanks
Nick.
Nick Bentley

Heard tell of people swapping the exhaust manifolds upside down and putting the turbo where the aircon compressor normeally goes.
You should have plenty of room for the intercooler if you cut the front tray out.
Might be fun to have a sleeper.
Peter

Nick,
I had a turbo in mine for a few years before going to the roots style blower, and I can't say I'd recommend it for one specific reason: The MGB's forte is running through the corners. A turbo has a knack for giving you a big boost in power all at once and this makes cornering a whole lot trickier than it is with a smooth buildup of power. If you intend to do any cornering at all I'd suggest you consider a blower instead. The blown V8-MGB is a real pleasure to drive whereas the turbo V8-MGB had me pointing the wrong direction way too often. Just the voice of experience, take it for what you will.

Jim
http://www.mgbconversions.com/photoalbum/variousv8s/JimBlackwood.htm
Jim Blackwood

Wow Jim what a car!
I can see that I will be referring back to your pics again and again over the next few months. That front end..... Is there any way that the inner wings could be cut away and replaced with a brace bar like on a flip front conversion on a mini? That would certainly solve a few space related problems I have at the moment.
I understand what you say about turbo power characteristics, ie. lag and a sudden hit of power. I will be minimising this by using a pair of small (Garret T3) turbos blowing through a couple of pressuised carbs from an MG Maestro turbo bolted onto a standard rover twin SU manifold. The small size of the turbos should reduce the amount of lag and make the car a lot more driveable. If you have any pics of your original turbo setup (what parts did you use?) I would be interested in seeing them.
Thanks for your input!
Nick.
Nick Bentley

I wish you the best of luck Nick, but I could hardly overemphasize the differences in the character of the machine. Turbos are fine if you're going straight but if you're already hitting the corner hot and at the limits of adhesion it doesn't take much of a nudge to put you into the weeds, whereas with the blower the application of power is smooth and controlled and you can take full advantage of the power.

The front end of the car must be adequately braced if the fenders or inner fenders are disconnected from the body shell. Yes it can be done, but it takes careful planning to do it right and not lose stiffness or encourage stress cracking. Note the heavy stainless braces that tie the inner fender and fender stub together, this also prevents fatigue of the inner fender. Removal of the inner fender as well would then require the design of tubular bracing tying the forward frame rails to the bulkhead in a triangulated manner to restore stiffness, and reinforcement of the frame rails themselves would be advisable as the wall is thin and they were never intended to carry the full weight of the front of the car. The tie-in points would need to spread the load over a large area on at least two and preferrably three planes. It'd be quite a lot of work.

My turbo was retro-tech, consisting of an original Olds Jetfire turbo/intake combo fed with a custom hand built 8-4-1 header and sucking through a specially calibrated 2" SU. By modern standards it was low powered, maxing out at 7 lbs, but response was good. It was still enough to have me pointed the wrong way on the freeway a couple of times with bent sheetmetal. Bear in mind, I'd already driven the car with a V-8 in it for a dozen years by then, most of it with a built up Buick 215 which had more horsepower than the turbo motor, and never had those problems either before or after the turbo. I still have the old bits by the way.

Jim

Jim Blackwood

Hi Jim
Thanks for your advice about the inner wings. I have previuosly cut the innners out of a mini and also a Ford 100e (tiny little british ford 1950's sedan) with no ill effects. The ford needed a spaceframe triangulated assembly fitting in its place in order to locate the strut tops. It seemed to work ok but the monocoque chassis legs were really short. On the MG they are a lot longer, therefore more leverage being exerted on them. Coupled with an increase in power and associated stresses, I don't fancy having the car fold up around me at speed! I'll forget that idea.

With regard to the turbo, I understand what you mean about the character of a suck thru turbo installation.
The setup I mentioned has been carried out a few times in the UK already, and due to the small turbos involved it spins up quite quickly due to the relatively small amount of inertia compared to a T-04 for example.

Having said that, the car is being built primarily for the quarter mile, with only a small amount of time being spent on the road, so lag won't be too much of a problem.

I used to own a Renault 5 GT Turbo (did you get them in the US?) and lost that in tight bends in the wet more than once... 150hp in a front wheel drive car that weighed little more than an Austin Mini!

By the way, did all the jetfire turbo kit fit under a stock hood?
Thanks
Nick
Nick Bentley

Just a quick paradigm alteration, you really don't have to put the turbos directly after the engine. There have been a few people who move the turbo back to the rear for space reasons. You have to adjust the hot side ratio due to less pressure in the exhaust, but looks like a good compromise. If I can find any of the sites in the next week or so, I will post them.

Good Luck!

Galen
G.P. Copes

here ya go
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=72205&item=7910856479&rd=1
Jake

You may be interested in the fact that someone in Bournemouth has a twin garret turbo set up for a Rover V8 for sale for £350.
Advert can be found on www.adtrader.co.uk
Good luck with your project
Pete
P A Hawkins

If space is an issue, you could also route the exhaust manifolds forward and put the turbos in front of the engine. Jim has a point - to a point - If you are going to autocross the car, a blower gives smooth linear power. However, if you are not building an autocross car, a turboed fuel injected engine would be sweet. Essentials include good boost control, ignition timing control and good fuelling throughout the rev range, big free flowing exhaust, adequate intercooling, proper manifold design - see a nice diy manifold example at sdsefi.com the link is:

http://www.sdsefi.com/techheader.htm

Also buy the book by Corky Bell , "Maximum Boost" and he will take you through ALL of the essential details.

If you are using an GM engine, there are several sites like TunerCat and a few other forums where folks have reprogrammed GM ECUs by burning new eeproms. This is the cheap time intensive method, or you could spring for a Haltech E6K or a similar standalone ECU for fuel and ignition control.

Turboed Carbs are old school, but it can be done. You will need to enclose the carb in a pressurized box and provide variable fuel pressure to the carb as a function of boost so the fuel doesn't start flowing backwards (ie 8lbs oif boost and 4 lbs of fuel pressure = no fuel= very lean = very hot = detonation = Kabooom). YOu will also need to pull timing while on boost so as not to detonate. MSD sells a box for this purpose.

Sizing turbos is a compromise, too big too laggy but BIG power when it does come on the pipe - abrubtly. Small turbos come on early, not as hard but run out of steam on top and will start to increase the intake temperature more than a larger turbo.

Tolulene is bad for your testicles but good for turbo fuel. Mix with gas to gain octane and prevent engine explosion.

Read Maximum Boost cover to cover three or four times and then you will have the big picture. A worthwhile investment.

Good luck,

Brian C.

72 BGT in V6 conversion mode

90 Miata 1.6 w/ T3 Super 60 .48 AR, Haltech E6K, 440cc RX-7 injectors, 2 WRX IC cores welded side by side with custom endtanks, Weld-El manifold, JC Whitney 3" mandrel bends cobbled together to yield an exhaust system; ACT clutch; VSLD and mechanical empathy holding it together. 220 RWHP.

2000 Audi A8 bone stock (for now)
Brian Corrigan

This thread was discussed between 14/07/2004 and 28/07/2004

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