Putting the power down

[Dr Forinor 0]

Right, I know a lot of people have shoved a s/c on their VRs, I was just wondering, how does it cope with it being a FWD car and all that power? How much power do you typically put out with a supercharged VR? How does that affect torque-steer and what about all this "max power 220-240bhp for fwd malarky" stuff?

[gibber 0]

I realy struggle with a standard box and dif!

[Dr Forinor 0]

Struggle how? I'm a little stupid so you have to explain these kinda things to me.... lol

[h100vw 0]

What he means is that the tyres can't cope. The std differential allows the wheels to spin independantly which will stop the car from moving at all.

 

Imagine parking with one wheel on ice and the other on the road. When you set off, all the power will be transmitted to the wheel that spins on the ice and the car will barely be able to move.

 

This is why setting off on slippery surfaces is easier in a higher gear, as it is harder for the enignes torque to overcome the grip.

 

The cure is a limited slip differential. Basically, when the diff senses any slip it locks up so that both wheels are receiving the same amount of power.

 

I am sure in gibbers case, things would be better if he got rid of his divers boot. :mrgreen:

 

Gavin

[potatonet 0]

gavin = a funny man hahahah :lol: :lol: :lol:

[Dr Forinor 0]

So I am assuming that most people with a supercharger fitted to their VR will have that problem unless they make other adjustments?

 

Has anyone gone to the lengths to make sure that there is no weak link?

[h100vw 0]

Yeah, restraint works wonders. Don't be surprised that your car uses more tyres than petrol, if you have a a wooden leg and cannot modulate the throttle well enough to stop the wheels spinning. :mrgreen:

 

Having an LSD fitted will cost nearly as much as the SC kit.

 

I have been in a SC VR6 Golf, my mate was driving and the acceleration was tremendous but I don't recall him lighting up the tyres, he is a pretty reasonable driver mind.

 

Gavin

[Henny 0]

I have an LSD in my G60's box 'cos otherwise I'd never get any traction... :|

 

Even so, I can still spin both wheels (as I did on the M56 today :oops: ) hitting third hard when it's wet (and yes, my tyres are in good condition!) just purely down to the torque...

 

Without the LSD (or more correctly ATB diff - Automatic Torque Biasing -IE it shoves the power to the wheel with the most grip) I'd be spinning one wheel in every gear and would never get anywhere...

 

When I set up my engine/box project (originally for J-DUB) I tried my hardest to ensure that there's only one weak link, that being the inner CV joints... The theory being that if there is a slightly weak link then that's the bit which will take all the abuse and eventually give up rather than stressing ALL parts until something random lets go, I'd rather make sure that the bit that's most likely to let go is cheap to replace and not likely to make too much mess if it ever does let go! :lol: Even so, the standard G60 inner CV should be good for the 250ish BHP the engine's making, so it's not exactly a weak link as such, just the one I know is most likely to be a point of failure in the future... 8)

 

I'd imagine the problem is even more pronounced with a VR6S/C as the torque it's making should be somewhat more than my 1940cc 4 pot...

 

LSD, fitting and gearbox rebuild cost me £1024 from Vince at Stealth nearly 2 years ago but I'd already removed it from the car and refitted it myself...

[Dr Forinor 0]

Thanks for the replies everyone, you guys are great, this forum is really a good place to come to if you wanna learn :)

[Lippy 0]

and spend money!!

[samm_cvr6 0]

I have often wondered the same thing about you guys with charged VR's with out wanting to get my pipe n slippers out.

Wasn't all this 225bhp=max bhp for fwd quoted by that Saab dude in like the 1970's anyway? now we have, tc, and lsd to help and hot hactches are coming with 18/19 alloys so don't really see the problem too much. Haven't heard too many complaints from some guys with 280+bhp Leons any way.

[H8RRA 0]

its as much technique as anything - i have an lsd and 6 speed box to put in but at the mo with a stg2 kit I can still get away very well - obviously i could hoof it and just stay stationary whilst the wheels spin but you can do that in most front whee drive cars.

 

Are you thinking of charging, Dr?

[Dr Forinor 0]

Oh no, I want to keep this Storm standard, retain it's original value, I'm funny like that so don't make fun :-P

 

But I was just curious, and always lookin to learn :)

 

Hopefully when I have the money I may think of a project car :wink:

[Henny 0]

Dr Forinor, cool attitude... 8)

 

They had LSDs (all be it mainly clutch/plate style ones) and the like back in the 50s, never mind when that SAAB bloke wrote the 250Bhp max for FWD cars thing, however tyre and suspension technology has taken some pretty major advances since then which makes 250+ somewhat more managable...

 

I don't have many problems with getting the power of my G60 down onto the tarmac as long as I drive it with my brain switched on... the wheelspin into 3rd on the M56 this morning was almost certainly more about me having not driven her for 3 weeks and having been used to a 1.6 Corrola Auto hire car than serious problems with grip... :oops: :lol:

[Dr Forinor 0]

Dr Forinor, cool attitude... 8)

 

Thank you :thumbleft:

[dinkus 10]

For a more practical feeling of what happens, have you ever tried giving it some welly accelerating out of a slow bend when the car is revving quite highly and had the steering wheel fight you?

 

The more torque you have, the easier it is to do that...

[potatonet 0]

henny, I bet that pulled a bit more than the 1.6 Corrola rental, btw you might want to check this out if you are in the mood for fixing your weak link...

http://www.driveshaftshop.com/item9521.ctlg

a bit pricey at 1000 US... I was gonna but then realized that Im only going 16Vg60 so I find it useless.

[Henny 0]

ummm... nice shaft....

 

[insert pun here]

[GazzaG60 0]

lets get one thing straight. HP dont mean shit. its torque that is the important factor and how low it comes in. after all HP is a calculated figure based on torque.

 

I have the problem that henny has with wheelspin even on the 17's. FWD needs an engine that develops the power slightly higher than a G60 for optimum. look at the hondas. they make piss poor torque but will drag it out for 9k or so. add a turbo and its an almost unbeatable combo and with traction to boot

[CoxyLaad 0]

thing is, if you have to feather the throttle to stop the wheels spinning then you are not using all the power available and therefore its not needed? (unless of course you hobby is doing flat out top speed runs everywhere you go?

 

For me the enjoyment is powering through corners, not waiting until I am going fast enough to not spin the wheels.

[Henny 0]

Mine tends to break loose around 3.5K to 4K rpm which isn't exactly low down in the rev range (seeing as it's making 150+ LBFt from 1250rpm!)

This is where peak torque starts to be produced from my engine (all the way upto around 5.5K!) however, it only ever does it if I hit full throttle while turning hard in the wet... a combination that's not very clever in any FWD car... :roll: :lol:

 

I've never feathered the throttle on my car (probably explains my tyre costs! :oops: :lol: ). On a straight (or even exiting a corner) I can happily just shove my foot into the carpet and let the LSD deal with getting the forwards thing to happen!