Dry Lakes Racers Australia

Ok we have 2 trains of thought happening here .....1.tuned length headers and there benifits & 2.taking the exhaust and pumping it behind the vehicle......interesting .... one (tuned length headers) is proven to increase the performance of an engine (verified data)....two in theory at least dumping the exhaust at the rear may have benifits??? does anyone have verifiable numbers of the net benifit/gain to drag reduction. so I ask is it worth the power loss from a tuned header setup to extend the exhaust system to the rear of the car/bike ? or for a turbo, does running a long exhaust system to the back have more benifits than the extra back pressure created in doing so ...I will ignore for the present the extra drawbacks of getting an exhaust pipe back there ......is it just another fad or is there real proof with repeatable data that the benifits out weigh the costs ?
Gary #282

Have a read of the stuff on the link I posted on the previous page and make your own decisions Gary.......speed costs.

Ive seen a video of a top fuel rail blowing off a set of headers and going into a barrel roll. Apparently the thrust from the exhaust blew the car over.

Thanks Chris - that is what I was hoping you would say.

Cheers
jon

Dr Goggles wrote:

ben james wrote:1./ The exhaust gases are cooling rapidly, that means they are shrinking, that is an excellent way to "de-energize" the wake , it works kind of like a dampener. DAMPER

.....back to the rear exiting exhaust ... is there really enough exhaust mass or volume to make any difference at all .... considering the overall amount of air being displaced ??? I personally believe it will only have an effect on streamliners and then only a small net gain ... but I could be wrong.
I think some 4 cylinder top fuel motorcycle teams have some data about exhaust effect.
Ben

I think you're trying to have your unleavened bread and eat it too Benny,.......get a Webster's up ya.

there ya go with your big words again,
i don't know what unleavened means,
but i'm gunna look it up & do a real witty comeback i am.

Ben , hurry up with the unleavened explaination !! We're getting " exhausted" waiting to find out what it means,

OK Bob, turns out Benny has an ongoing argument with a yank he works with about damper/dampener....if you ask me damper is like bread, without yeast.....bread without yeast is said to be "unleavened"...it doesn't rise.


Now. Did anyone read any of the stuff that Superford317 posted on the landracing link that I posted?.......You door car guys might have noticed that Michael leFevers posted a pick of their Firebird that was the 300mph car......

It isn't something you can condense into a one word answer this stuff. As Chris mentioned he's had time to think, and has reconsidered a few lomg held ideas. It never hurts to go back to basics and think about what we are trying to do. I'm trying to do it now..............

Quote" Now. Did anyone read any of the stuff that Superford317 posted on the landracing link that I posted?......."" end quote ....... sure did, all very interesting and informative BUT!!! ........conclusion WTF has any of that realistically got to do with backyard builders......I will watch closely as those with racing budgets the size of the US debt implement any of it into a practical solution then copy the stuff that works ......in the meantime I will continue building the born again fleabay special ....racing costs thank acura for China.

Racing does cost.

Components cost money.
Innovation, design, fit and finish cost research, care factor and attention to detail.

If scratch building a component in this discussion an exhaust the $ cost between a set of zoomies and a tuned set of tuned length pipes (non dyno tested) exiting where you think you may pick up some advantage is negligible in the total build cost.

YOMV
jon

Aerodynamics are free, and they don't wear out or break.

Vortex Generators , Nebulus therom liner is long and tiny built by an expert and i think it is about as high as my knees . It has and uses Vortex Generators at the back to further enhance the air leaving at the back . I dont think that i have seen votex generators on a vehicle at our lake . There was some on a vehicle at tailem bend but they arn t the real deal .

I stumbled across this a while back after watching a show on TV about the Spitfire, and how they gained thrust from heat generated by the engine.

http://warbirdsforum.com/showthread.php?t=5515

Dr Goggles wrote:Aerodynamics are free, and they don't wear out or break.

You're not a bike guy, are you
G

grumm441 wrote:

Dr Goggles wrote:Aerodynamics are free, and they don't wear out or break.

You're not a bike guy, are you
G

Why? Cos he can spel Airodinamiks propa and uses punchyouassian?

grumm441 wrote:

Dr Goggles wrote:Aerodynamics are free, and they don't wear out or break.

You're not a bike guy, are you
G

guy? isn't your spell check working properly?