No weight at the back?

This is a question I've been asking myself recently - now that I've essentially stripped the entire rear half of the car the weight distribution (i.e. engine, seats and me) is massively biased to the front. I can certainly feel this on track, particularly in the wet - there's a lot of movement from the rear of the car under braking and during any mid-corner throttle adjustments.

I fitted my BC coilovers exactly as they arrived from the factory, but having done a bit of reading around and having read through this guide https://turborenault.co.uk/mk2-mega...-settings-and-ride-height-information.t45301/ I will be raising the rear ride height, which ought to help balance out the front:rear weight bias a little (obviously getting proper corner weighting done would be the ideal solution, I'll be getting this done once I've finished stripping\adding parts to the car).

The other thing that's been on my list for ages is to relocate the battery to the spare wheel well - again it's only a relatively small amount of weight to move, but it seems like a sensible idea.

Beyond that it's just going to be a case of removing as much weight as possible from the front of the car to balance out the relatively large weight reductions made at the rear (i.e. rear seats, boot floor, spare wheel were all pretty heavy).

 

To equalise the balance you'll want to decrease the rear ride height, not increase it. If the weight balance is say 20/80 at the moment decreasing the rear and even increasing the front would make it say 30/70. Corner-weighting won’t ever magically make it 50/50 or anywhere near it but it will help a touch and what it will do is balance the weight better across the axles, i.e. front right and front left, rear right and rear left. You can have it corner-weighted with you (or a similar weight) in the driver’s seat so it’s perfect with just you in the car, but would be slightly out if ever you had a passenger with you.

 

^^what he said^^

 

Yeah assumed this is what corner weighting is for.

Altho no good for semi hardcore peeps like me not on coils

 

Just to be clear you can't move static weight from the front to the rear by corner weighting. You can only achieve significant F/R weight distribution changes by shifting mass or by adding ballast. You can alter cross axle distributions in mass.

 

Weight balance is far more important than weight.

 

yep. cross weight reading of 50 is optimum over overall weight

 

I think Mike has answered the original question perfectly.


So unless the weight of removing the spare-wheel etc. is going to be replaced with a battery or/and swirl-pot or dry-sump system etc. etc. then it’s probably best left in.

 

Nope, because removing static weight can other advantages other than just trying to achieve a good front/rear weight distribution. You have to brake, accelerate and throw mass around bends.

 

Had my car corner weighted recently so it's 50/50 with a passenger

Front/rear is indeed a bit naff - 62/38 biased to the front

 

Thats quite good I think.

 

For a car on track the last thing you ever want to do is add extra unnecessary static weight to make the % ratios look good.

 

I guess out of the two its best to have more weight over the rear on a RWD car 70/30(911/Elise etc.) than over the front on a FWD car 30/70. The drivers of BTCC cars are virtually sitting in the back seats anyway.

 

New Business Opportunity..... Trackday Rent a Passenger for Improved Lap Times

 

It's all in the set-up. While an imperfect weight distribution is a compromise, the negative effects can be tuned out to a large degree with good geometry and spring/damper rates. That's where the problem lies with most aftermarket suspension. It's another compromise designed to suit certain conditions and built to a budget.

Lots of FWD race/rally cars out there with incredibly light rear ends. They just have the budget to optimise the set-up to reduce the negative effects.

 

Yep, the set up is such a major player.

The carbon bonnet brigade will often just buy suspension based on peer group pressure 'you need BC, no KW, no AST mate, who's got Nitron's? they look really good' but you very rarely see any detail about how they are set up, weighted and fine tuned for purpose. Just crank the ride heights so it looks good, fills the arches, pop a KW sticker in the window.

 

The carbon bonnet brigade, as Aerofoil put it, whats wrong with that?. Its individual choice. If someone chooses to kit out their car, with every Halfords parts available, and go no further than Tesco, that fine by me. I do not think its right to sneer at other peoples choices.

 

Sure, freedom of choice and all that. Equally, freedom to have an input.

Blowing a few grand on suspension that is never correctly set up, researched and more importantly defined as really necessary for someone's objectives is a waste. Plenty of fellas telling you get AST etc but not many asking why do you want them, what are you looking to achieve.

 

That's modified cars generally though. Most modifications aren't nearly as good as they could be thanks to budget and other compromises. That even goes on right at the very top of Motorsport based on my experience. Everything is a compromise between budget, timescale, parts availability, manufacturing etc etc.

None of us are talented enough to notice the difference in reality. So long as as people are happy with what they do, it isn't worth worrying about.

 

Yhe green eyed monster,keep saving your paper round money duck

 

Most people will instantly notice the difference in key performance mods such as suspension.

Whether they ever fully utilise the extra suspension capability, ever get it set up, or are better off putting the money elsewhere is the point. Sadly the world of social media is very quick to push the flash kit or much more importantly, 'I'm not really interested in what you want it for.......just buy what I have'. Herd instinct, lots of nice images of Gucci kit. Don't be left out.

 

be nice for you to put all the advice into practice when you get a car

 

duck.........lol

 

Bloody spell check........lol

 

Aerofoil, i take it round your neck of the woods, there are a lot of the `carbon bonnet brigade` with KW stickered windows & no sense on how to drive a car properly?

 

Yep, but not all have a KW sticker.

 

We tend to get a lot of `Poundland` stickers in car windows, probably reflects the class of `chav` round here.

 

The neck of the woods in question here is the territory frequently occupied by the Trackday warrior. A fertile patch of paddock bling and associated under-utilised modifications.

 

A territory you would love to visit once you get a car and life......lol

 

Does it matter that much though? Some people enjoy the experience of modifying their car every bit as much as driving it. It doesn't really matter whether it's utilised or not. If you keep worrying so much about what other people do, you'll end up having a heart attack...

 

He just fishing for bites, has a long history of it, got absolutely destroyed on Facebook so is trying his luck on here again, sad but true

 

Ok back on topic. So for those who have stripped out the boot and the rear passenger seats, how did you compensate to maintain (to a point) the F/R balance of the car. I can only think of battery relocate

 

You can't unless put bag concrete in trunk. Lower tyre pressure to help with traction and forget any aero wing assistants

 

Oh and as already said corner weight and lower rear ride height

 

On the contrary I have heard that FWD high end race teams use aero on the rear to get some rear download at high speed, to offset a very pointy low speed setup where the light back end is allowed to be very mobile to counter low speed understeer. Thus the aero is then required to get a nice balance at speed where the car would otherwise have horribly loose handling. This would be real aero of course not bolt on tat for visual effect.

 

Yes you are correct if your talking full on race car which has undergone wind tunnel tests and relevant wings attach, do you think we're talking about that type of vehicle here ?

 

Not at all bobsan, not impossible though as Porsche, Lotus and Honda have put real aero on cars on recently. Club racing outfit I used to knock about with it tried and created so much drag they dropped 15 mph on the straights! Clearly its quite a black art to do well, I know how to calculate required damper low and high speed bump and rebound for example but wouldn't touch aero, a mate and ex work colleague did his PhD at Cranfield into Computational Fluid Dynamics for just this sort of thing. Made my brain hurt far too much.