Following on from my last thread with my front wheel lifting i reduced the front arb to the softest setting and increased the rear springs to 300 lbs, the front wheel still lifted and the body roll was quite bad again although front end grip felt really good.
I know the watts linkage style design of the JP sylva opposing trailing arms means that a rear ARB isnt required and the axle is supposed to act as an arb but i wondered if anyone had tried fitting an arb oon the rear with this set up?

it would be quite easy so i will give it a go and if it doesnt work i will look to go IRS.

Anyone know where i can get an IRS set up that would take a sierra diff and uprights with good geo. I can do the fab work to attach to the chassis

[Edited on 27-6-10 by Antnicuk]

Speak to Rob Farley via the clubstylus site...

Hi

In simple terms. Yes it has been tried. NO it doesn't work because the rear is already to stiff.

And the front end wheel lift. Just get a proper roll bar that is designed to work for the application. And ask your self why there's so many Rob Farley ones for sale SH. !!

Cheers Matt

I don't have a rob farley one, I have my own which seems to work as the roll was more when I softened it. There isn't a roll bar designed for my car as there is No other car using the running gear that I am.

My rear isn't too stiff, that's the problem, as I have a lot of roll which just a front arb can't seem to deal with. My front arb is very stiff! I have also just updated the rear springs to 300 lb ones

Any other suggestions? IRS?

[Edited on 28-6-10 by Antnicuk]

Hi

You need to get back to the very basics on this car. You are running way way OTT on rear springs. And then chasing problems round and round with adjustments at the wrong end. All the posts on various forums point to the fact that the car is so far from an ideal setup. The hardest springs ever run on the rear of a JP setup and successfully worked is 180Lb. Your running 300Lb !!!. Regardless of who's made the front ARB. its lifting inner front wheels. The ARB is way to stiff for the application. !!!

Cheers Matt

Are you finding lifting the inside front to be a problem? Massive understeer? What the wheels are doing is irrelevant if the car is handling how you want it to.

I'm sure i've posted that in one of your threads before but I can't remember the response.

Thanks for the replies, i know of people running 250 lb springs very successfully on a stylus, if i had 180 lb springs on the rear it would slam its back end on the deck every time i accelerate.

You cant compare my car with any other as very few sylva's have the sort of torque mine does and they are not running the heavier atlas that i'm running. Also, my engine is very far back compared to most, my prop is only a foot long.

My front wheel lifted even more when i didnt have a front arb so its not the arb thats too stiff causing the front to lift.

I will try the arb route and let you know how i get on.

As for how the car drives, i really like it, i have loads of front end grip, the back end is soooo easy to control and is extremely forgiving. I often take passengers out on track days and the response is always the same, even one who has a 300 bhp audi powered elise, who couldnt believe how much grip i had. You can step the back out and just hold your foot in and it will stay sideways with a little correction. I know thats not the quickest way to drive and the down side is the tyres over heat very quickly but thats my fault not the cars. But im not in for competition, just fun. With the 300 lbs on the rear it handles better than it ever has done, indicated by the speed i managed to take the fast left hand bend on Andy Walsh's activity day compared to all the well modded elises/exiges.
I would just like it to corner a little flatter....

I suppose the best thing to do would be let someone who knows how to drive take it out on track for a while and give me their opinion. They may like or may think its dreadful!

[Edited on 28-6-10 by Antnicuk]

FFS. Where's the banging head against a brick wall smiley.

your'e quite rude, im sure that cant be good for business, if you dont want to help, then please dont post. I apologise for not knowing and understanding everything about suspension but i am trying to learn by trying different things. This obviously stretches your patience.

Thanks for your help but you havent answered any of my points that contradict what you say?



[Edited on 28-6-10 by Antnicuk]

I'm not defending Matt, he's plenty capable of doing that himself if he wants too.

But;

I think the reason why people could be frustrated when offering help is because you seem to say (virtually in the same breath) "my car is the best with more grip and faster than this audi-elise and goes round corners better than this R500 etc. Then say it can't go round corners"...

When suggestions have been offered they appear to be not heeded and you do what you like - which is great, it's exactly what I do (might be why I'm fat with 2 driving bans and no friends mind, but it's still my call! )

My statement isn't just hear to antagonise you, quite the opposite - It's been suggested before that you take your car somewhere, Matt was suggested and I would still recommend even with his FFS comment! But when suggested you say, too expensive or too far etc, then you say you'd like to give it to someone who can drive. Well it's going to behave even worse for tem as you are used to correcting the appalling handling, but you still seem against taking it somewhere. It's almost as if you'd rather talk about how amazing or poor it is, than sort it!

Sorry, that last statement is almost def too harsh, but I don't know how to phrase correctly!

If it ain't broke don't fix it?

No antagonism here.

It’s difficult to try and explain your point on a forum without being misunderstood.

If we all just stuck with what worked we would be in the stone age, and i'm sure no one on a forum like this thinks "it works so I will leave it' We all want our cars to be the best they can be within certain parameters, mainly budget.

I do all the work to my car myself and I would like to continue and try to improve it. I'm not saying its appalling at all, far from it, but it can certainly be made better. (what cant) I said exactly that in my post about the R500. He was more capable and composed around the bends than my car, but then i’m comparing my car to one of the fastest cars of its type. I don’t feel you are being very fair when you say I have stated " my car is the best with more grip and faster than this audi-elise and goes round corners better than this R500 etc. Then say it can't go round corners"... as I have never said that but I see where you are coming from, as I said, its good I just want it better and I know it can be..... sorry


I know the car can be improved and I would like to try to do it (myself). If I took the car to Matt, (which I did consider) I would learn nothing, and as soon as I fiddled with it his settings would change and be gone for good. I don’t recall ever making excuses about not taking it to anyone, the above are the only reasons I don’t. I also suspect Matt's prejudice of the JP rear suspension design would hamper efforts to improve it.


If I were to have a conversation with someone about the car and they said the front arb is too stiff and causing the front wheel to lift, then I would say ok, but it used to lift more when I didn’t have an arb. you wouldn’t expect the response to be "FFS", you would have a discussion and hopefully the expert would explain to the lay person the why's and wherefores. I appreciate Matt's problem maybe something to do with the fact that he is a business and is reluctant to provide specification advice for nothing, especially in an open forum, and why should he, but please don’t get frustrated when someone inexperienced doesn’t understand where you are coming from.

My point is, when suggestions are made are made I’m too inquisitive to just sit there and accept it if things don’t make sense. Also, advice like, "get an ARB suitable for purpose" when the car is virtually custom built is no help at all without any more info on what would be suitable.

The ARB is adjustable, I soften it I get more roll, front wheel lifts, I stiffen it, I get less roll, front wheel lifts the same, when its not on there at all, it really lifts a lot and body roll is comical. But still not appalling !!

I have decided after a few discussions that front wheel lift isn’t too much of a problem, and I have eliminated as much as I probably can with the live axle and lots of torque, when I questioned it before, the general advise was stiffer rear springs, I tried it and I feel the car is better, despite being contrary to the norm. So when advice is given, I do heed it, as I did with the rose joints on the rear links, I was advised not to put any on and others said, I can do the chassis end but leave the axle end, so I did and so far I have had no problems.

As for you final statement, yes it is way to harsh, I don’t often post up for help, and you will generally find it is just after a track day, of which I only do a handful a year, while the issues are still fresh in my mind and I have studied the photos. The rest of the time I am working on improving the car and it never goes out the same as the last track day (which is some of the issue).

I am proud of the car, considering I built it, I am not a mechanic and its been a very steep learning curve and built on a sensible budget, I don’t ever say people are wrong but don’t persecute me for asking questions and wanting explanation to statements as that’s a little unfair.

Matt has said the rear arb has been tried and didn’t work, for the £20 it will cost me to try, I would still like to give it a go. I will then report back with my findings.

quote:

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Originally posted by Antnicuk
I know the car can be improved and I would like to try to do it (myself). If I took the car to Matt, (which I did consider) I would learn nothing, and as soon as I fiddled with it his settings would change and be gone for good

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Thanks for the reply, what does matt think? You know the basics of the car, do you think it's something you can work with and improve? Or is it an intrinsically flawed design?