When I got home from work tonight, I took the bumper off and partially reversed the big mouth on my Fabia. Specifically, I replaced the chopped crash bar with one which might actually do something in a crash. Once I'd got everything back together though, I realised it blocked off more of the FMIC than I thought it would. I'm guessing the only time this would really affect me is dyno runs or long track days, it won't make any difference for fast road use, will it?

Just do what i've just done on my octy and get a couple of lenghs of flat bar steel and find a friend whos handy with a welder and weld them onto it to help strength it back up again

http://i16.photobucket.com/albums/b34/Volvomeg/Skoda%20pics/2012-02-21095552.jpg

http://i16.photobucket.com/albums/b34/Volvomeg/Skoda%20pics/2012-02-21095546.jpg

http://i16.photobucket.com/albums/b34/Volvomeg/Skoda%20pics/2012-02-21095524.jpg

Hmm, whats the difference between one welding steel bars to re-enforce the cut up crash bar and welding a custom bull bar to the chassis? :think: Not sure I'd want to meet the front end of any custom weld crash bar jobby (fact, not sure I'd want to meet any front end with force lol, but you get my point).

Hmm, whats the difference between one welding steel bars to re-enforce the cut up crash bar and welding a custom bull bar to the chassis? :think: Not sure I'd want to meet the front end of any custom weld crash bar jobby (fact, not sure I'd want to meet any front end with force lol, but you get my point).

Are you saying you wouldn't trust a welded up crash bar for strength, or that it would infact be too strong once welded and not break/crumple in a crash?

Stiff! Hence bull bars ref. aren't crash bars designed to flex and take the impact of a crash? Don't know how you'd stand from an insurance claim if an assessor finds a cut up crash bar!?

I've only put the strength back into it where i've cut it out and having been in a front end smash i want to keep some strength up front

Any power loss dependant on the spec of your car maybe?

Someone on here with stage two (?) did two dyno's - one with the wide mouth and one without. He said he lost 7-8bhp after reversing the wide mouth.

Cant remember who it was though. :wonder:

Well if that's the only difference it made on a dyno, there'll be just about sod all difference on the road really. I think I feel better with a few bhp less but a crash bar that'll provide some chassis strength if the worst comes to the worst. There's always the option of drilling holes in it for airflow without just removing half of it, and it'll still be stronger than the old one

I've got circular holes in mine dude. Will try find a pic

Just about see em in this one

Yeah, I saw from some of the other threads, Jase drilled those while he still had the car so there's a few of his old pics floating around as well. Trouble is drilling will still make it weaker as (IMO, and if my GCSE science is right ) a lot of the strength that the crash bar has is due to it being ribbed, similar to the way folding a piece of paper into a concertina makes it capable of holding much greater weights than a flat piece of paper. So now I've put a complete bar on, ideally I don't want to modify it at all and just keep it complete as it was designed, as this is going to offer the best crash protection. Sounds like I should be able to do that on the road with no issues, but it might affect dyno results as my car will heatsoak earlier than it would do otherwise.

good work mate, are you completely returning it to stock?

Me? No. I've just never really been convinced that such an extreme modification to a crash bar is "safe", even though it got through its last MOT like that, so I saw a replacement bar from a salvage company on eBay a couple of months ago and picked that up. I'm not reversing the plastic bumper and putting the numberplate back in or anything like that, as that's just cosmetic, the part I was after was just trying to ensure my own safety in an accident. I know many people have chopped their crash bars in various ways, but I'm just not convinced that an extreme modification such as the one on mine was going to be very safe in a frontal impact. I can live with losing a few bhp on a dyno if it's going to increase my chances of walking away from an accident on the road

the question then is do you prefer the looks of a big mouth bumper or stock looking bumper?

i am not knocking putting the crash bar back on because i wouldnt ever remove or modify mine either but if the crash bar is there then that part of the bumper you remove to convert it to big mouth may as well be there as you are not getting any more air flow to the front end now the bar is in place so to me you may as well have the nice looking stock vRS bumper back.

i personally find the big mouth conv a bit barry boy - altho it serves a purpose when teamed with a crash bar removal/modifcation.

Yep, but given that a new bumper is ~£200 from dealers (or say £100 second hand), plus painting, plus blending into other panels, plus if I'm having paintwork done I should get the bonnet done to cover stonechips, plus etc etc etc, I don't have the money for it at the moment. Long term, I might think about it, but for now I'm simply addressing the safety aspect, particularly with my MOT due tomorrow and this being the first time it'll be going to my tester.

You could just put the reg plate back in the correct position to cover a bit of the bigmouth. It'll only cover where the crash bar is.

Yeah, I'd have to get a new front plate made up as mine's fitted with an offset square plate. I think it might actually look worse if I did that though, so I'll leave it for now, and just think about replacing the whole bumper in the long term. Depending on what happens over summer I may drill some holes in this bar after all, I can't see there being much difference on the road having the FMIC covered but this isn't exactly the right weather for judging FMIC efficiency on the bum dyno cos it's so cold and wet!

I think you'll only see a noticably difference in sustained hard driving.

If you are just pottering about and doing the odd sprint there is probably not a lot of difference in performance.

Do a track day in the summer and after a lap or two it'd probably be quite noticable though.

I run my plate up front as I try to keep the car looking as standard as possible.

better pic

think i went with 40mm holes

Do you have to cut anything on the bumper to make it wide mouth

Do you have to cut anything on the bumper to make it wide mouth