The Pikey Posted May 13, 2010 Share Posted May 13, 2010 Had a great day at Curborough but I have a problem.. Since my last visit there I fitted a Titan LSD and now the car has awful under steer. It just seems really light on the front when coming out a corner and I have to back off the gas to get it to turn. Someone suggested I lowered the front which I did by 5mm and this did seem to make some difference but it's still not good. The car is an Academy sigma car with 6x13 CR500's, only a front ARB which is orange, a Titan LSD. The front camber looks right compared to others. Has the POBC any ideas other than me being a carp driver? Jason Edited by - jason fletcher on 13 May 2010 22:34:09 Link to comment Share on other sites More sharing options...
Drumster Posted May 13, 2010 Share Posted May 13, 2010 Jason, I'm no expert on car set-ups, but I owned my 7 for 10 years and then fitted an LSD and found that I, too, had a lot more understeer in corners compared to before. I only have a blue ARB on the front, but my '93 de dion does have a rear ARB which is on the 2nd hardest setting. I figured that with more rear end grip due to the LSD that this was just simply pushing the front on more. I've had to change my driving style so as not to carry too much speed into th corner. Just my 2p worth and would also appreciate any other views from more experienced LSD'ers Chris Alston C7CAT 1800 Supersprint R248 ....and then I jumped in Link to comment Share on other sites More sharing options...
Grubbster Posted May 13, 2010 Share Posted May 13, 2010 An LSD will tend to try to push the nose wide as it is trying to drive both rear wheels at the same speed - I too had some fun and games when I first fitted my Triton LSD last year. Suspension mods were part of the planned upgrade as well though and once these were finished the balance was restored once more - part of this included a rear ARB (in fact Freestyle adjustable ARBs front and rear). It is great again now. Solent Se7ens Web! Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted May 13, 2010 Share Posted May 13, 2010 Just want to check Jason... You are using the steering wheel correctly? Joking aside, I got my first understeery 'moment' the other day on a roundabout. Full beans apparently doesn't help turn in Take off the rear ARB, you don't need it anyway John _________________________ myothercarsa2cv Bugsy: '82 2cv6 😬 Talloulah '08 1.6K Classic Link to comment Share on other sites More sharing options...
Mark Durrant Posted May 14, 2010 Share Posted May 14, 2010 Jason If you are talking about understeer at Fradley hairpin then you need to be patient before applying the power. In addition, you can try trail braking to the apex keeping the weight on the front wheels, turn and then apply the power. Mark D Edited by - Mark Durrant on 14 May 2010 07:27:44 Link to comment Share on other sites More sharing options...
Jason Plato Posted May 14, 2010 Share Posted May 14, 2010 raise the backend 3 or 4 threads on the dampers here is my Duratec R .... C7 TOP Taffia AO Link to comment Share on other sites More sharing options...
Miltec Posted May 14, 2010 Share Posted May 14, 2010 Hope this helps Jason here VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
neilg Posted May 14, 2010 Share Posted May 14, 2010 Yep, trail brake to apex and then progressive power feeling the front grip . Don't be too hasty else you'll just push on forward. Link to comment Share on other sites More sharing options...
oldbutnotslow Posted May 14, 2010 Share Posted May 14, 2010 There are lots of variables involved in suspension set up so what I am about to say must be taken as general guidelines only and some may seem very obvious but are important none the less. There is no easy fix. It will take you some time and experimentation unless you happen to hit on something straight away. I don't know Curborough or the corner in question but assuming that the problem is: - 1) mid corner not on entry 2) that the corner is after relatively hard braking 3) and therefore the corner speed is relatively low Also I assume that you are running 6" rims all round. You may want to consider:- A) Tracking - setting the tracking to toe out or increasing toe out by say half a turn B) Increasing your castor angle by 1 washer (moving it to the back) C) Lowering the ride height at the front D) Camber settings 1.5 to 2 degrees negative E) Tyre pressure F) Tyre temperature G) Tyre age F) Rear ARB setting G) Front to aft rake is set correctly with the divers weight in the car H) Softening the front ARB (although an Orange bar is a very good starting point so may be a last thing to try!) Things to remember Do only one thing at a time. You cant be certain of what has caused the effect if you move 2 things at once Make notes of the effects and be sure to mark up things like spring platforms to allow you to count turns more easily. Lowering the front ride height will affect any flat floor/ corner weighting set up that you may have It will bring the sump lower to the road surface with an increased risk of grounding. Worn tyres will affect any camber reading on your existing set up. Swapping the rears to the front will help in getting a more consistent reading as they tend to wear flatter. Rear ARB has an interesting effect - try the softest setting first and move progressively stiffer A 3 psi change is a 16% alteration in the pressure if your starting point is 18psi. A 2 or 3 psi change can make a difference!! Old tyres even CR500' don't give anything like the grip of new tyres and can cause the front to wash out Putting fresh rubber on the front makes a heck of a dufference The BIB don't like you testing on the public roads!! Good luck Grant Taylor - Oldbutnotslow OBNS Motorsport Edited by - oldbutnotslow on 14 May 2010 09:59:00 Link to comment Share on other sites More sharing options...
The Pikey Posted May 14, 2010 Author Share Posted May 14, 2010 Thanks for all the input Gents. It's seems there's loads of things to try! I might be wrong but I'm sure I was faster around the track with a bog standard open diff.. cheers Jason Link to comment Share on other sites More sharing options...
Mavic82 Posted May 14, 2010 Share Posted May 14, 2010 From another point of view, rather than suspension changes what about diff changes. Excuse my ignorance but I am not familiar with the Titan LSD. What type is it and is it set up for a seven or anything with the ford diff? The wrong LSD charateristics can cause these issues as the lsd does not allow the axle to 'diff' enough acting at the wrong time like a solid axle. Just what you want when you accelerate, not when you corner. I have heard of others using the Titan LSD so it must be OK, just a thouht though. All be it not a great one when you have just shelled out. Guy Link to comment Share on other sites More sharing options...
irrotational Posted May 14, 2010 Share Posted May 14, 2010 Related to that there are always threads about ramp angles and torque biasing etc...the diff might be fine but the settings inside it are not? I'm afraid my view of diffs is a box of magic cogs --- my mind is blank.... Link to comment Share on other sites More sharing options...
The Village Idiot Posted May 14, 2010 Share Posted May 14, 2010 Rear ARB has an interesting effect - try the softest setting first and move progressively stiffer This is an interesting thing to say - my first 7 had no rear ARB and an open diff. It roll understeered like a pig on track and you had to wait an age before getting on the gas as the inside rear wheel would spin up. My current 7 has a rear ARB and a LSD, it has great balance into a corner and I can get on the gas so much earlier. When I bought the car, the person (a 7 race provider who had set the car up) said that the front end is controlled (partly) by the back end. It is such an easy upgrade to the rear ARB ? Dicks Link to comment Share on other sites More sharing options...
Racing Snake Posted May 14, 2010 Share Posted May 14, 2010 Hey Jason, give Nick Chan a shout. His Sigma powered academy 7 is very swift round Curborough. Cant remember if he has a LSD on that car but i am sure he can advise you on settings Mad Hatter Racing - Feel The Duralight R Torque 😬 Carl @ Penn 7's Link to comment Share on other sites More sharing options...
CSR7 Hillclimber Posted May 17, 2010 Share Posted May 17, 2010 Jason. Is this a s/h LSD that you have fitted with unknown ramp angles ? Suggest you sent it back to Titan for different ramp angles. Describe your symptoms and they can advise you and fit the required ramps and preload. CSR7 hillclimber Link to comment Share on other sites More sharing options...
The Pikey Posted May 17, 2010 Author Share Posted May 17, 2010 It's a brand new Titan from Road and Race. I have been keeping an eye on the preload on the LSD since being fitted. When fitted 43 flb After 35 miles 40flb After 100 miles 34 flb After 200 miles inc curbourough 29 flb All readings taken cold and by lifting one wheel off the floor, putting a torque wrench on the drive shaft nut so the reading will be slightly higher than they actually are hence the 43 when I think they come at 41 ish. Jason Edited by - Jason Fletcher on 17 May 2010 20:03:21 Link to comment Share on other sites More sharing options...
CSR7 Hillclimber Posted May 18, 2010 Share Posted May 18, 2010 Jason. Check with Titan what ramp angles they have fitted. They will be the best people to check it and correct the ramp angles to get it to work as it should CSR7 hillclimber Link to comment Share on other sites More sharing options...
CSR7 Hillclimber Posted May 19, 2010 Share Posted May 19, 2010 Jason. All things considered, sounds like you should reduce the preload. If correct ramp angles have been put in, you will find minimum preload say 5lbs will probably do the trick. CSR7 hillclimber Link to comment Share on other sites More sharing options...
The Pikey Posted May 19, 2010 Author Share Posted May 19, 2010 After speaking to Phil at R&R I have found out this is a known problem at CC. Aparently CC took a Titan equiped Sigma 125 to track (I think it was John Palmers) and had the same issue. They found out that the rear needed rising about 15mm! and then all was well. I'll give it a try soon. Jason Link to comment Share on other sites More sharing options...
mrl98 Posted July 1, 2010 Share Posted July 1, 2010 Any feedback? Have you managed to find a happy medium Jason? Link to comment Share on other sites More sharing options...
The Pikey Posted July 1, 2010 Author Share Posted July 1, 2010 Yep all sorted. It was the set-up. I never built the car and I assumed it had the correct settings i.e the flat front wishbones, which it had, and the 15mm higher back which it didn't. I raised it to 20mm on Phils suggestion and if anything I now have a tad of over steer. Just got back from Curborough and it's going sweet. Jason Link to comment Share on other sites More sharing options...
Pendennis Posted July 1, 2010 Share Posted July 1, 2010 Not sure I'd agree raising rear to 20mm FWIW, I have a Titan LSD via Phil, it took some bedding in to be honest. My S3 has 260bhp, uses 6" front tyres & 9" rears and has no rake, it is central bubble bang on flat level, it does not understeer one bit. If I was you I would look at your front end Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
The Pikey Posted July 1, 2010 Author Share Posted July 1, 2010 You might be right because as I said, if anything it's now over steering so i might lower it to the 15mm caterham recommend. Still drives really well though cheers Jason Link to comment Share on other sites More sharing options...
Pendennis Posted July 1, 2010 Share Posted July 1, 2010 15mm is still not level 😬 Why do you want rake? Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
The Pikey Posted July 1, 2010 Author Share Posted July 1, 2010 Because with rake it I can turn a corner and without it I go straight on Jason Link to comment Share on other sites More sharing options...
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