BlueBlob wrote:Not going to sort out the quoting, but let me answer a few of the questions.
4. Lowering a car might very well increase the top speed. As will tucking away exhausts that hang out, etc.
very true, flat floor pan is the sh!t, look at the bottom of the GTR, Ferrari's etc
is developing a car's down force worthwhile for drag racing considering the speeds one can get to, to help with traction??
or is mainly for track racing?
A drag car needs the traction most off the line for launch - Unless you have a huge fan somewhere there is not much airflow to create downforce at that stage. But yes - there are lot of drag cars that use aerodynamic downforce effects at high speed. As a matter of fact all the topfuel dragsters run a wing at the back and it's not there just to finish the look of the rail.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10
panic-mechanic wrote:A drag car needs the traction most off the line for launch - Unless you have a huge fan somewhere there is not much airflow to create downforce at that stage. But yes - there are lot of drag cars that use aerodynamic downforce effects at high speed. As a matter of fact all the topfuel dragsters run a wing at the back and it's not there just to finish the look of the rail.
thought as much, but how come very few of the hatch guys look at changing the rear shape of their cars?they all change the nose of the citi golfs, but do nothing to the back end?
20v vs 16v
was told by a certain drag racer that the improved airflow of 20vhead vs 16v head and rev abilty , will give you quicker quarter mile because you are still making power higher up in the rev range than 16v. how true is this? will your drag time be quicker by a large margin by using 20v compared to 16v.or is it a waste of time.
its not how u stand by ur car its how u race ur car
rzr wrote:20v vs 16v
was told by a certain drag racer that the improved airflow of 20vhead vs 16v head and rev abilty , will give you quicker quarter mile because you are still making power higher up in the rev range than 16v. how true is this? will your drag time be quicker by a large margin by using 20v compared to 16v.or is it a waste of time.
Well, 20V can and will make more horsepower than 16V, which will make for a faster drag car. This is a fact.
BUT. Cost is an issue.
The guys in the US almost exclusively use 20V's in drag cars, and most of them make close on 800 to 1000hp. But the cost of those motors will make your eyes water. We're talking like $20k and more.
In my opinion ( and i'm referring to a vw 16v head vs a vw 20v head here ): if u look at the head, the 4 valve arrangement covers more surface area of the head than the 5 valve per cylinder setup.
like : 00
00
leaves just the measely "+" or metal showing in between the valves. ( i think its called quench pads surface area )
whereas the : 000
00
leaves a bit more metal showing around the valves in addition to the "+" of metal of the 4 valve setup.
to me this means that the 4 valves actually provide a greater flow in and out of the head than the 5 valves setup.
and also that the 4 valve setup allows u to go for bigger valves, than the limited design of the 5 valve setup.
yamaha for one have reverted back to the 16v setup on their motors.
even the runx rsi head they develped for toyota trumped their "glorious" 4age 20v head with reverting back to a 16v setup.
surely there must be some science in it??
and also in reference to the s2000 rally cars and their heads having "ALOT" of work...there is only so much u CAN do with a head, not just bigger valves now, and besides port and flow etc: i've seen swirl, port shape, multiple angle valve jobs quench pad work watnot done for honda heads locally for not as much money as some of us are thinking it can cost..
anthony taylor doing his thing for R3k per 16v head..is just one of them..
so for me expensive head jobs having hellelujah tricks worthy of a select few who can afford the arm and a leg to do it are a myth..
my 2cents..
and yes about 20v vs. 16v. somehow i still believe in 16v until scientifically proven otherwise ( not sbjectively like the yanks are using it watnot.... )!myth!
nerville- shot for the link man!
but its LOOOOooong as my....
wys me the bits where they show the flowrate in cfm's or something..not disputing anything man, just reiterating that i'm looking at the science behind it to back it up!
also: I understand the bit about there being no place for the injector on fsi.
thats a no brainer man!
pboy wrote:nerville- shot for the link man!
but its LOOOOooong as my....
wys me the bits where they show the flowrate in cfm's or something..not disputing anything man, just reiterating that i'm looking at the science behind it to back it up!
also: I understand the bit about there being no place for the injector on fsi.
thats a no brainer man!
RIght so let's look at the nitorgen thing. The air you breathe is 80% nitrogen and 20% oxygen. So they pop a new tyre on a rim - what's inside - yup it's already filled with 80% nitrogen and 20% oxygen - now to fill it 100% with nitrogen they actually have to draw a vacuum or purge the air form inside the tyre. SO now basically they just pump it up further with nitrogen thus basically only diluting the already there oxygen by about a third. We tried it on the race cars for a couple of races. Made absolutely no difference to tyre temps or wear and it was an absolute pain to go somwhere to find a nitrogen fill stattion everytime you wanted to change tyre pressure. So IMHO just another clever money making scheme - how would you know there ain't just normal compressed air in that nitrogen cylinder anyway?.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10
panic-mechanic wrote:RIght so let's look at the nitorgen thing. The air you breathe is 80% nitrogen and 20% oxygen. So they pop a new tyre on a rim - what's inside - yup it's already filled with 80% nitrogen and 20% oxygen - now to fill it 100% with nitrogen they actually have to draw a vacuum or purge the air form inside the tyre. SO now basically they just pump it up further with nitrogen thus basically only diluting the already there oxygen by about a third. We tried it on the race cars for a couple of races. Made absolutely no difference to tyre temps or wear and it was an absolute pain to go somwhere to find a nitrogen fill stattion everytime you wanted to change tyre pressure. So IMHO just another clever money making scheme - how would you know there ain't just normal compressed air in that nitrogen cylinder anyway?.
Refering back to the roof spoiler on the back of a citigolf, what about a wing? I take it this will have a negative effect on top speed.... I am now not refering to those massive japanese wings they use on drift cars or show and shine competitions, just a smallish wing. Is there really any downforce being created when going faster with something as such or just pure drag?
I want a bit more grip on the back of my citigolf dragster as the end really gets loose when going faster than 140km/h, ok granted the suspension are farked and these needs to be looked at first, but back to the innitial poin, will a small wing be worthwhile for lets say faster speed stability/handling and at what speed/drag compromise?
