Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Performance Melt Down

The performance of my F is so much better when the weather is cold. This evening it was going so fast, making me think it doesnt need any modifications.

However, during the daytime it runs at 120c+ and it feels much much slower.

Does anyone have any tips for keeping the engine as cool as possible?

Anyone used "Water Wetter"?

I think the key is to get cold air, rather than keeping the engine cool. Hence the benefit from an improved induction system.

L Reid

Yup. It's an air density thing.
David Bainbridge


Will an induction kit decrease the average air intake temperature, or increase airflow?


Water Wetter has been discussed a lot in the past.

No clear conclusion was reached with some swearing by it and some (at the time) attempting to blame it for breaking things.

I'd still be interested to try it out as I think that there is something in it.

And as for cold air... the other two posts have it spot on... get a ITG airbox kit thingumy. That'll "cure" 90% of your warm air problems methinks.

Paul Nothard

ps. Induction kit will decrease temperature of the air and improve the flow. It's one of the few mods that is very very worthwhile. Go searching the archive for ITG.
Paul Nothard

Here's a interesting one ?

What would happen if you ran a large duct from your aircon discharge to your air intake !!

Hey presto very cold air !! not sure about the throughput though ? but in theory it would work wouldnt it ??

He he he


Cold air is all when it comes to performance, as it is denser, and therefore contains more oxygen.

Sort out your induction system so that it only draws ambient air (not enginebay air, as the standard system does) and you'll feel the difference. Enclosed filter systems are best: ITG Maxogen, Hurricane, PiperX Viper being excellent examples.

The ultimate is a charge cooler... but to justify it you really need forced induction to take full benefit of this kind of kit... ;o)
Rob Bell

Paul, thanks for the posts, just convinced me even more that i need (!) an ITG. Have you go the 52mm TB?

Stu, thats really the kind of mod im after. Nice and cheap. Potentially very effective, but dont have aircon :(

Perhaps the engine would run cooler if ducting pipes ran from engine bay to the undersides of the car, underneath the other air intakes?

>What would happen if you ran a large duct from your aircon discharge to your air intake !!

Nice theroy, but consider this:
1.8 litre engine @7000rpm (one engine cycle per 2 crankshaft cycles)
=6300 Litres per minute, that is wide open throttle, good airfilter and high revs (worst case!)

Which is a lot of air - how much cold air does the air con give out?

Will Munns

Hmm - unlikely to be able to supply your engine's thirst for air Will, but mixing it with the ambient air intake, it should be enough to drop the intake charge by a degree or two...?
Rob Bell

Rob, possibly, but note the aircon sucks power to keep itself cool AND switches off under heavy acceleration.

I was thinking about this (as you do) and wondering how easy it would be to drop the temp of the air comming into the car (vents). A cheap turbo charger rigged to the exaust to get power, compresses the air into a high pressure vessel in the airflow (this vessel gets hot, but cools in the airflow), the air is let out and cools because of decompression, I wonder how much power this would use, and how heavy it would be, and how viable it would be. Of course it is never going to happen, I have many free brain cycles, and not a lot of free money or time!

Will Munns

Bit of a red herring but, on the aspect of mods...

the 1.8 mx5 has the option of a turbo conversion, sub 2000 pounds.

does anyone reacon this could be added to the 1.8mgf?

Peter- sadly not, there is a problem with heat in the F, there is a turbo conversion, but it weighs in at...

wait for it


6K !!!
Will Munns


Am I missing something? six kilogram does not sound very heavy to me.

Ted Newman

I think he meant Ģ6k Ted.
Paul Nothard

>>Rob, possibly, but note the aircon sucks power to keep itself cool AND switches off under heavy acceleration.<<

LOL, good point Will! Still, a charge cooler operates under similar principles to an airconditioner...

Turbocharged aircon Will? Blimey...!!!

>>the 1.8 mx5 has the option of a turbo conversion, sub 2000 pounds.
does anyone reacon this could be added to the 1.8mgf? <<

Peter, yo could use the turbo charger, but almost nothing else. You'd need a new exhaust manifold, modified inlet manifold and a new ECU. Then you'd need to lower the compression ratio, or the turbo will simply blow the engine apart. It's a lot of work- and the reason why properly engineered conversions cost so much (check out the BBR GTi web site for more info).

A better option would be to wait a couple of years, and pick up a second hand R75 1.8 K-series turbo...
Rob Bell

R75 1.8 K-series turbo

are these actually being made. If they been around for 6 months, there WILL be a damaged one somewhere in the UK.
With its engine just waiting for the car it should have been put in...

Rob, are you saying that if i find a turbo k series it will be not too difficult to fit.
If its straight forward, i will consider placing a request with a nationwide breakers association to source one of the first available : )



75 1.8T has been out since start of june 2002,

That means one can be sourced from rover parts!?

Dont know anything about how easy it would be to fit.
Bet the engine is cheaper that 6k


:-) ted

>Turbocharged aircon Will? Blimey...!!!
You can see it now can't you, sorry officer, it was so hot and i just HAD to get the turbo spinning...
not much use in traffic jams though!
Will Munns

Peter, it's a little too early to find them smashed just yet - they're just too new - as Ian says, they've only just been released onto the market as of June/July 2002.

Ian - yup, should be available from Rover parts (or even through their racing division).

No idea how easy it'd be to fit. I had a look at a picture of the engine bay shown in Autocar. The inlet manifold is (or appears to be) plastic - as per 1.8i. If of alloy, then dimentionally, this is the same - so no space constraints around the rear of the engine :o)

I found it practically impossible to judge the size of the new exhaust manifold that incorporates the turbo charger - I believe this to be the area of the greatest difficulty.

I'm sure that there'll be a turbo 75 in your local dealership in due course - takes some pictures, and a tape measure!

Rob Bell

Rob, do you know of any company that would undertake the engine swap.
(Its not the usual merrits of chesham service request!)


The first name that springs to mind is Mike Satur's, Ian. He's got such a depth of experience with F's that if something doesn't quite fit, he'll be able to do something about it. Plus, he's talked about engine transplants in the past...

Plus, you may start a new market for turbo transplant cars, so there may be advantages for him to take on the work.

There are other names that come to mind, but I reckon he may be your best bet
Rob Bell

I will have to find out the part number and availability of the 1.8T.
Then assuming its not stupid money e.g. 5,000 I will consider contacting an engine converter.

There does seem to be a stark variation in Rover parts prices. So this may take some time to get a realistic cost.

As you suggest, this is something Mike Satur might consider.

Many thanks


Before we all get too excited about transplanting the new 1.8 turbo out of the 75 into the F, let us not forget that it produces less power than the VVC and has been designed to delivery stately progress for the 75 and not sporting performance in the F! It does delivery the peak torque lower than the VVC but again this aids stately progress, not rapid progress.


Patrick Beet


You make a valid point.
But, am I right in thinking that with the turbo in place the opportunity for performance improvements will be far greater?

If a secondhand 1.8T can be sourced it need not cost anymore than a standard 1.8 unit. Since the majority of breakers will be unaware of its potential desirability to F owners. Perhaps it will carry a 20 percent premium, but it is still worth buying.

I have looked into the performance modifications available for my F.
52mm TB, Maxogen and exhaust fully fitted is approx 1000 pounds.
Mike's engine stage 1 2 3 are not cheap.
Perhaps this method will work out cheaper.

My last car was turbo engined, the power delivery was just unbelievable, so much fun, so much power...

A friend of mine owns a 2.0 Turbo engined F and the conversion costs were massive.
I want to replicate the performance of his car, but at lower cost.


Has Anyone heard anything from the guy that swapped a 1.8mpi for a 2.0 turbo (from Rover 600 series)?? I remember 1 thread and thatīs it, vanished. Never saw any pictures or other posts. Although I am curious as h*ll, I beginning to doubt whether it really hapened!
AFAK the swap was pretty straightforward, although the higher weight posed some problems, it was completed within a month wasnīt it?

Rob, didnīt you get in touch with him for a MG World report?

Wiperless (still) David


David, no he didn't. I haven't seen any pix either. A friend of the owner of this car has posted on the general board... can't remember who or what it was about - D'oh!

Patrick - I've got to disagree with you about your assertions that the 1.8T will be a tardy motor. It won't be - and certainly not when shoe-horned into an MGF or TF for that matter.

Two factors:
1. weight (an F weighs a little under 1/2 of a 75)
2. torque - the torque curve from the turbo is prostigious.

Infact, when Autocar road tested the 75 1.8T, they felt that Rover had a winner on their hands - and through the gears, they felt that it was faster than even the 2.5 V6! The reason? Torque.

None-other than Gordon Murray (he of Maclaren and F1-designer fame) has clearly stated that acceleration is more a question of torque over mass. Power has more bearing over ultimate top speed - and let's face it, here in the UK top speed is pretty academic anyway.

So we have a turbo that puts down 215 Nm of torque. The VVC and the 160 both have a relatively miserly 174 Nm. So what we have here is close to 25% increase of torque.

This will be a hugely impressive engine in an F.
Rob Bell


> 1.8 litre engine @7000rpm (one engine cycle per 2 crankshaft cycles)
> =6300 Litres per minute, that is wide open throttle, good airfilter and high revs (worst case!)

Consider a standard engine (120bhp at 7000) and a tuned engine (200bhp at 7000). The tuned engine would require more air.

Maybe the formula holds when the volumetric efficiency is 1.0 ?

A different approach might be:

x * engine-bhp where x is the volume of air in litres/second required to maintain 1 bhp ?

Anyone know what value x is ?

First time I have thought about this ..


BTW, I have looked into inlet temps before and have been told to expect a 3% increase in engine power per 10 degrees C drop in air temperature. It's a lot ..

Russell Morgan

Russ, I wasn't going to pick on Will for this! LOL
You're right though - more powerful engines have higher volumetric efficiency, and therefore a healthier appetite for air.

Somehow, I doubt that the volumetric efficiency curve is linear - clever design of the inlet tract leads to a ram-air effect, sucking in air at high rpm to improve volumetric efficiency...

Ah, the joys of trying to understand automotive engineering! ;o)
Rob Bell

Errm, yes there are some huge simplistic assumptions in the equasion. They are all to do with pressures in the system.
1) That the inlet manifold is at atmospheric pressure (which is more true the wider the throttle)
2) That the tempeture of the air is the same inside the cylinder as in the inlet manifold (at 7000 rpm this is probebly true)
3) That no exaust gasses are still in the system, this is almost certainly untrue, if the exaust stroke has open valves all the way to the top of the stroke then there is still 10% of exaust in the cylinder (compression 10:1). This assumes that the pressure in the exaust is atmospheric, and no higher
4) That the pressure in the cylinder at BDC when the inlet valves close is the same as the pressure in the inlet manifold- very unlightly at 7000 rpm

so for tuning:
1) a wider throttle body and good performance airfilter will limit the diffrence
3) a performace exaust will alow a free'er flow of gasses away from the engine, as will fitting larger valves
4) gas flowing the head and enlarging the valves will help the pressures equalize quicker, but you will still not get a perfect match.

Will Munns

>expect a 3% increase in engine power per 10 degrees C drop in air temperature. It's a lot ..

10 degress is a lot, an awfull lot! To get 10% incresse you would have to cool the air down to a tempture where it would start to conflict with the atomization of the petrol, and this would knacker your performance!
Will Munns

No bad feelings will :-) I have a genuine interest in this subject as I'm soon to modify my car (non-MGF) to use an air box and had no idea that the quantity of air required would be on this scale!

Russell Morgan

None taken! I try to take all posting here in a favorable light, I didn't think there was anything I ought to have bad feelings about!
Will Munns

> 10 degress is a lot, an awfull lot!

Not if you think of it round the other way - You are in a queue of traffic waiting at the lights for 5 minutes and the engine bay temp probably rises to over 50 degrees above ambient = maybe 15% loss of power when you leave the lights until the engine bay temp cools down.

If ambient is 20degC and at 60mph the engine bay temp is 30degC then there is 3% power to be had by ducting 20degC air into the engine..
Russell Morgan

There is also the danger that the ECU retards the engine and decreases the fuelling at high air temps - even less power. This happened with me on my aftermarket ECU.
Russell Morgan

Ah, I was thinking you were talking about cooling the air to the engine, rather than just getting cooler air IYSWIM.
Yes there is a large opertunity for the engine bay to heat up at lights, but how long at open throttle does it take to empty the engine bay of all air?
Will Munns

>danger that the ECU retards the engine and decreases the fuelling at high air temps
on an F? I didn't think that it had a air temp sensor on the inlet manifold
Will Munns

> how long at open throttle does it take to empty the engine bay of all air?

I don't know on an F but I think it will surprise you how long it takes for the air temp to drop.

If you have one of those digital indoor outdoor thermometers, strap the air temp sensor on the side of the filter and go for a drive..

> I didn't think that it had a air temp sensor on the inlet manifold

I'm pretty sure it does.

Russell Morgan

Russ, if that midget of yours gets any faster, it'll take off!!!

(That's let the cat out of the bag - Russ, Will will probably want to have a chat with you regarding K-series conversions in Midgets).

So you are going for MTBs? Cool. Which ones? An airbox is a must. As an aside, I have to say that I am not terribly keen on the place that Tim leaves his filter assembly (rammed up against the bulkhead).

Do you have the M3D ECU fitted?

Been thinking along similar lines for my F. All pipe dreams at the moment: just trying to learn my way around the area of K-series tuning. I figure that this is a more prudent route than diving straight in ignorantly! ;o)
Rob Bell

>if that Midget of yours gets any faster, it'll take off!!!
Oh oh oh, can I have a drive?
Will Munns

Hi Rob,

As it's a bit off topic I'll put your questions on the K Series Midget board and answer them tomorrow ( as long as I can find a bit of spare time :-)


Russell Morgan

Couple of points.

1.8T is very compact but as with any turbo there is a massive heat issue to deal with and the F/TF engine bay is going to struggle with this. This is why supercharging is chosen for such engine configuration as here you only have the heat generated by compression of the air to deal with. BTW don't expect a ZR or ZS to be equipped with the 1.8T motor, at least not in the next 12 months.

Adding a heat exchanger for the inlet air may reduce the intake air temp but then you see a significant pressure drop either side of the exchanger whatever the type. To exchange heat from the air to another medium requires that there is contact between it and the surface of the device through which your transferring the heat. This creates drag and so has a similar effect to a throttle. To have a heat exchanger with good flow characteristics means heat will not be exchanged!

This is the scenario that has faced those creating forced induction engines from the start. On the one hand there is the issue of increased intake air temps losing power, on the other is the reduced flow efficiency from inserting a cooling matrix. The balance is usually at about 6 to 7 psi of boost. below this (which included naturally aspirated engines) and you actually see a reduction in power, but above this the cooling gains are greater than the flow losses so you see more power.

On the F many may remember my mods about 2 years ago, to the original air intake system. This was taking out the resonator and connection the 'cold' air pick up direct to the air filter box, and routing this to near the left side intake. The results were in an average 12 degrees cooler intake temp as measured in the airflow at the throttle body and an extra 9 ft lbs in peak torque. Power was also increased by 6, but this included a K&N element in place of the original paper.

The T16 engine is easy to fit to a PG1 gearbox and so is theoretically easy to drop into an F subframe. However it is much longer than a K4 and so the pulleys and cam belt drive will be sitting where the inner wheelarch and upper part of the suspension sits!!! I have looked into this and some major work would be needed to body and chassis.

All K series run with an air temp sensor, not in the ideal position though as it is in the no 4 inlet tract about 20mm from the head face.

1.8T engines are much more than just an engine so the assessment of 5000 pounds is likely to be a realistic minimum price for new parts. The F cooling system though will be unsuitable as it will have to have additional cooling capacity so there is the potential for a few hundred more pounds.

This before any consideration is given to raising power and torque. If you do then there is a question mark over the gearbox capacity which is 215Nm, exactly that which the engine gives in standard form. It should be able to take 10% extra on a long term basis if in good condition to start with, but a gearbox with more than 40k miles may well see the turbo torque rip it to pieces in a very short time. This from experience with PG1 and turbo motors since the 1980's!
A solution is present in the form of an uprated gearbox which is rated to 240Nm. However this is extra cost and you have to find the right ratios. Most are close ratio low geared for high revving K series sport applications rather than an engine which has the opposite attributes.

All this is simply to illustrate that the change of just an engine would create a failure in terms of the overall package. To make this a success needs to keep the overall balance with all sorts of aspects within the vehicles spec and of course I haven't touched on brakes, etc, etc.

Roger Parker

Cool thanks for the info Rog
Will Munns

Thanks Rog - learnt alot there; expecially about the two torque handling versions of the PG1 gearbox :o)
Rob Bell


Maybe I'm missing something here, but Ian said:

>A friend of mine owns a 2.0 Turbo engined F and the conversion costs were massive.
I want to replicate the performance of his car, but at lower cost.<

Perhaps this car is the conversion which was mentioned on this bbs a few months ago? And perhaps the new owner would be willing to do an article on it for MG world?

I can imagine that this car is fast. Not sure if any tweaking of the 1.8 would get to this level of performance? Would be interesting to get dyno / speed stats and some pics!

Cold air is the first stage in a lot of tweaking Ian, though if you're friend has the motor that was mentioned in here a few months ago, there will be a lot of cost in getting that performance!

Take your mate and his car down to Mike S, let him have a look at the car, and get an idea for the sort of performance you're after. He'll be able to let you know if it's possible, and for how much.

L Reid

Yes thats right Leigh.

I too was interested in the 2.0 turbo conversion. A conversion on that scale does not go unnoticed, so asked around.

I was pointed in the direction of the garage in the Midlands. The car is special, but in its current state, not worthy of major attention.
The owner has spent thousands on the conversion.

Apparently tuned to over 230bhp, with an improved suspension and brake set up.

However, "teething problems" e.g. engine blowing itself to pieces - so hot.... and more!

A major rethink is required before further work can be done.

I am considering buying the car, stripping it out and fitting the 1.8 turbo conversion. Hence my most recent threads, (many thanks for the input).

In its current state, such a conversion would still be economically viable.

It would be nice to return it to something of its former glory :)


I'm sorry to hear the car's had problems. We all thought it was a interesting project, and would have liked to have got some positive feedback.

IIRC, the adequate engine cooling requirements were mentioned at the time of the thread. It's sensitive enough with the standard 1.8 lump in it.

As I remember, an alternative engine was also mentioned (Honda possibly), with more power but of a similar dimension to aid the cooling issue. I think they ended up with the 2.0 turbo as it was available, rather than cause it was the most suitable.

Someone else was fitting a Nitrous Oxide system to their 'F', but I can't recall reading if they managed to get it working or not.

I also suggest getting the last couple of issues of Car Mechanic. Mike Sauter has been doing some work on an 'F' for the mag, including some porting of the head, and fitting uprated suspension etc. Combined with the added benefits of improved induction with the porting, you should start to see gains in the performance, hopefully without the engine blowing up (too quickly anyway).

SF's had the porting done, and was happy with the results IIRC.

There are others who are more quailfied to comment on this stuff, I'm just remembering stuff I heard about, not actually done any of this to my car! Might be worth starting a new thread if there's no responses to this one anymore.

Good luck,

L Reid

Sorry to hear that the engine in your friend's car has wrecked itself. From accounts that I've heard, heat is the reason why the 1.8T will not be a production option for the TF.

Whether this means that heat represents an insoluble problem or whether it simply means that MGR reckon that there are easier and cheaper ways of getting the same power without having to resolve the heat issue is a matter for conjecture.

I reckon it is possible, but meticulous attention to detail (especially heat shielding and plenty of insulating exhaust wrap) is essential.

Ian, if you go down this route then MGW would certainly like to hear about it (and that applies to the T16 turbo conversion that your friend owns). Let me know.
Rob Bell

This thread was discussed between 20/08/2002 and 27/08/2002

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.