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spring rates
danny84 - 20/8/13 at 01:21 AM

My MK Indy is currently running a 4xv R1 engine with Protec Adjustable shocks.When i go out for a spirited drive with other mates in their various bec/cec i feel as though at times the car is all over the place over bumpy roads compared to theirs giving me no confidence to push it without getting thrown about.

I bought the car already built so have no idea what rate of springs are on.
It has 15 inch wheels with tyres running about 18 psi.

I have tried adjusting the dampers but it doesn't make any notible difference.....so.....Can anyone recommend the correct poundage of springs that are more suited to road use without compromising cornering performance,also is there anywhere in the northeast of england who could set the car up correctly?
I know its a bit of personal preference type of question but i would go with the majority.

Cheers in advance
Danny

mark chandler - 20/8/13 at 07:10 AM

First thing to consider is bump steer, it's been covered on here loads of times so have a search.

Have you got this? Quick check bounce the front suspension and watch the wheels, if they turn in and out at all when doing this you have your culprit.

GeoffT - 20/8/13 at 08:30 AM

Also don't overlook tracking, I've found these cars can be very sensitive to even small tracking errors, making them dart around somewhat on uneven roads.

danny84 - 20/8/13 at 02:21 PM

ok cheers i'll check both as soon as and get back

pewe - 20/8/13 at 02:24 PM

You could do worse, if funds allow, taking it to Procomp for a proper setting up.
Matt and Ivan charge something over £200 to spend as much time as it takes to achieve the optimum set-up for your use including tuning Protech shocks by firstly dynoing them and then changing the oil for something which works better with out type of car.
Procomp are on here and all reports from customers (self included) praise their services highly.
HTH. Cheers, Pewe10

loggyboy - 20/8/13 at 02:25 PM

Adjusting shocks should make a really noticeable difference. However, I do recall Matt (procomp) or one of his customers posting up recently about how limited the adjustment of alot of shocks are, IE, only 5-6 of the settings of a 24 point adjustment are the ones that matter. So if you havent already, set the shocks in the middle and work up or down one or 2 clicks at a time to see if that helps. Also try taking a few psi out the tyres.

[Edited on 20-8-13 by loggyboy]

danny84 - 20/8/13 at 03:01 PM

I have checked the bump steer and there doesn't seem to be any notible movement in the wheels or movement of steering wheel.I took a video on my i phone for a 3rd person perspective.I'll get the tracking checked tomorrow and let a few psi out the tyres.Then set the dampers back to 5 clkicks out of 10.
We're of out for a fish and chip run to whitby on sunday so i'll see how it goes.

loggyboy - 20/8/13 at 03:08 PM

quote:
Originally posted by danny84
I have checked the bump steer and there doesn't seem to be any notible movement in the wheels or movement of steering wheel.


Bump steer isnt really something that can be measured without using proper equipment.

Custardpants - 21/8/13 at 02:27 PM

Check to see if you have any toe out especially on the front, this gives the car an unsettled feeling. I have 350lb springs all round and without anti roll bars, it definitely needs stiffer springs at the back for track use.