Welcome to our resource for MG Car Information.
MG MGF Technical - For those of you who have lowered your F, a quick survey
|My car has been currently dropped to a 330 ride height (lowering knuckles). One thing I noticed is that on taking hard corners or hitting a significant bump at above 60kph or more, its sounds like the car might be bottoming out. Can't pinpoint the sound, but sounds like a quick sqeal of the tires possibly rubbing against the car body? Tires are 195/50/15 front 205/50/15 rear. If it is, should I be concern about tire or body damage. Its a very soft and quick sound so it doesn't sound like they are rubbing to hard or long. Should I increase the setting of my adjustable shocks or are AVO's just crap shocks? Should I get the car pumped up to 340 to be safe? Inquiring minds wanna know...|
Like to hear if anyone else with lowered F's have had this problem.
|Cince my MGF has been lowered (320mm), I have only problems with a scratch noise at bad roads.|
This noise comes from the lip under the front bumber, when it touch the ground. At harder jumps also the towing eye have earthcontact and this sound very terible.
for verfication of this lip, see
That is valid for MGF below app. VIN 9000 or in that area.
I'm still looking for a more precise date and VIN.
Also see thwe VIN survey site at
for more information and inputs
Torsten, do you mean I've to disassemble my 'nice' mudflaps if I go for the lowering ?
I drove at 280mm several miles when the right side HG-Unit got broken and realized a scratch then also at each little road bump.
|Torsten - hard jumping with your F??? I think you've been watching too many Evil Kneivel videos... What's next, jumping the Grand Canyon?(just kidding) |
Sorry for the confusion, I should not have used the words "bottoming out". I'm pretty much sure the car body is not touching the ground. Its sounds more like the tires are rubbing on something in the wheel wells when the suspension is compressed (hitting a bump). I'll investigate tonite. It looks like the clearance between the outside of the back tires and the outside part of the wheel well is very small and might be the source of the noise. Will do some more investigation tonite.
|@320mm the only problem I had was with the bottom grounding on speed bumps- none of the tyre interference problems you've noticed.|
I wonder if it is the front tyres rubbing up against the plastic wheel arch liners with steering lock- perhaps made worse by the low ride height. If this is the case, then the solution is simple: reprofile the liner with a hot air gun.
I guess there are plenty of other potential explanations for the problem- keep us posted.
|talking of jumping, how does the car handle bumps at speed in its new setup, in term of, keeping the wheels on the ground.|
I only ask after a nasty experience at the weekend on a country road when i hit a bumpy patch just as i wanted to drop my anchors and slam it into second for a nice tight bend. and the car was having none of it, the ABS made no difference, might even have hindered thing. The wheels simply weren't in contact with the road enough to stop it. luckily there was kind of a gravel track going straight (ish) on so i opted for that and ended an incredible 50 yards off the road, potentially quite silly i thought, and the huge pot wholes in the gravel track had made sure the Ģ60 on alignment a few weeks ago was wasted. I just wandered if the new setup could help keep the wheels on the road, or would it make it worse?
i guess an engine in the front would have helped.
|Isn't simply the suspension hitting the bump stops ?|
That sounds plausible ... and that's why these are designed for.
With no suspension, Dieter measured a ride height of 280 mm.
So, at 330 mm, that leave 50 mm before reaching the stops.
Maybe stops of a different design would allow some extra clearance ?
Powerflex makes replacement polyurethane bump stops.
|"I guess an engine in the front would have helped."|
Yes perhaps, though the sump might have been ripped out.
I was going to have mine lowered but with the speed humps through Oxford it would be Ģ60 a week for wheel alignment.
|One thing to remember is the pressure in the hydrogas system, this should be around the 400psi mark.|
at 330mm (with installed low knuckles) it my be about 360psi and never less then 340psi, is it ?
|For speed bumps I think 330mm is the absolute minimum especially if you have a K&N cold air pipe under your car or mud flaps (or even a splitter). For sensible road use, if you use it every day 340mm is as low as I would want to go.|
Other mods and adjustments will give you good handling results. I just had the polly bushes fitted and went for a toe in setting for the front wheels. This has improved the handling and road holding a great deal.
Other things that can improve stability are a front splitter. Some say that the rear spoilers/wings are effective but I think the jury is out on this at the moment (and my wife would leave me if I got one :-).
These mods will go long way to improving how the car responds and would be a way to go if you can't do it all at once (like me).
Of course these mods don't do much for the look of the car, my car is at 355mm just on the Hydrogas at the moment (looks ok).
I will lower it with knuckles one day but will only go to 340mm as I have to drive the car to work every day and I am surrounded by speed bumps at home.
I still need a splitter but I just spent a heap of money on the car and my credit card is crying. But first things first, another two front tyres please, 195's this time I think.
|Dieter, i always set the pressure to 400psi + or - a tad,if the pressure is set to 340 it does have a noticable effect on ride quality, if you have a good dentist this should not be a problem. |
|Thanks Mike :)|
.. relates to what I also found with my little experiance. About 340psi can IMO be the range where the units internal blade-spring powered valves may have their lowest acting point.
(very careful expressed, cause I'm not sure)
Anyway, I've still my first tooth :(=)
and would like to keep them as long as possible *g*
Tony, congratulations to your IMO wise decision according to the PU bushes. I really hope that your last years suspension problems will be off now :)
If all is adjusted well, then try the car at topspeed and sidewind. I think we all are interested in the results.
PS. .. the nights in Tokio last a bit long ? where is Mike, (Tokio) ? :))
|Dieter, it was Friday nite in Tokyo... always a long nite in Tokyo... :)|
OK, I think Fabrice was right. I think my shocks were set too low, and possibly the suspension is bottoming out on the bump stops. I've inspected the wheel well and tires and it doesn't look there is any rubbing.
Rob - this occurs even without being in full wheel lock.
MIke S. - pressure is still around 400psi's w/ lowering kuckles.
Tony - I use it as an every day commute car as well (albeit a very short 15min commute), but fortunately, there are no speed bumps on the way. I just have to take it real slow on the ramp down into the garage near the office.
But, I took a look at the K&N pipes Sunday while washing the car, and they've seen better days!!! I think I'll keep the ties. If they hit, you figure the ties will break rather than something else more expensive on the bottom.
Matt - I know what you mean. I had an almost similiar incident in my old set up (original Goodyears, original shocks, and 375+ride height!!). Hit a bump at 100kph going around a tight turn (a lot of it is my fault for braking late into the corner) and found the front tires skipping laterally!!!
Tires! get better tires! I'm amazed at the gripping power of the Bridgestones. Took the F out for a thrashing on some mountain road (plenty of S turns and hairpins), and was amazed. With the new suspension and tires, my VVC feels underpowered! Corners where the old Goodyears (with plenty of tread) would give, the Bridgestones didn't squeal at all. I found myself being able to accelerate out of corners a lot earlier than before.
Lowering definitely helps with highway stability. Before, the car got nervous at anywhere over 130kph (death grip on the steering wheel!!). Now, I find my F at 160kph feel like it did while driving 120kph with the old setup. No more skipping across the highway when you get hit by a crosswind.
Now for Don's rollbars...
|Thrashed my lowered S234 MLU through Italy last month -don't have the exact lowered measurements after new knuckles/shocks/hydrogas as above but I think you can see it on Mike's site (?!?!) wearing a pair of Spyder's too.|
Definitely a joy to drive: less effected by cross winds; considerably more assured at high speeds; looks like a proper car and handles as a sports car probably should.
This though may be the problem: twice managed to go round some sharpish bends very sideways (once upto Monte Cassio and once at night to Amalfi). My excuse was post-rain and skiddy roads, the girlfriend once she had stopped screaming accused me of aggressive driving and pushing too hard.
Probably an element of truth in this .... Luckily I dont have to daily contend with Islington's mad maze of speed bumps as it would be an impractical day to day set-up. SO once the planners have been left behind the eyes mist over .....
So my advice is get the bigger brakes too coz if looks a feels like a sports car you'll want to drive it like one !
Yup, that's next on my upgrade list... I will definitely upgrade the brake pads and then later I'll see if I need better discs. But looking at previous posts on brakes, appears most people are happy with the original brake discs, even for aggressive driving.
4 more days to the weekend...
|When my right suspension dropped to 300mm it became impossible to cross a speedbump without scratching the bottom of the car. What is to me the most dangerous part of 'over-lowering' your car is the front pipe. When my F was a while at 290mm due to hydragas problems (they never found out why it dropped so much), I destroyed my frontpipe within 2 weeks because I had to drive in to a parking lot, requiring steep up'n down driving towards other floors. Result was the frontpipe was ripped apart.|
So pay attention to that too!
And heavy cornering with my F doesn't creat any sound, only will hear screeching if I try to oversteer, but I cannot succeed in breaking out the rear of my F (even at full steering wheel turning)
|Scarlet has been up & down like a member of the oldest proffesion's undergarments!|
The lowest she has been is 310mm & at this height she would not negotiate speed ramps. Also, i lost 3 sets of home made cold air induction pipes.
Currently, she is riding at 330mm which is a happy medium. At this height she does not bottom out & i have yet to hear the tell tale sqeak of the rear tyres rubbing the wheel arches under heavy cornering. It was this problem that caused minor body creases in the rear wings (cue dent devils, if i ever get round to it!) These creases are appearing on the Techspeed lowered F's i have seen as well...
The reason my wheels can rub the wings is that the TSW blade wheels have a greater offset from the hub than the standard wheels. This has set the lower limit on the ride height of Scarlet. If you are experiencing wheel arch rubbing with standard wheels, maybe the subframe isn't correctly aligned? Anyone know if this is possible?
Hope this helps.
|Andrew thanks. Yes I recall you had blade wheels installed. I had the alignment checked after the suspension work so I don't suspect a mis-aligned subframe.|
The noise is still a bit of a mystery to me. Its a very subtle and quick sound which occurs when I hit a sudden bump with good speed. I was incorrect about the hard cornering as I've tried to repeat the sound on flat corners with no success. Something I can live with, but always on the back of my mind...
Would the shocks bottom out first before the suspension does (bump stops hitting)? I've tried raising the adjustments on the AVO's to a stiffer setting, but still get the sound one in awhile. The mechanic at the garage (that installed the AVO's and lowering knuckles) seems to think it might be the shocks. He then went on mentioning the shortcomings of AVO's (in his experience). Thanks - the sales people could have told me that BEFORE I bought them.
Starting to regret not paying the extra money for Bilstein shocks... Meanwhile keeping an eye on my
maybe you you could do a simple test : put some paint on the bump stops, take your F for a ride and then look for traces of paint ???
|Fabrice - I have to refresh my memory. where exactly are the bump stops located in the suspension (I don't have a F workmanual)? I would presume they are separate from the hydrogas units, as their purpose is to protect from the collapse of the hydragas spheres.|
Here is partial picture of the F suspension showing the lower part of the hydrogas, knuckles, and dampers.
Does anybody have any detailed diagrams/ photos of the F's suspension online?
I may be wrong, but I think that, on your picture, the bump stop is the "cone" on the right of the damper (top - middle of the picture)
|Fabrice is right|
|Have followed the discussion in this thread re low riding height. My problem is the Rover dealer sold me a brand new F five weeks ago from shop with 300 mm riding height on both front and rear. Have hit the ground several times even in low speed. From reading all mails in this thread I understand that this is too low for being standard and I must let dealer garage to rise the height at first service. What is "standard" height? Can I pressurize the gas chambers myself?|
My question is if this modification also will automatically soften the suspension which I find too hard. Tyres are Goodyear Eagle Touring front 185/55 R15 and rear 205/50 R15. Tyre pressure is 2.0 kg/cm2 recommended from service book. I am not driving in motorways but on snakey roads and in cities.
Will any friendly person comment on this. Thanks in advance.
Basically your car is far too low (probably looks great though!)
Ride height is measured from the centre of the MG badge on the wheel to the wheel arch lip vertically above. The manufacturers range is 358-378mm (measured with an ambient temperature of 17C).
You cannot raise the suspension yourself unless you have access to a hydragas pump, so return to the dealer and ask for them to correct the ride height.
And to follow up Robīs answer - Yes ,the suspension will be "softer" in a way when system is pumped up to correct level. As Your car is brand new this is a dealer job, I have a pump of my own which is very handy! Lower ride height can still be achieved safely but then with lowering knuckels, see archive.
Feel free to phone me, member 2171 in M.G.Car Club of Sweden.
This thread was discussed between 02/06/2000 and 13/06/2000
MG MGF Technical index
This thread is from the archive. The Live MG MGF Technical BBS is active now.