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-   -   Day out at Woodbridge (https://madabout-kitcars.com/forum/showthread.php?t=2352)

limpabit 27th September 2009 03:57

Day out at Woodbridge
 
Hi everyone.

Went to Woodbridge airfield today to meet up with Matt in his 5exi. Had a fantastic day there. Car was running low boost (about 7psi) but still managed on the straights to keep with the vx220 turbo's.

Matt's driving through the bents pushed the car to the limit (even spun without drama). And all this on the original mk1 suspension.

Quite surprised. No lift off jerking etc. Only difference at the rear I think is that the car has bigger and wider wheels. But handled great.

Got me a little worried now though. If you can break traction with low boost, when mine is on the road, I'm going to have to be very careful.

bigrich 27th September 2009 16:20

Any pics John?

limpabit 27th September 2009 16:31

Matt has some good ones and some video with camera attached to the car.
Once I get them from Matt, with his permission, I'll post them up.

sylvazx 27th September 2009 21:36

just joined the forum tonight and am a little worried by the stories of poor handling. i bought one of the very early cars ( 2nd batch manufactured ) and chose to fit it with the rover 216 ( honda ) engine. i find the handling of the car a bit nervous at the front but have not noticed anything from the back. when cornering hard on bumpy surfaces the front tends to wander off with each bump. has there been any suggested fixes for this problem at the front. am presently preparing a new engine to drop in the car over the winter, have sourcd a honda d16z6 engine from a honda crx, engine is the vtec version. have spent many hour refiguring the wiring to use the original ecu and fingers crossed it all works

john

limpabit 28th September 2009 04:52

Hi John.

Welcome to the forum.

I beleive Marlin changed the front end slightly and added an anti roll bar. Best to contact Marlin for all the changes. What tyre pressures are you running as this can have a big effect on the handling.

Ian (Merlinman) has done what sounds like the same engine as you (216 gti Honda dohc). But is finding it noisy at motorway speeds. So he will be interested on how your VTEC swap will turn out.

limpabit 28th September 2009 15:52

Found this picture of the Marlin. The picture does not do the colour of the car justice though. It's more of a pearlescent purple. Nice colour.

http://javelintrackdays.co.uk/jt/ind...=2205&Itemid=3

sylvazx 28th September 2009 20:12

Am running 20 psi front and 22 in the back. Have not done enough miles to experiment with the pressures. Had intended to fit a roll bar to the front as i quite like the back end a bit loose and that usually helps however this is not an easy car to make a bar up for due to location of the components at the front but will make an effort this winter when i fit the new engine and remove the fuel tank to have baffles welded in. Why Marlin would supply a tank in a car that can pull these g forces during cornering and not fit baffles beats me. Get fuel surge below half tank when cornering hard.

john

Ric H 29th September 2009 20:21

John,
Welcome along.
Does your fuel tank not have the standard Rover pump/swirl pot assembly in it? The pump housing incorporates a sort of jet pump pickup into a hinged swirl pot with enough fuel in to feed the pump for a long time so surge shouldn't really be an issue in that case, hence no need for Marlin to baffle the tank.

On tyre pressures, I think most people on here are running more like 15 - 18 front and rear so that might help. Tinkering with the steering arm heights to minimise bump steer pays dividends in improving the handling over bumps too - have a search on the forum for where it's been discussed before.

Richard

Dadiowe 29th September 2009 20:26

Poor front handling
 
[QUOTE=sylvazx;16896]just joined the forum tonight and am a little worried by the stories of poor handling. i bought one of the very early cars ( 2nd batch manufactured ) and chose to fit it with the rover 216 ( honda ) engine. i find the handling of the car a bit nervous at the front but have not noticed anything from the back. when cornering hard on bumpy surfaces the front tends to wander off with each bump. has there been any suggested fixes for this problem at the front. am presently preparing a new engine to drop in the car over the winter, have sourcd a honda d16z6 engine from a honda crx, engine is the vtec version. have spent many hour refiguring the wiring to use the original ecu and fingers crossed it all works

john,
Built my car about four years ago but i have not played around with it much. One thing i did resolve last year was the front handling. My car was suffering from "bump steer". Apparently when you go over a bump the steering arm geometry changes and pulls on the hub and moves the wheel left to right. You can get over this problem by adjusting the arm that connects the track rod to the hub. I believe it has an elongated hole for this purpose.
i jacked the car up removed the damper and strapped a laser level to the wheel, locked the steering wheel in a straight ahead position. Then where the point of light shone on the garage door i drew a vertical line. As i moved the suspension up and down i could see the point of light moving away from the vertical line showing that the wheel was being pulled by the steering arm. i then adjusted the link arm to minimise this movement. i did have to elongate the adjuster hole to get it spot on though.
i hope thats clear but if not let me know and i will try and be a bit more precise.

sylvazx 30th September 2009 09:29

Thanks for all the replies.
The fuel pump on this car cam from a rover 416 ( honda engine) and is separate from the fuel gauge and does not contain any sort of resevoir or surge pot. i may have therefore caused my own demise by using this pump. However i am removing the tank over the winter to fit baffles as the track days i want to do with this car have some long bends and due to amount of fuel used at these speeds feel i am safer with the baffles.
As for front suspension, yes the holes are slotted on steering arm and adjusted it to put track rod end in middle of the suspension arc of movement but may have got wrong. great idea with the laser to check toe in/out, got one for a xmas present and never used it, will give it a try.

alackofspeed 30th September 2009 11:55

Quote:

Originally Posted by sylvazx (Post 16912)
Had intended to fit a roll bar to the front as i quite like the back end a bit loose and that usually helps

From playing with the front and rear anti-roll bars on my car, a front ARB will promote understeer. That said, the rear suspension has some funny camber characteristics from factory, so who knows......

craig 30th September 2009 16:01

Quote:

Originally Posted by sylvazx (Post 16912)
Had intended to fit a roll bar to the front as i quite like the back end a bit loose and that usually helps

john


Quote:

Originally Posted by alackofspeed (Post 16938)
From playing with the front and rear anti-roll bars on my car, a front ARB will promote understeer. That said, the rear suspension has some funny camber characteristics from fatory, so who knows......


This is normally the case on all cars and the reason why marlin offer it, as the rear is very tail happy without one fitted.

limpabit 1st October 2009 10:04

Quote:

Originally Posted by sylvazx (Post 16937)
Thanks for all the replies.
The fuel pump on this car cam from a rover 416 ( honda engine) and is separate from the fuel gauge and does not contain any sort of resevoir or surge pot. i may have therefore caused my own demise by using this pump.

Funny that as Merlin man was getting the same with a Honda 216 GTI pump..

SDMC001 3rd October 2009 07:23

David

Welcome, I have seen all the comments regarding the front end issue, and all will help and surely make the experience more enjoyable, just wanted to add my though. Myself and others certainly buyng the earlier kits were supplied with 170 pound front springs, which are really a little soft, a number of us have gone upto 225/250 pound springs which doseem to have helped.

I have had my car setup recently by a race company and they have upped my tire pressures to 28 rear and 26 front, that though was based on the tyres I have, their thoughts are the tyre were not working for me so well at lower pressures.

The other thing they have done is to increase the number of clicks on the shocks, I was running at about 6 / 8 from fully open, I now am runnning around 20ish, its a bit bumpy but it has made a differance. Albeit if I went on long drive I would undo them to reatin my fillings.

bigrich 3rd October 2009 07:46

Hi Steve,

Note your comments on increased tyre pressure.......26/28...really is too high for this car; regardless of tyres. The below extract is from the VX220 forum for track pressures on R888, but the guide on weights is good :-

The pressures you use will initially depend on the weight of the car, too little pressure on a heavy car can lead to over deflection of the tyre and subsequent failure.

Below are some basic settings:

VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE
Very Light < 800kg 17 - 22 psi 22 - 29 psi
Light 800kg - 1000kg 20 - 26 psi 24 - 32 psi
Heavy 1000kg - 1400kg 23 - 27 psi 28 - 40 psi
Very Heavy > 1400kg 27 - 35 psi 37 - 40 psi


...for the exi we are definately in the top category


Rich

SDMC001 3rd October 2009 18:10

Rich

Thanks, I must say I had a similar debate with the company, I intend to lower the pressures a bit.

Interestingly, I have noticed the front wheels dont seem to lock up so easily, and the car does handle much better, but I will start playing.

Steve


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