Supercar Exhaust Questions

[tbtstt]

Sorry, couple more random Supercar questions for those of you with the knowledge!

My first question applies to a few of the Supercars, but its something I noticed most with the Bakkerud and Doran DS3's (both of which seem to have pretty wide bore exhaust exits). Looking at the cars from behind whilst they were sitting on the line waiting to go, you could see the exhaust "hole" went from black to bright orange in just an second or so.

I understand the cars obviously run a very aggressive anti-lag setup, but enough to light the whole exhaust system up that much, that quickly? I have read a couple of comments on Facebook (so I'm very uncertain of their accuracy!) indicating that the catalytic converter is fitted towards the back of the exhaust system. Is it that which is glowing?

My second question (and perhaps its connected to the above) is that I've noticed that a number of the Supercars (and at least one of the Touring Cars), have mesh and/or supports fitted inside the exhaust pipe just before its exit.

I might be missing something (and apologies for the wasted post if thats the case), but I can't see anything in the regulations stipulating the need for the grill inside the exhaust: so whats the purpose of it? To maintain the shape of the exhaust under high temperature or in the event of an impact? Or for something else?

[dcdesign]

The mesh or other things at the end of the exhaust is purely to tune the noise down...

[BertMk2]

I think it was just the mesh glowing orange - this photo of Liam seems to show that (not the best photo )

[bigted]

ah, can still hear that sweet noise

[tbtstt]

Originally Posted by BertMk2

I think it was just the mesh glowing orange - this photo of Liam seems to show that (not the best photo )

Ah, yeah, that could explain it. I thought it was the whole exhaust system lit up...



...but, now you say that, maybe it is just the grill in the exhaust. The video of Solbergs car testing shows a perfect orange circle in the pipe, so it could be the grill:

http://www.youtube.com/watch?v=vuOOlWfbY6Q

Originally Posted by dcdesign

The mesh or other things at the end of the exhaust is purely to tune the noise down...

Ah, yeah, that would figure!

[chunder]

If you watch any rallying you will notice that a lot of the WRC cars once they have been on stages for a few minutes will have a bright exhaust, especially the old Focus that had a huge tailpipe with a lot of noise baffling in there that glowed very bright always

I would imagine the turbo pressures and anti lag put a lot of pressure on both turbos and exhausts, but not every rallycross car has this feature.

So I would guess it is down to personal exhaust choice, the cars are far too quiet in my opinion yet they are allowed to run these stupid flat shift systems that cut fuel flow and make the car make such a stupidly loud crack on gearchange

Its that kind of noise that travels huge distances and should be banned in my opinion, there is no need for it, plenty of cars run flat shift boxes that don't have that stupid crack ignition cut.

Rallycross especially at somewhere like Lydden so close to houses etc should really do more about this sort thing, the cars are fine, perfectly quiet, too quiet sound wise, but this gear cut thing is well over the top.

[tbtstt]

Originally Posted by chunder

If you watch any rallying you will notice that a lot of the WRC cars once they have been on stages for a few minutes will have a bright exhaust, especially the old Focus that had a huge tailpipe with a lot of noise baffling in there that glowed very bright always

Yeah, I've noticed it on the WRCars before: what caught my eye was how quickly it "lit up". Even though the rallycross cars are only racing short distances (compared to a rally car) I couldn't believe that the ALS would be so aggressive it would cause the exhaust to light up like that.

The lit up mesh would explain what I was seeing though (should have figured that out myself really).

Originally Posted by chunder

I would imagine the turbo pressures and anti lag put a lot of pressure on both turbos and exhausts, but not every rallycross car has this feature.

I know a few road cars that have ALS (obviously in a much milder form!) and the turbo and headers suffer the worst. I believe that the ALS setup in the very expensive rallycross cars is a bit more sophisticated, but I assume its the same engine components that are going to suffer.

Originally Posted by chunder

Its that kind of noise that travels huge distances and should be banned in my opinion, there is no need for it, plenty of cars run flat shift boxes that don't have that stupid crack ignition cut.

Ah. I best keep quiet then, as I quite like the pops and cracks on gearchanges...

...do agree that a lot of the engines lack any sort of note though. Godfreys Fiesta springs to mind as the worst offender at the European Rallycross; didn't sound like it was on half the time!

[rs 200]

The noise thing should be looked at the de-tuned supercars are way to quiet ,you can hear the s1600 a mile off revving to 10k ,how come they can be that loud but Sc can't .This noise thing gets people hooked on these cars ,it did for me standing at the bottom of paddock hill at the s's then hear the roar of pure power going up the hill ,many people I know got hooked on the noise of the SC back then .as said do we need als launch ,the answer is no get rid of it make the drivers work but give us back some engine noise from the exhaust .

[chunder]

Agreed RS

I remember the sign of a well set up car was two changes on the Hill, remember Rennison once banging two changes in there, two quick flashes from the wastegate and a surge of power both times, als remember watching Rasmushaugen munching into a lead Alamaki had on him up there without even changing, that car was super powerful.

I think a lot of eh noise and power deal is based around the engines we use now, back then they were unlimited, limited only by money and transmissions, now they produce huge torque, Solbergs in particular was so low revving, it is still nice to listen to but could with being louder.

I just don't think we need these silly cracks on gearchange, I remember Mark Watson getting told off about it a few years ago but on Sunday a lot of cars had it, remarkably most of the quicker ones didn't! Fousts is very quiet!

[Mad Mark Watson]

Originally Posted by chunder

Agreed RS

I remember the sign of a well set up car was two changes on the Hill, remember Rennison once banging two changes in there, two quick flashes from the wastegate and a surge of power both times, als remember watching Rasmushaugen munching into a lead Alamaki had on him up there without even changing, that car was super powerful.

I think a lot of eh noise and power deal is based around the engines we use now, back then they were unlimited, limited only by money and transmissions, now they produce huge torque, Solbergs in particular was so low revving, it is still nice to listen to but could with being louder.

I just don't think we need these silly cracks on gearchange, I remember Mark Watson getting told off about it a few years ago but on Sunday a lot of cars had it, remarkably most of the quicker ones didn't! Fousts is very quiet!

i actually liked driving with it as i felt certain my gear had changed and was a flat change not every driver can do
there are two methods you take the fuel out on flat change or inginition if ignition is out then the excess fuel is exploded in the exhaust and so the bang and usual flame now you take fuel out with means there momentary break while we flat change we have changed to this we also have an s shaped exhuast and pipe at rear faces down which means our nois in 94 db saves getting told off and lock wiring a can of fosters if your tail pipe

[rs 200]

As far as these high torque 6k revving engines to me are a load of old poo ,just like the wrc things ,did you hear them off the line 5th gear in 200meters .
should have 4 speed box no als no launch ,bring on the drivers
as much as I love als launch etc without these we would not need joker laps ,bit of lag in the corners wrong gear we have what we did overtaking ,you can get 500bhp for 10k or 500bhp with loads of torque 50k, money to be saved and better watching.

[tbtstt]

Apologies for the thread bump, but I meant to post in here again sooner.

A couple of weeks back I was at the BHP Show (at Lydden Hill). The Doran team had all their toys out and there were a few members of the team. Happened to getting chatting to one of them who turned out to be one of the team mechanics, so I thought I'd ask the question about the exhaust glow: its not that mesh glowing, its the catalytic converter!

[rs 200]

That a joke having a CAT on rallycross rally cars as all they do is bellow out unburnt fuel black smoke . I bet it makes no difference to the emissions at all .

[Distracted]

http://instagram.com/p/ZoR8y6C8mQ/

[Schanche1965]

Even back in 1995 we had to run catalytic converters in GpN Division 1 cars, Cronge Nordstedt (Anders Nordstedt`s brother - the FIA scrutineer) used to regularly check to ensure we were not running empty cats by pointing a laser temp gun before and after the cat after heats and finals, if the car has a working cat the temperature after the cat is higher than the entry temp.

[FIRE]

Originally Posted by rs 200

That a joke having a CAT on rallycross rally cars as all they do is bellow out unburnt fuel black smoke . I bet it makes no difference to the emissions at all .

It's demanded by FIA just for the "green" image?