15 replies to this topic

[R3D VX]

Dear all, have now finished modding for the time being. The car now boasts Spax suspension, K&N induction, pre-cat removal, Vx sports exhaust and now finally the stage whatever it is ecu tune and platinum?? plugs from Regal. First impressions were of a much smoother engine, you really notice the higher rev limit (which is soft when hit!) and you don't believe your eyes when you look at the clocks! I did a well driven piece of road that my Supra Twin Turbo loved. On the straight part the STT used to reach 135mph, I coaxed 120mph from the VX! This is only a short straight!! The supra had 400hp! Not bad i think! Just gotta save for the inlet manifold now, Anyway, if you are thinkin of doing the Regal thing I can really recommend the software. The car is with Vauxhall today for its annual service so I am twiddlin my thumbs (yes i told them not to touch the plugs and filter!) Take care all, Mike

[minime]

you just wait until you have the inlet manifold! then the car will howl with pleasure!

[PaulCP]

you just wait until you have the inlet manifold!

then the car will howl with pleasure!

Steve

On this subject how much did the inlet manifold increase the in-cabin noise levels over the full exhaust, K&N & re-map.

I am now contemplating the next stage but don't really want to increase the noise much more.

Paul

[TheRockstar]

Mike, If you don't mind me asking, how much was the whole package, and how long did it take?.. I'm sure I'm going to go for the Vauxhall Sports exhaust, K&N and the Pre-cat removed (which I'm banking on costing around £800 all in) but how much difference did the regal re-map make for the extra money (and how much)... Ta Nick

[VEX]

Rockstar, Thats basically the same mods I am going to do. However I'll go for the Regal exhaust as it is a bit quieter and therefore more likley to pass the track day requirements. Mikes R3D VX is luuerly and loud, but as he say it does make its presents felt! The cost of the regal Stage 2 mod is about £410 notes with the fitting costing £98 odd. Stage2 is Plugs, Air Filter and Remap. Nice little birthday present to me I think! Cw

[TheRockstar]

Thanks Chris, So how much is the Regal exhuast + fitting?... My only concern with fitting the regal exhaust is the crash worthiness, as the Vauxhall exhaust is designed to add to the crumple zone at the rear. Little concerned that the regal one is designed purely for performance, and a rear end shunt may therefore cause more problems...... Nick

[Thorney]

My only concern with fitting the regal exhaust is the crash worthiness, as the Vauxhall exhaust is designed to add to the crumple zone at the rear. Little concerned that the regal one is designed purely for performance, and a rear end shunt may therefore cause more problems......

Nick

Well bugger me senseless....I didn't know that.

[Dave T-S]

Thorney I for one will decline the offer, ta, but it's correct re the exhaust

[minime]

i think you will find that the vauxhall sports exhaust would have problems with a rear shunt aswell if that is the case....... as far as i am concerned all exhausts will act as a crumple zone......

[PaulCP]

Thorney
I for one will decline the offer, ta, but it's correct re the exhaust

Is it really correct or just a marketing ploy??

The standard exhaust in my garage taken off my car looks no different in basic design to the Regal one now fitted.. There is however a weight difference so this may bear some relation to impact sustainability.

[TheRockstar]

Car crumple zones are designed to collapse in a pre-determined way, i.e to maximize the reduction in force by absorbing the energy in a particluar way. A good example is this - take a piece of paper and fold it in half, rest it on the desk in a ^ shape, then flatten it and feel how little energy it absorbs. Now fold the piece of paper in half the other way (i.e. make it into a little wall with a 90degree bend in it) and then try again. It takes a lot mor force to flatten it. Crush cans, and side protection sills are all designed with careful attention to creases, folds and baffles within them. I'm assuming the vauxhall exhaust is the same, they will have run an FE model of it during design to maximize the energy it absorbs. It may 'look' the same in terms of physical size and rough shape as the Regal one, but it may not have the same absorbtion capabilities...... Nick

[VEX]

This is why the Sports Exhaust from Vauxhall is stamped with 'Not for Road Use' The weight difference is massive and some of that is the 'crumple zoniness' of the thing Hey, nice new word! Zoniness! Cw

[Thorney]

A good example is this - take a piece of paper and fold it in half, rest it on the desk in a ^ shape, then flatten it and feel how little energy it absorbs. Now fold the piece of paper in half the other way (i.e. make it into a little wall with a 90degree bend in it) and then try again. It takes a lot mor force to flatten it.

OK, you're scaring me now

[TheRockstar]

Maybe that wasnt such a good example then.

[garyk220]

Bearing in mind you've got the engine/gearbox and fuel tank between yourself and the exhaust back box, it's all academic really. The only thing the standard exhaust crumple zone will protect is the engine and rear subframe (at very low speed impacts). If something hits you hard enough to punch the engine through the fuel tank and chassis, the exhaust crumple zone is not going to make much difference IMO. So in my view, while it may reduce damage in a low speed impact, it will make hee-haw difference when you really need it

[Dave T-S]

This is why the Sports Exhaust from Vauxhall is stamped with 'Not for Road Use'

It's a nice thought, but sadly I believe the reason for this is much more boring. As part of the Type Approval process, without which a car cannot be sold legally in the EU, vehicles have to pass a drive by noise test, which the Vauxhall sports exhaust probably wouldn't pass - these are the E11 (11 being the UK designation) marks you will see all over your cars (unless you bought a non EU import ).

This only applies to OEM parts that the car is homologated with, but technically if a dealer fitted the exhaust to a brand new unregistered car it would fall foul of the regulations.

Subaru and Prodrive for example get round this by only fitting the Performance Pack and other enhancements to cars after they are registered - the Type Approval process doesn't then apply to secondhand parts in the same way.

Re the exhaust being part of the crumple zone, there is no legal or Type Approval requirement for crash testing standards yet as such - although there are certain basic safety standards - but Max Mosley is constantly pushing the Euro NCAP (New Car Assessment Program) test and this will, probably, eventually become part of law/the Type Approval process.

At the moment the tests cover head on, side, pole and pedestrian safety, but rear impact is not considered to be that important.

In a head on crash there is a massive amount of kinetic energy that has to be dissipated, and this can only be absorbed through the structure of the cars (or their occupants). In a rear end accident the shock loadings are much less, in relative terms, because the car that is hit is normally able to lose some of the kinetic energy by bouncing forwards.

Sir Isaac Newton's third law of physics - "every action has an equal and opposite reaction"

Edited by Dave T-S, 17 April 2003 - 07:58 AM.