Zircon Posted February 24, 2016 Report Share Posted February 24, 2016 Hello chaps You may remember the last time I came to you with my Blue MR2 Turbo a few years back - you fitted some RCA's and new track rod ends that needed the knuckle drilled to fit them but this lowered the car quite a bit, my coilovers were seized and you had to cut up some spacers to get me enough clearance to reach home Anyway - I learnt my lesson about coilovers and - they need to be adjustable when changing the suspension setup! My coilovers are always kept greased with ACF50 grease now. I subsequently ran some Tein Super Streets and am now running a set of Japanese import Ohlins PCV coilovers that have been sprung and valved to match our shonky B-roads! I have also fitted some very light 17" Desmond Regamaster forged wheels 8" et+35 fronts and 9" et-38 rears. I have had the car setup by a local company that prep track cars etc - Jtech in Reading and am very happy with the service I got. The only thing I would like to change if I could was to get the front camber down from -2 degrees to -1 degrees as the front is very darty. Jtech have said that -2 is the maximum they could do due to the front wheel size and coilovers. You guys have probably seen a fair few MR2's over the years with similar setups and I wonder if you reckon you could reduce the front camber any more than this and how you could achieve it? I think realistically I am stuck with the physics of the setup but if anyone knows you will! Cheers Rob Quote Link to comment Share on other sites More sharing options...
Tony Posted February 25, 2016 Report Share Posted February 25, 2016 Hi Rob and welcome back..... How are they adjusting the camber is it via the coilover top mount or is it via the strut pinch bolts? Quote Link to comment Share on other sites More sharing options...
Zircon Posted February 25, 2016 Author Report Share Posted February 25, 2016 Hi Tony The top mount is on full negative, the strut / hub connection has oval holes and is pushed right in (I think) and I then have camber bolts to bring the wheel away from the spring by about 5mm. The 8" wheels (et35) are perfectly flush with the arch now.... I know it is all quite tight but I've seen others with coilovers and the same wheels / offset running less than -2 camber. The strut type is not one of the new monotube types - do you think that would make any difference? I measured the springs on my Ohlins and they were a smaller diameter than my previous Super Streets...... I guess you would need to see it really - just wondering if you know it is possible to get less camber with such a setup...... Quote Link to comment Share on other sites More sharing options...
Tony Posted February 26, 2016 Report Share Posted February 26, 2016 Getting less camber should be easy if the top mount is adjusted in toward the engine ( if there was one there ) the only spanner in the works is if the EZ cam becomes an issue moving the coil away from the wheel? Quote Link to comment Share on other sites More sharing options...
Zircon Posted February 26, 2016 Author Report Share Posted February 26, 2016 Cheers Tony When my holiday leave is refreshed I think I will bring it over to you for a second opinion. Rob Quote Link to comment Share on other sites More sharing options...
Tony Posted February 27, 2016 Report Share Posted February 27, 2016 Looking at what the job involves costs nothing..... I take it you do have EZ cams fitted on the struts? Quote Link to comment Share on other sites More sharing options...
Zircon Posted February 29, 2016 Author Report Share Posted February 29, 2016 Yeah Eibach cam bolts on front and rear of car for maximum flexibility (plus I acquired them for free so chucked them on before the Geo.....) Quote Link to comment Share on other sites More sharing options...
Tony Posted February 29, 2016 Report Share Posted February 29, 2016 In that case i can't see a problem because the top mounts have a +- 3 degree range and the EZ bolts around 1 degree 30'. Quote Link to comment Share on other sites More sharing options...
Zircon Posted February 29, 2016 Author Report Share Posted February 29, 2016 I think the issue is flushness - add negative camber at top mount, draw it back again with eibach bolts = spring contact to tyre. Where I reckon it might be possible to snatch a bit of positive camber back is the tolerance they have allowed between tyre edge and spring. If they've left say 5mm so you reckon you could safely get closer to the spring? Quote Link to comment Share on other sites More sharing options...
adam_r Posted March 1, 2016 Report Share Posted March 1, 2016 If you draw too much camber in in the top mounts, can you not then apply 'positive' camber to the cam adjuster at the bottom of the strut to then keep the tyre away from the coil? Or even better, give max positive camber the cam adjusters provide then try and dial in to the correct negative camber using the top mounts Quote Link to comment Share on other sites More sharing options...
Tony Posted March 1, 2016 Report Share Posted March 1, 2016 Bloody hell i'm out of a job..... Well said adam. Quote Link to comment Share on other sites More sharing options...
adam_r Posted March 1, 2016 Report Share Posted March 1, 2016 Thanks Tony Quote Link to comment Share on other sites More sharing options...
Rich Posted March 1, 2016 Report Share Posted March 1, 2016 Aren't you looking for a new job Adam! Nice MR2 Rob, you don't see many about nowadays 1 Quote Link to comment Share on other sites More sharing options...
adam_r Posted March 1, 2016 Report Share Posted March 1, 2016 I thought what i sais was basic geometry though? I would have though that the tyre was touching the coil even before changing camber at the topmount? Changing camber at the top mount wont make the distance bewteen the tyre and coil and different as they should alter as one. Only the cam adjuster will effect the distance between the tyre and coil Quote Link to comment Share on other sites More sharing options...
Zircon Posted March 1, 2016 Author Report Share Posted March 1, 2016 Good points fellas (appreciate the thought that you are kindly giving this) however I reckon my offset of -35 is the issue. -35 is the perfect flushness with the MR2 front arch (with stock struts (not sure about colovers but I assume it is the same as the hub is retained as original). If I put maximum positive camber on the cam adjusters and then use the top mount to make it more negative I am pretty much guaranteed to end up with the tyre sticking out proud of the arch I reckon? Also, if the topmount is on max. negative setting and the cam adjusters are set to maximum flushness (positive positioning) then I think I've reached the limits of my adjust-ability? Quote Link to comment Share on other sites More sharing options...
adam_r Posted March 1, 2016 Report Share Posted March 1, 2016 Zircon... You need to take my comments with a bit of common sense. I think your best bet is to do the following: 1) adjust the top mount setting about 3/4 way to full negative camber(this does not need to be exactly 3/4) 2) stick wheel on and see where you camber lies..... Then use your cam adjuster to dial in the negavitve camber till its almost there ( check clearence between tyre and coil) 3) use the top mount adjuster to fine tune your camber. Both adjusters play a part in how the camber effect the hub angle in relation to the strut angle. Both important and both need to be adjustef in unison Quote Link to comment Share on other sites More sharing options...
Tony Posted March 2, 2016 Report Share Posted March 2, 2016 Becoming an interesting topic.... Issues of concern here is one to regain the camber and two to maintain the wheel to coil clearance both topics are an easy cure but there's another issue "the scrub radius"... SAI aka Steering axis inclination or KPI aka king pin inclination along with the camber project the cars weight to specific point within the tyres contact patch. Historically this point should be under and/ or within the wheels lower pivotal point aka pick-up point. If the camber is moved via the strut toward positive then the SAI will reduce moving the scrub radius toward the inside of the wheels pivotal point, To most this would all read like a "so what" moment but there are consequences if the SR is placed incorrectly..... In no particular order of importance 1: Mechanical wear due to un-uniform loading would be increased 2: SAI projected inboard of the SR increases steering effort, reduces steering return and generally adds unwanted weight to the steering feel. 3: SAI projected outboard of the SR murders all of the above but includes steering vibration ( violent with additional speed ) plus violent tram lining. Lotus and my beloved Esprit got it very wrong.... The SAI target datum was never released but I measured it at 12 degrees 45' but with a positive camber position, this projected the SR inboard of the SAI rather than under it..... This meant the steering at low speed was for male hands only, it was really that heavy. The steering feel was dead at speed and the tyres hopped when turning on full lock. Quote Link to comment Share on other sites More sharing options...
Zircon Posted March 4, 2016 Author Report Share Posted March 4, 2016 And this ^ is why I will be coming back to you guys. So much more about Geo setup than I ever expect! Thanks Tony, I will probably bring it up in June or something so I will refresh this thread to jog your memory..... Cheers Rob Quote Link to comment Share on other sites More sharing options...
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