The V8 Owners Forum -

…it handles like a go-kart!

I have been doing some research on suspension setups for my V8 project lately and I’m getting annoyed with people who stiffen or slam their car and proclaim it to ‘handle like a go kart’. While it may be stiff and stuck to the road it DOES NOT handle like a go-kart! If you have ever driven a professional kart (like mine below, called a superkart) then you would realise this.



After any racing event any roadcar I drive shortly afterwards feels totally sloppy. This is due to a number of dynamics being completely different in the way a kart and car handle (which I can vouch for having raced since I was 8, and done my two university dissertations on the handling characteristics of a kart). Firstly, a car is a lot lot heavier than a kart, secondly a car has suspension whereas a kart does not, only the flex in the chassis frame. For a car to have anywhere near the equivalent handling the suspension would have to be solidly mounted to the shell with no form of bushes whatsoever and this my friends, would shake your eyes out. I've driven my kart on some public roads (legally) and let me tell you, even at pedestrian speeds it was a nightmare. Every single ripple and bump really destabalises the thing. Thirdly a kart has very little mass overhanging the front or rear wheels.

Finally, a car uses the body roll during cornering to generate weight transfer (hence grip) to the outside wheels and to enable this, the roll centre is usually fairly high in comparison with a racing car (in fact its possible to set a modern F1 car up to have a negative roll centre meaning its below ground level and can make the car lean in to a corner!). With a kart the roll centre is much lower and as there is no ‘roll’ as such the weight transfer has to be generated by the geometry of the front wheels and their relationship to the rear axle (which is solid) which is why karts run a very high caster angle and KPI (as much as 10º). This is to force the inside rear wheel to lift into a corner, and also lowering the outside front of the kart thereby giving you your weight transfer. The datalogger on my kart shows it can corner at 3-4G...far more than a roadcar.

So in summary, if anyone ever tries to tell you their car handles like that, please correct them

I've driven a race car on Bonneville salt flats with solid mounted axles and believe me it's as bumpy as hell and makes keeping the car in a straight line a job and a half with constant high speed corrections.

A lot of these people who reckon their car handles like a go-kart usually mean they've got it as low and as stiff as possible which is all fine and dandy on a professionally prepped circuit but as soon as they hit a bump half way round a bend on a public road they've lost all semblance off control.

So, yes, I'm with you on this one.

Handling is a term often mis-used though.

generally people use it to describe a car that they think feels rock solid when cornering etc.

More often than not their car is probably an ill handling bastard though. It might grip a bit better, and feel more solid....up to that point where it all goes pear shaped and it crashes.

But to me a car that handles well is one that is very easy to balance, slide, communicates with the driver etc And generally feels very safe to push hard. ie one that wont bite you at every available opportunity.

How it actually grips....really doesnt matter. Although obviously you'd want it to grip well too.

I dont think I'd ever want any car to handle like a go kart. As fast as they are....I dont imagine their handling is actually that good !! more a handful ! always on the edge. But that's racing.

but many are probably right in that it rides like a go kart. ie rock bloody hard and very uncomfortable. So they mistake the term handlies like a go kart...for rides like a go kart lol

Great picture - take me back about 26 years!


Back then I raced in "internationals" or 100cc no clutch and open fuel
Karts back then had no side pods (unless you were running in a kids class)
Chains were visible
We chocked the carb with the palm of our hand at the bottom of the straight to avoid seizing (chain about 3/4 inch from fingers)
We only ran a single rear brake disc (gearbox units ran front and rear with bias bars)
Rear tyres (slicks were 7 1/4inch tread and fronts 4 3/4 from memory

And then someone imported a Swiss Hutlass (Sp) and the whole game changed as that chassis was adjustable on each corner with the use of turnbuckles

Brilliant fun

Please give some specs of your kart

Cheers
Ian

stevieturbo wrote:Handling is a term often mis-used though.

but many are probably right in that it rides like a go kart. ie rock bloody hard and very uncomfortable. So they mistake the term handlies like a go kart...for rides like a go kart lol

A man who knows what he's talking about, i'd go with that.

Ian Anderson wrote:Great picture - take me back about 26 years!


Back then I raced in "internationals" or 100cc no clutch and open fuel
Karts back then had no side pods (unless you were running in a kids class)
Chains were visible
We chocked the carb with the palm of our hand at the bottom of the straight to avoid seizing (chain about 3/4 inch from fingers)
We oonly ran a single rear brake disc (gearbox units rant front and rear with bias bars
Rear tyres (slicks were 7 1/4inch tread and fronts 4 3/4 from memory

And then someone imported a Swiss Hutlass (Sp) and the whole game changed as that chassis was adjustable on each corner with the use of turnbuckles

Brilliant fun

Please give some specs of yout kart

Cheers
Ian

Many thanks Ian. So you used to race something like 100C right? Or ICA? Those were the days. I started out in TKM (remember those? I think they were in their infancy back then) which was great to learn my craft..thgough we didn't need to choke those motors Swiss Hutless are still going strong btw.

Ok mine is a 250cc National (Division 2 ) Superkart. The basic difference between these and Division 1 is that the Div 1 karts use twin cylinder 250 motors whereas Division 2 is restricted to mono-cylinder.

Ok here are some specs:
Top speed: Approx 160mph
0-60: >3.5 seconds
Maximum cornering G: 3g
Maximum braking G: approx 4-5g
Brakes: Front - 6 pot kelgate calipers with 5 inch vented & floating discs
Rear - 4 pot caliper with 6 inch vented & floating disc. Bias adjustable front to rear
Total weight (with driver & ballast): 205kg
Without: approx 135
Engine: Honda CR 250cc reed valve engine. Max power approx 64bhp @ 11,500rpm

Chassis: Anderson Maverick. Adjustable front & rear ride height, adjustable front camber, toe, caster, KPI. Rear diffuser. Adjustable front & rear wings.

Mine handles like its on rails

Cos it only goes in a straight line

Solid mounted rear axel, 11 degrees of castor, suspension mainly through chassis flex, slicks all round, solid rear axel, do you think my new project will handle like a gocart??
Best regards
Mike

My observation is that kiddies who 'make their car handle like a go-kart' have cars that bounce along because the spring / damper time constant is now completely wrong.

Looks ridiculous.

Chris.

Now racking the bran cells

Kart was KT from memory (Kart Technology?????)
Engines 100cc rotary valve single cylinder (higher reving than reeds which "chattered" and we were getting about 18000rpm out of them)
That gives I believe about 25 - 28bhp
Engines one was a Yamaha unit - lower revving but higher trque low down and the other Komet KT88 - a real screamer till it swallowed a nut kicked up from the track seized solid at max revs!
Tyres Blue streaks for "endurance" events or bridgestone until they mandated everyone ran Vegas.
I raced it between 1986 and 1990 and had great fun!
Even made a "slide" exhaust operated by a bike brake handle to adjust the length of it to get better tuning in corners and then high revs on the straight - but got protested out for my troubles!
No clutch so 25mph to max - about 95mph in 2.5 - 3 secs

And this all happened in Zimbabwe!

Ian

I still have an old Deavinsons cart with single cyl 100cc engine, no clutch. Last time we used thought I was going to have heart failure trying to push start the thing. Also have a Rotax Max but not been out in it for a few years.

Dont believe they went as quick as Ian's, that sounds very quick

r2d2hp wrote:I still have an old Deavinsons cart with single cyl 100cc engine, no clutch. Last time we used thought I was going to have heart failure trying to push start the thing. Also have a Rotax Max but not been out in it for a few years.

Dont believe they went as quick as Ian's, that sounds very quick

Hehe, both of mine still have to be push started! Believe it or not your Rotax Max is probably a touch quicker than something like Ians...so get back out in it! I know a great and cheap racing series for them based in the midlands.

As one poster said, yes its all about balance. And with all due respect to the poster "JC." i've seen posting on here, his quote of "Hard front and soft rear, thats the way to make an MGB handle" is totally wrong.

Cars with uprated suspension CAN handle like go karts, I know as I used to race karts and I used to have a Honda Prelude with uprated suspension. The difference is though it was race coilovers, race arms, race everything, even a racing steering rack! There was about £2k work of suspension and handling mods done to it, and no cars could outhandle it, but this was fully set up for track use which is the difference.

I'll agree, lowering / stiffer springs WON'T make it handle like a kart, more responsive yes, but not like a kart.


And hard front / soft rear for handling, no thanks!! Put your foot down to power out a corner, and I don't even want to think how that'll handle with the arse end squatting down like that on a bend!

Crazy wrote: There was about £2k work of suspension and handling mods done to it, and no cars could outhandle it, but this was fully set up for track use which is the difference.

Again what do you mean by handling ?

I'm sure there were plenty of cars that could go faster, and grip better. Handling is purely the drivers perception of how the car feels. It has nothing to do with how fast it actually goes, or whether it grips or not.

Again its all down to perception. With all due respect Crazy, i'm sure it generated a lot of mechanical grip but the major difference between a kart and car is the mass, so a car will never corner as fast as a kart.