Modified MG Maestro Turbo

[Mike Brock]

If you were thinking of a T series there is a forged engine coming up for sale on rovertech, if you look in the for sale section. Cableguy is the seller, he is a decent chap and builds engines so you can trust it will be well put together. Arias pistons on T series rods.

Couldn't find the information on rovertech? if you could send us a direct link regarding the forged engine for sale it would be much appreciated. I have to say though its looking very likely that I'll be using the O Series engine.

Mike, I've done both engines in the Gooon and I wouldn't use either now

Both have there pit falls at over 250bhp and there are much better alternatives available.

Audi TT engine is the simplest swap as Reyland sell an adaptor to fit the PG1 gearbox

Or

T4 Volvo engine and box which is the route I plan to use once our T16 is done for, or if someone buys it for 2k

i presume quite a lot of usable Hp can be had from the T4 Volvo engine? why can't you take the T16 further? I feel you didn't explore the O Series engines true potential when you had it fitted into the Gooon.

[Guest]

i presume quite a lot of usable Hp can be had from the T4 Volvo engine? why can't you take the T16 further? I feel you didn't explore the O Series engines true potential when you had it fitted into the Gooon.

Not sure why you think we didn't explore the potential, despite asking numerous times for proven 300+ O series engines no one ever came forward with any proof or specs for us to compare and how many 270bhp O series are there?

Summary of change from O to T

O has a massive torque spike due to its design, we had nearly a 160ft/lb jump in torque within 500rpm. It was not progressive enough or smooth enough to drive effectively out of slow speed corners.

In the end with a T34/55 turbo 20psi of boost we made 270bhp with 350ft/lbs of torque. If we had pushed the O to 350bhp+ would have had an even bigger torque problem as well as turbo surge which had began to show with the T34/55

Changing to injection would have helped, but then you may as well look at an alternative crossflow designed engine keeping the inlet away from the hot exhaust, hence changing to a T16

Summary of T16

It runs seriously hot, its fragile, its has more potential leaks than an A series, its big. In stock form its pistons are made by Cadburys, its cams have no lift or duration, its valves are tiny. But its much much better to drive, much more progressive, more useable power accross the rev range than the O

I read up on the potential of the T16 and was taken in by the claims made on Rovertech etc and it doesn't make the power claimed for the boost levels stated, its cost us a lot more than expected to get to where we are now

New cams, valves, pistons, rods, extensive head work etc in hindsight I would not use a T16 again as when it blows it'll cost another £5k+ to get back to where we are now

Onto the alternatives

Volvo T4

The Volvo engine can do 400bhp on stock internals although new rods are recommended at this level, all other items are stock Volvo items

Use the 2.0 turbo block, pistons and crank, with 2.0 N/A head and cams. 850 T5R clutch and flywheel and modified T5 exhaust manifold, stock gearbox with Gripper diff and job done

Its nearly 50kg lighter than the T16/PG1 setup, has a jack shaft for equal length drive shafts, its smaller and cheaper to build/rebuild as 99% of the engine is standard Volvo items

Most importantly its been proven to make this level of power

Audi Engine

The 1.8 turbo has a few variations but the 225bhp engine has been proven to be reliable at 350bhp, can bolt straight onto the PG1 with the Reyland adaptor plate and is very light.

Above 350bhp then the crank and rods need attention but for fwd and the road 350bhp is enough

[Mike Brock]

hi ratty - i didn't know you were experiencing turbo surge problems - that will put a damper on things all considered! I presume changing the turbo for one that matches the pumping efficiency of the engine will cure this surging? I think that explains why you didn't go further though i have to say i was a little disappointed It doesn't help matters either if the engine torque curve is so narrow it justs wheel spins out of the slow speed corners as you describe! It would of been nice to see the 300Hp barrier broken with the O Series engine - as like you - i have been searching for that elusive proof that these engines can really get up and go.

I have a suitable O Series turbo engine that had 2k spent on it. AVA in Glasgow built it. It has JE Forged pistons that lower the cr 7:1 - balanced bottom end inc pulleys - wire rung block - polished and ported head - uprated Piper camshaft with vernier cam pulley - T34 turbo with modified down pipe and ss 3" exhaust system that cost a grand to build. I'll be running twin su's with the proper throttle linkage. Huge front mount intercooler that i bought of victor (mental maestro) - i also have a 3 core chargecooler that i want to add to the system. Hoping for 270Hp at the least though 300 will be the main goal.

[Guest]

Sounds a simular spec to our O series, we used T34/48 and T34/55 and both produced surging. I recon 24/25psi on a T34 will do 300BHP but will it be driveable or pleasureable to drive, I doubt it.

Maybe a GT28 spec turbo would be better suited, alas we moved on before trying one, or custom high lift cam

One word of warning, watch out for heat around the bulkhead. I melted a passengers trainers on track with the T34/55 and 3" exhaust

[countrydude]

Sounds interesting, what is needed to get to around 300bhp? Bigger turbo, injectors and remap?

Seems the adapter plate needs a custom flywheel coming in at over £500 so not such a cheap option.

Audi Engine

The 1.8 turbo has a few variations but the 225bhp engine has been proven to be reliable at 350bhp, can bolt straight onto the PG1 with the Reyland adaptor plate and is very light.

Above 350bhp then the crank and rods need attention but for fwd and the road 350bhp is enough

[Guest]

300bhp is never cheap, but once conversion parts are bought then any engine replacement is very cheap

The 1.8T engine can do nearly 300bhp on just a remap if starting with one of the higher powered engines ie Cupra R

[countrydude]

300bhp on just a remap is amazing. I'll look into this if and when I need another engine for the maestro as it looks like a good powerplant. There are so many varients of the engine to get seriously lost is my concern. What is the standard power output of the cupra r?

[Mike Brock]

Sounds a simular spec to our O series, we used T34/48 and T34/55 and both produced surging. I recon 24/25psi on a T34 will do 300BHP but will it be driveable or pleasureable to drive, I doubt it.

Maybe a GT28 spec turbo would be better suited, alas we moved on before trying one, or custom high lift cam

One word of warning, watch out for heat around the bulkhead. I melted a passengers trainers on track with the T34/55 and 3" exhaust

Remember ratty we're talking about a compound charged maestro here so bottom end tractability does improve. The transition of on/off turbo boost is not so apparent as the supercharger is already blowing 8lb of boost into the engine before big over sized turbo spools up. Yes you will still experience the boost spike as you describe but the drivability before that is awesome. The supercharger I'm using this time around is an Eaton m 45 from a bmw mini copper.

[Guest]

Spooling was never an issue we were on boost by 2250rpm and at full boost before 3000rpm

The graph below shows 18psi on the T34/48 with the torque spike very apparent between 2500 and 3000 rpm, our main issue with surge was at part throttle in the mid range and was fixed by going WOT which is easy on track

[Mike Brock]

Have you got the 270Hp / 350lbft torque rolling road read out that you achieved with your O Series?? That would be interesting to have as well on this thread so we can compare notes with later on. I have spoken with Nigel Hunt Turbo Dynamics regarding a suitable turbo application - he recommended the GT4088 - they have very low rpm outputs and as such use quite different size turbo/engine size calculations. Garrett recommend this turbo for engines between 2 and 6 litres and with outputs from 450-700BHP. Normally it would produce pretty poor results on a 2Litre engine, but with my supercharger providing the low end spool, this could give me exceptional results! Do a search on youtube - GT4088 - to get an idea how big it is lol.

[countrydude]

depends how far you want to go. I'd say with aftermarket management and converting to efi you should break the 300 bhp barrier easily! Especailly with a t4

[Mike Brock]

yes going for an injection set up would be the ultimate goal. The problems with that is where do you begin sourcing parts from - and the cost. You might as well go for a T16 set up considering everything you would need imo. Besides - i would try first the Dellorto DHLA 45M carburettors - which can hold up to 30-PSI boost pressure - these are from a Lotus Esprit Turbo.

[E_T_V]

Aftermarket ECU and EFI manifold (or something custom). All said the biggest weakness of the standard turbo was the SU carb. If they had stuck with fuel injection it would have been so much nicer to drive and own!

[countrydude]

yeah the efi manifold has to be useable, with better 550 injectors you get to 300bhp in no time!

[Guest]

Been away for a few days, Mike I never uploaded the final graphs and lost the paper ones in a move a few years ago. I tried to get new copies but slarks no longer had them saved.

IMO as soon as you start to consider injection then you may as well change engines