Standard TF Suspension Settings

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willyphixitt
Posts: 527
Joined: Sun Oct 14, 2007 7:15 pm
MGF Register Region: Elsewhere
Model of Car: 2006(reg) TF135
Location: Jersey

Re: Standard TF Suspension Settings

Post by willyphixitt » Sat Jul 11, 2015 4:22 pm

Hi folks,

I need some expert advice on my TF height settings. I have a 2005 TF135 which has only done around 16k miles. My problem is there are several speed bumps which I am scraping when I go over them. They are too sharp a rise and too narrow to avoid scraping the lip underneath the front bumper before the front wheels touch the speed hump. Crossing diagonally makes no difference. There is one in St. Helier harbour where you can't attempt to cross diagonally anyway because of lane width restrictions.

So, I decided to look up the normal ride height specs. The bible says 358mm +/- 10mm. My ride height is 342mm at the front and 343mm at the rear. And I don't think the previous owner has lowered the suspension.

My question is - how do I increase the ride height? I am as much as 25mm under spec. if you take the maximum tolerance and 6mm at the minimum spec.. Would you suspect worn bushes where the coil-overs are mounted to the body? Do I add another spacer washer - RNS000050 (2.5mm thick) and change the bushes to these polybushes - RNF100090LPOLY? These are the part numbers listed in Rimmer Bros. I would like to get at least a 6mm increase in ride height and hopefully that would be sufficient to clear these damned speed humps.

All comments gratefully received.

willyphixitt

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Hot-modsPhil
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Joined: Sun Aug 16, 2015 10:12 pm
MGF Register Region: Somerset & Dorset

Re: Standard TF Suspension Settings

Post by Hot-modsPhil » Sun Aug 16, 2015 11:12 pm

Hi,
I know a bit about this as I have been working with a Shocker manufacturer (Protech) on some aftermarket TF shocks for the last year.
The figures you mention tally with standard suspension. I've never seen the 358+/- 10 figure anywhere else, but a ride height of around 345 is normal with standard suspension and indeed within a few mm of my TF 160, which has standard suspension. Maybe they just settle after a while.
The way the sports suspension differs on the TF is that the lower spring mount is welded to the shock further down the casing allowing the bottom mount to be effectively closer to the top mount before the spring equalises the weight, and they use slightly stiffer spring and shock valving to compensate for the reduced piston movement which results.
You of course want to increase the ride height which is opposite to this, so there are a couple of ways of doing it.
1. Get Shocks that you can adjust the position of the lower spring mount.
2. Get stiffer springs which equalise the weight earlier in the travel but ride quality will suffer.
Unfortunately adjusting things on the top mount won't make any difference apart from giving problems with the top mounting rubbers.
If you need any other info, send me an email.
Cheers, Phil.
MG TF 160. (Protech Shocks with own design bearing carrier, own design big rear disc conversion & servo mount)
Jaguar X350 XJ6 3.0 (Pace with grace)
Mondeo Estate (Reliable old Donkey)
Honda Pacific Coast PC800 (Weird Bike)
Seat Ibiza DSG (wifes car)

willyphixitt
Posts: 527
Joined: Sun Oct 14, 2007 7:15 pm
MGF Register Region: Elsewhere
Model of Car: 2006(reg) TF135
Location: Jersey

Re: Standard TF Suspension Settings

Post by willyphixitt » Mon Aug 17, 2015 5:44 pm

Hi Phil,

Thanks for your input. Both VHS and Roger Parker suggest replacing the springs - like for like. However I have sent for some polybushes for the top end and some additional spacers from Rimmers. The car has only done just over the 17k miles. I hope to get round to seeing what I can do within the next week or so. I took a more accurate measurement since I first posted here. The readings are 338mm all round. I do hope to gain sufficient height to clear the low lip of the front bumper when negotiating these narrow speed bumps.

willyphixitt

flyingbanana
Posts: 459
Joined: Wed Oct 28, 2015 9:07 am
MGF Register Region: Yorkshire

Re: Standard TF Suspension Settings

Post by flyingbanana » Tue Jan 05, 2016 1:49 pm

Just to throw one in, what are ideal geo settings for a race car?

I really like the way my trophy handles is there any reason I can't use trophy settings on a TF on coilovers?

Cheers

Jase

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mgtfnut
Posts: 787
Joined: Mon Oct 08, 2007 2:22 pm
MGF Register Region: South Wales
Model of Car: TF 135
Location: Dinas Powys

Re: Standard TF Suspension Settings

Post by mgtfnut » Sun Jan 24, 2016 6:50 pm

adrianclifford wrote:Hi Jerry, of course, I know your car quite well as you know. However I'm intrigued as I thought your car sat quite low if I remember correctly from the last time I saw it (and you). As you are on different springs (I'm blue all round) and you are on the highest setting, what is your ride height ?
As I've been fiddling with the car recently, I checked the ride height - it's +/- 345mm front and rear. perhaps the colour makes it look lower Adrian!!

Bit late I know, but interesting all the same.
Jerry
MG TF 135 - 100k
Suzuki SJ 413 - 309k
Skoda Yeti SE 110 4x4 - 131k

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