nickson motorsport 944 turbo track car build

[nicksonmsport]

exactly as you say mate, there is a huge amount of crap on the internet, which people read and take as gospel, u have to take internet advice and information with a pinch of salt. speaking with someone who has done the conversion and had great results is far more valuable than reading what a 14 year old child may have written on the net lol!

i agree different people may have had different results, but who is to know if they carried out the conversion correctly, or had any of the suspension setup correctly, the fact the car handled like crap might just mean they didnt have a clue what they were doing. i have built race and rally cars for 10years and so have a good understanding of setup and what works and what doesnt, coupled with engineering knowledge and experience i have a far better chance of getting a car set up right than someone ''having a go''

the torsion bar setup on the 944 is something i have not dealt with before so i am learning its pro's and cons and thinking of ways to make it more effective or simple, if something is complicated it makes setup much more difficult. pairing up torsion bars with coilover springs is complicated when it comes to suspension compared to just running a simple coil and spring setup with trailing arms, and is a setup that is proven and common on many cars anyway. all you need to do to make it work on a 944 is make sure when you remove the torsion bars that you put some strength back in that the torsion setup provided.

 

[edh]

Will be interested to see the results (and costs) - I expect all those bushes will work out quite expensive

I think there's plenty of racers in the US running without TB's

 

[nicksonmsport]

the rear end bushes work out at about £400 all in from the us. that is for 4 polybronze bushes for the main torque tube and spring plate, and 2 monoball bearing bushes where the trailing arms attach to the centre of the axle. i will also replace the front end with spherical bearing bushes on the a arms. although i have a cunning plan! which will cut the cost of bushes down to around £200 on the rear which isnt far off the sort of money you would spend putting std polybushes in. you shall see my plan evolve as the project progresses.

i would machine up some custom bushes and spherical bearings but tbh i would spend nearly as much doing it myself as just buying them from the states. and this way it saves me a huge amount of time that i can spend building the car instead.

tbh i have no issues spending £3-4k on suspension and brakes as on a track car this is far more important than power! (obviously as i am carrying out all the labour myself i am saving a huge amount over what a customer would pay, so i dont mind spending extra on components.

 

[nicksonmsport]

spent a bit of time today swapping some tyres onto the azev wheels and offering them up to the car with the ride height set at a level close to what i will run once the coilovers are fitted. mainly to see where the wheels sat on the car due to the low offsets.

i set the camber on the front to max on the m030 hubs, which provided only around 2 degrees, the rears will need adjusting on the eccentric bolts as even at ride height its only 1 degree.

the rears i will get away with once the camber has been set up. the tyre will arc up into the arch with clearance, worst case is a very slight arch flare to maximise clearance.

the front is a bit more of an aggresive fitment and even with more negative camber i will likely struggle to get clearance on compression. there are a couple of options. one is to fab custom ally front arch extensions, the other is to machine the mount face of the wheel to bring the wheel in by changing the offset. (currently et15) maybe with slight machining of the wheel and slightly more camber i will just about achieve enough clearance. with the coilovers i dont expect a huge amount of suspension travel, but it will be useful to have some clearance if its needed.

i also started fabricating an ally centre console to mount the battery cut off, extinguisher pull chord, heater panel and a few other toggle switches. pics to come of this once complete

thanks
nick

 

[944 man]

I think that youre going to need wheels which are closer to the correct offset. Widetracking can work with series one racers and standard 7" x 15" ATS wheels, but larger diameters foul badly and they drive like sh*t.

GRP flares are quite common in America and a set will certainly clear the wheels that youre currently using, although they wont make it any nicer to drive.

You used to be able to buy a set for $200/£100, but I suspect that theyll be a good deal more now. The fellow who produced them at that price went out of business IIRC.


Simon

 

[nicksonmsport]

there shouldnt be any issues with fouling, there is plenty of clearance on full lock on the fronts, as remember hard springs will be used as this is a track car more than anything else, so suspension travel will be minimal.

i do like the look of those arches, but i would prefer not to use them really as to make them work properly it means cutting the rear 1/4 up. we shall see if i can make these wheels work. those arches are available from broadfoot racing in the states but around £500 shipped to uk.

with regards to the car driving like crap, unless its specific to the 944 i have driven many cars with widetrack setups with offsets nowhere near the standard values and although the car may drive slightly different, its more an issue on the road due to tramlining, and on track its not something i have found causes much concern, its certainly something that you adapt to and doubt will notice once your used to the car with that setup. tbh pretty much every serious race/rally car out there run much wider setups than standard. it will make almost no difference on the rear end, and the only noticable difference on the front is that the arc of the steering is slighly larger rather than twisting near to the centreline, the wheel may arch slightly forward/backward in the arch on turn.

we shall see how the car handles once up and running. if there are any issues they will be addressed, but there are many racers in aus/usa/nz running stupidly low offset wheels and silly wide tyres with no issues. have seen cars running 11j up front and 13j at the rear!

 

[Neil Haughey]

Scrub radius goes from -ve to +ve with big widetracking, does on my race car with 20mm spaces as ISTR stock is something like 13mm -ve. On track I actually feel like its an improvement as it amplifies the steering feedback forces, does make the car very physical to drive though without PAS. Can go from fairly light and easy (loads of -ve camber makes it light straight ahead) to very physical in a split second. Just set the castor how you like to get the sort of turn in feel you want.

 

[nicksonmsport]

yeah as you say it can increase feedback through the wheel. i will likely be keeping the power steering as well so its wont be to much like hard work to drive.

i have a bmw 635csi which im also building into a touring car replica, this runs et20 as standard, i have swapped the wheels to some which are now equivalent to et-10 with the spacers. so a difference of 30mm over stock, and the car drives absolutely fine. the only downfall really is wheel bearings can wear quicker due to the leverage effect.

but this is a race/track car, so i expect things to wear out quicker!

out of interest, what sort of camber do you run front and rear on your race car.
thanks
nick

 

[nicksonmsport]

bit more progress today.

finished of the ally centre console which houses all the switches/pull chords etc. that just needs to be attached to the body once the interior is painted

i also fitted the harness points to the floor for the 6 point crotch straps, and 2 points on the trans tunnel for the lap belt. the sill already had a suitable fixing point. rear harness straps will be fitted to the cage.

the fixings consist of 3mm plate with welded 7/16unf captive nuts. the ones on the trans tunnel are welded to the inside of the trans tunnel. the crotch points are welded onto the box section areas of the floor pan with captive nuts inside.

i also made a start fixing the extinguishers to the floorpan

hopefully more progress to come soon.
thanks

 

[Neil Haughey]

Camber will be anywhere between 3.5 and 5 on the front with about 1 degree or so less on the rear than the front. Varies from car and driver, tyres etc. I haven't honed in yet on an ideal number for me. My opinion on it is guys who steer in hard need more camber as they generate more roll, I tend to try and not drive like that preferring to gently ease the car into a corner. Thing is though with an LSD you definitely need to chuck the car at the corners more than is natural for me i.e. turn in later and harder, which generates more roll etc. etc. As a side point Michelin for example say not to use more than 4 -ve on the cups but there are definitely guys running more here and ISTR some of those racing stateside have gone up to 5 -ve or more as well.

 

[nicksonmsport]

ok thanks. i reckon running 4/5 degrees of camber the wheels should just about fit under the front arches. if not then i may machine a small amount from the wheel mount face.

hopefully make a bit more progress on the car today

thanks

 

[944 man]

Isnt five degrees of negative camber going to crucify your tyres?

 

[nicksonmsport]

your right negative camber will wear tyres quickly. but if thats the sort of camber required to make the car handle well on circuit then thats just something you have to deal with! i doubt i will run 5degrees, 3.5/4degrees should be plenty and is the standard sort of camber race/track cars run. im not running camber to get the wheels under the arches, im running camber as it is a geo setup that is required for a track biased car. if it brings the wheels under the arches then thats a bonus! if it doesnt, then i will have to create more clearance in the arch using arch extensions, or slight machining of the wheel face.

 

[944 man]

I understand the point of negative camber. My point was that five degrees could cause the tyres to fail, not simply wear. A little overly cautious on my part perhaps, but five degrees is certainly border-line, I think.

 

[944 man]

I may be a little conservative, of course. A lot of my prep experience and references are for what would be regarded as classic racers now.

This is a car that my grandfather built, W.B.Fowler's 1960 DB4 GT:

Not particularly relevant, but W.B. was a family friend and I happened across this advert earlier when I was twiddling my thumbs. My grandfather built all of his racers and my favourite was a 1933 Aston Martin Le Mans 1.5l

edited to add link:

http://www.racecar.co.uk/carsinternational/roadstock/stock/db4gt.htm

 

[nicksonmsport]

very nice aston! the negative camber shouldnt cause any tyre failures, tbh it will only usually wear when driving in a straight line. the static camber is set so that once on turn the wheel will straighten to give more contact patch and grip in the turns. its a bit of a comprimise as obviously straight ahead driving can suffer as well as turn in etc, but the idea is to get a balence so the car is drivable, but most importantly bloody quick through the corners. i have seen many race and tarmac rally cars running silly amounts of camber. up to 7 degrees in some cases. yes tyres will wear very quickly, so i will likely go with a bit of a comprimise and set the camber at 3 or 4 degrees on track, and if the car goes on the road i will just pull the top mount out to give a more sensible amount of camber to reduce tyre wear.

 

[944 man]

Do you still do it with string? My uncles a pro racer and he still sets his own cars up that way, and so do EMC! []

 

[Neil Haughey]

Kevin has one of those Dunlop type camber gauges. I was going to do something similar but obviously vastly cheaper by finding a nice steel box shaped bar that I could pop my cheapo Sealey castor/camber gauge on to.

 

[nicksonmsport]

got a fair bit done today!

removed the bonnet and made bracket for pull chords on the scuttle.
removed the rear 1/4 windows ready for perspex
totally stripped the door internals to save weight, windows will be replaced with perspex/polycarb
both extinguishers mounted to the floor (tacked in place)
pull cables plumbed in for extinguisher and battery cut off, cables just need to be attached to the shell, this will be done once painted. everything is currently a dry fit, and will be fully welded and installed at a later date

[/IMG]

 

[944 man]

ORIGINAL: Neil Haughey

Kevin has one of those Dunlop type camber gauges. I was going to do something similar but obviously vastly cheaper by finding a nice steel box shaped bar that I could pop my cheapo Sealey castor/camber gauge on to.

He told me that he did it all with string still! He was adamant that he couldnt use anything else. That was at the end of 2008 though, so he has had time to catch up...