Henry Boler Posted January 19, 2017 Report Share Posted January 19, 2017 Whilst I'm on the topic of suspension at the moment, I wanted to ask about lowering. I would like to lower the front end of my car (1971 MK3 GT6) between 1" and 2" as it is way too high. What is the best way to go about it? Currently I have a set of GAZ ride adjustable shocks combined with who knows what springs. Is there anywhere that sells shorter springs? Henry Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 19, 2017 Report Share Posted January 19, 2017 Fitted spring lengths are in the manual , (thats out in the conservatory with a cold laptop) but first thoughts are that your shocker spring platforms are at the wrong height from the lower bush. rather than the springs are too long. pete Link to comment Share on other sites More sharing options...
Henry Boler Posted January 19, 2017 Author Report Share Posted January 19, 2017 Just dug through my history file to find the front shocks are from TRGB Ltd. Part Number TRGB299/A and no reference to that on their website... Does anyone know the dimensions for the spring platforms then? Henry Link to comment Share on other sites More sharing options...
Henry Boler Posted January 19, 2017 Author Report Share Posted January 19, 2017 Link to comment Share on other sites More sharing options...
GT6M Posted January 19, 2017 Report Share Posted January 19, 2017 Go t,thees blokes, an get some decent springs and can be powder coated to any colour ye like, blak is standard, butt, want another shade, then they are done twice, so twice as much protectionee for normal road use, go for 500 for sporty use, go for 650 or moer 500,s will be fine, esp as ye got adjustables forget aboot any thing less. as it lets car float too much D Faulkner Springs LLP M Link to comment Share on other sites More sharing options...
JohnD Posted January 19, 2017 Report Share Posted January 19, 2017 Henry, There must be hundreds, no thousands of places that sell coil springs for performance cars. For instance, Demon Tweeks, sell nearly 500 different springs of different lengths and stiffnesses, and that's just in one diameter from one manufacturer! Don't go to DT - expensive - find a shop near you that sells them. But you have adjustable shocks - is that stiffness adjustable, or height adjustable? Is the a thread around the body of the shocker, with a ring on which the spring sits, so that you can turn the ring, lowering or raising the car? You would need two "C-spanners" to do that adjustment. They engage in notches in the ring. If you don't have adjustable spring seats, then you need a shorter spring, BUT that spring must be stiffer too, or else a bump that would have done no harm, will let the car 'bottom' on the road. The original GT6 springs were 220 "pounds/inch" in stiffness. This means that a weight of 220lbs will compress the spring one inch. To lower, typical values would be: "Road Lowered" 330 lbs.in "Sprint" 480 "Race" 650 The last will give a very hard ride indeed! And do check that a fixed lower spring seat is at the correct height. Many people in the past have been misled by dampers with too high a seat, sold as for Triumphs. Seems unlikely that TRGB would sell such things. John 1 Link to comment Share on other sites More sharing options...
GT6M Posted January 19, 2017 Report Share Posted January 19, 2017 "Race" 650 The last will give a very hard ride indeed!................... Sorry John, but it dont, they are just fine The inclination of the Spring, dictates that a much stiffer spring is needed as to a verticle spring, this also applies to a shocker, set a shocker on an 40 deg angle to 8 clicks now put it on a straight up position, and its alott lott moer hard. this is why the Standard GT6 is way too soft up frunt and even so wid 330-450 lbders too M Link to comment Share on other sites More sharing options...
Clive Posted January 20, 2017 Report Share Posted January 20, 2017 Thinking back, I ran theCC 440lb -1" springs on my vitesse for many years. That was an every day car (6-8k a year), and it never felt floaty but seemed to handle well (bearing in mind the poor weight distribution!) I have a spitfire now, and that is running 480lb springs. A touch firm for a daily driver, but not too bad. And helps with the cornering.... Personally (sorry Marcus) I would look at 450-550lb springs, And work out what fitted height you want and from that you should be able to calculate the "free length" Using the data from above, about 880lb per spring, so a 440lb spring would be compressed by 2", a 500lb by 1.75 and so on... Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 That all sounds like rather too much to choose from to me! I've got ride or stiffness adjustable shocks on my car, not height adjustable. Looking at the photos on Rimmers of the height adjustable version of my shocks, if set to the lowest position they don't look much like they'd make the car any lower to me... My car handles extremely well, and believe me, I push my luck sometimes! I don't want to ruin that, but it would look better an inch lower! I noticed that Canley's sell one "F67 - FRONT SPRING - 330LB 1" LOWER" anyone tried these?. Henry Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 Henry, When you say Adjustable Ride Do you mean height and or damping? If the spring seat on the damper has a thread and locking ring then its a height ride adjuster and it maybe set to high. See Pete and John's comments. Dave Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 As I said above, the damping is adjustable, the height is not. I have a small knob on the bottom of my shock, that is all. Henry Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 20, 2017 Report Share Posted January 20, 2017 manual s a bit vague but gives GT6 front springs as fitted test length as 8.06" +- 0.09" test load 880lbs free length 12.46" there's no clues about spring plate on shocker positions pete Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 Are the camber and tracking correct as both of these will influence the height. Dave Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 I'll dig out an old standard spitfire one and check the measurements, I believe they are the same. Interesting thought about the camber and tracking, the answer is I don't really know. I think the tracking is good, I did it myself 2 years ago with string etc. and tyre wear has been good since, but camber, never really got round to doing that... How much of a difference are we talking? Henry Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 If the front wheels are tucking in at the bottom it will push the height up maybe an inch. If the front wheels are sitting flat and upright plus no tyre wear on the outer tread then the camber is probably OK. Dave Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 Just a thought has anybody fitted a spacer, between the seat and spring, at the top or bottom of the springs. Dave Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 I've got the car with me at work, so I'll pop out and measure the springs at some point. It might be possible that the wheels need pushing out at the bottom a bit. Need to have a good look on level ground to be sure. There were some crude spacers and things, not matching on either side before I rebuilt the car, but now nothing but the spring in there. Shock absorber plate at the bottom is touching the spring, then theres the top plate on the sping which is bolted straight to the suspension turret. Henry Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 The springs should be, as you say, touching top and bottom mountings/plates. Where the wishbone suspension brackets mount onto the chassis there should be spacers. Three to four on each mounting point. These look a bit like a flat tuning fork. Open one end. Dave Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 Okay, on the wishbones, I only have one shim per bracket on all four. I did, however, buy lots of them for when I got round to doing it properly, and they are all stainless so no rust issues. Adding shims would definitely work out a lot cheaper if that is what needs doing! Henry Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 So, my coil springs measure around 8.75", a bit more than the 8.06" specified! Henry Link to comment Share on other sites More sharing options...
dave.vitesse Posted January 20, 2017 Report Share Posted January 20, 2017 One shim all round does not sound enough for the standard set up. On an average three would be the norm. But you could get the camber checked before hand. Dave Link to comment Share on other sites More sharing options...
Clive Posted January 20, 2017 Report Share Posted January 20, 2017 You can do a basic check on camber using a spirit level and a bit of wood that is cut to length so it fits against the tyre rim (just inside from the edge) A tiny bit of negative camber is ideal. If you adjust camber it will put the tracking out. But easy to correct. 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 20, 2017 Report Share Posted January 20, 2017 8.75" that probably gives you a ride height gain of around +1.5" at the wheels Wow !!! well you'll never graze the down pipes Pete Link to comment Share on other sites More sharing options...
Henry Boler Posted January 20, 2017 Author Report Share Posted January 20, 2017 So it looks like I need to get new springs and have a look at the camber then. Henry Link to comment Share on other sites More sharing options...
JohnD Posted January 20, 2017 Report Share Posted January 20, 2017 Marcus - you are a harder man than me! 650Lb springs make for a harsh ride in SofS! Henry - Don't be diverted by the talk of camber. Camber is important, and adding more wishbone bracket spacers will produce more negative camber but not lower the car significantly. Don't rely either on the original camber settings, which were for crossply tyres. Modern radials with more flexible side walls benefit from some negative - one degree minimum, IMHO. John Link to comment Share on other sites More sharing options...
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