TF subframes into an F

[WingNut]

Hi,
I've done a quick forum search but haven't found the answer so can anyone tell me will the mg tf sub-frames fit into an mgf? with or without modifications?

[nigelandjo]

They have different part numbers on the Rimmers website, so I would guess that they are different due to the different suspension set up.

[WingNut]

Thanks for the reply, I'm sure the sub-frames are different but did a cash strapped MG Rover just modify the outer panels on the tf and leave the sub structure the same as the mgf? If the sub-frame mountings are the same maybe it will be possible to change them.

[ste_no1]

I believe that all fixings to car are the same but you have to drill a hole in the top inner wings for the front struts to clear. Then also clear a small section for rear struts aswell

[Rob Bell]

Fitting TF subframes into an MGF has been done many times. I may well do this on Project Shed in time. It is *nearly* a straight swap, other than the need to make a hole above the front suspension towers as ste mentions... (see illustration below)

[WingNut]

Thanks for that info, this looks like a good mod so I will get everything prepped and do the switch in the autumn. Any tips on other jobs that it's worth doing while the frames are out?

[Rob Bell]

Yes - check and if necessary replace the hydraulic lines (brake and clutch), as it is easier to do with the subframes out than in.

Also do a complete engine "C" service, and consider changing the clutch too - again, much easier if everything is out of the car.

And naturally check for any corrosion. There shouldn't be much evident, but an opportunity to kill any oxide early

[The old one]

I changed mine a couple of years ago and it is a virtual straight swap. To make it easier, make up a template so you so you know exactly where to cut the holes in the inner wings. I went to the breakers yard and purchaseed complete Tf front and rear subframes stripped them down and had them shot blasted. From memory the rear hub fixings are slightly different, I also purchased the soft ride suspension from Rimmers, but as Rob said, while the engine is out change the clutch and the shaped steel heater pipes, and anything else that looks worn.

[Swampy]

My question is this: which is the better subframe for competition?
I have acquired another MGF VVC, which will eventually become my hillclimb/sprints car. The hydragas suspension has been removed (supelex installed) and though I do have a full set of spheres at home I'm not really keen on going back to it. I've also cracked the chassis on my green MGF with the RV8 spring setup, so need to be wary. I have a set of TF subframes behind the house, so no real expense involved.

Articles I've read suggest the TF suspension setup is better than the F (more sharper, agile). What are the "MGF Cup" cars running, F or TF subframes?

[Rob Bell]

Really good question. I don't know, but I have TF subframes that I plan to fit to Project Shed. I can always reverse the mod if it is a retrograde step. But in my mind (so that's not hugely reliable then! ), TF has better geometry control over the rear wheels, and being "archaic" springs rather than Hydragas, every man and his dog knows how to set up, fabricate and adjust it. It opens a much wider marketplace of coilovers.

But what I like about Hydragas is (1) compact size, (2) relatively low weight and (3) relatively stiff roll resistance for a particularly compliant primary ride - which means good tyre to road contact even when the road surface gets rough.

It is a toughie - but there's only one way to find out: swap over and compare times before and after!

[Swampy]

Thanks Rob, with one cracked chassis after a spring conversion, I’ll try the TF subframe. I’ll always have the F one as spare parts.

[Rob Bell]

That's my plan too. If it doesn't work out, I can reverse the modification pretty easily!

[talkingcars]

Hi,
I've done a quick forum search but haven't found the answer so can anyone tell me will the mg tf sub-frames fit into an mgf? with or without modifications?

Having just completed the change from F to TF - yes, a straight swap.

[Rob Bell]

Did you take pictures James?

[talkingcars]

Did you take pictures James?

Of anything in particular?

[Rob Bell]

I would ideally like to get the location/ dimensions of the holes that need to be made in the underbonnet panels to clear the suspension turrets James. I am sure I can work it out, but obviously easier if someone has already done the leg work!

How are you finding the conversion?

[talkingcars]

Um, I hadn't read the bit in the manual that said you need to drill a hole to let in the suspension until after I had the subframe in place and as a result it isn't perfect. I will try and get you some info over the weekend.

As for the conversion - I love it, even running the worst possible tyres on the front (the non directional Pirelli P6000) and not having had the tracking done it is so much better than the tired hydrogas.

As I was aware that the TF has a much more sports car ride and we generally use the car as a long distance tourer (GT-grand tourer) I wanted to retain some of the compliance of the F. I used the rubber bushed MGF subframe mounts (they are also less prone to failure due to rust). I had some polybushes made up in 70 sure which is close to regular rubber and got them in green to match the car. Most of the moving parts were changed for new ones, after all the project grew from needing to replace a holed wishbone.

The final piece of the jigsaw was the MY2005 springs and shocks, brand new from Rimmers who price matched an eBay seller who couldn't actually supply. I have no real experience of the original TF ride except for moving the donor car around the car park at work so can't compare but the new ones work really well. Incidentally, even with the price matching they were more than the cost of the subframe donor car, even before all the parts I have, and am still selling off.

I also used the TF steering rack which mas a much better turning circuit. I have done the engine bay braces but not the front subframe bases or underdash brace yet.

Even Mrs TC, as a passenger, noticed the improved ride within a few yards.

[Rob Bell]

With the MY2005 springs and dampers, are you using the thicker ARBs? Or the slightly softer originals?

Glad you're pleased with the results The buys at Longbridge intentionally made the TF suspension such that it could be retro-fitted to the MGF as they knew that Hydragas supply was very finite once production stopped.

[talkingcars]

IIRC I used the ARB from the F.
TBH I didn't know there were thicker ones available.

[Rob Bell]

The F uses the thinnest of all the ARBs available. They're 1-2mm thicker on the TF and the comfort pack on the later cars are thicker again.

I don't see a particular need to use the thicker ARBs if the car drives the way you want it to