mart360

Matty01

the big bang theory was fine for 2 strokes as they have explosive power delivery vs sharp acceleration curves

Also the power to weight ratio was far less than the average scoob


The four stroke engine enables a smoother delivery of power without the peakiness and snappy power on power off which if my memory serves me correctly was the bane of the big bang theory


if you look at the dukes of today, they use a four stroke cycle with a reduced stroke/ cylinder angle to give the power of the big bang with the smoothness of the fourstroke.

the bottom line is really the exhaust set up,

if you need to compare look at a standard inline ford with a v configuration four into one exhaust manifold, listen to the exhaust note..

then look at a saab 900 turbo with its four into one L branched exhaust manifold, listen to the exaust note

then do the same with the scoob with its two into one manifolds
X2

hope this helps

mart

Hoppy

Folks, listen to Greasemonkey. He knows how to burble

It's all in the pipes, not the boxer configeration. I have equal-ish length headers and it doesn't sounds like a Scooby at all but it has more top-end power.

Many big power Scoobs have equal-length pipes which are expensive to make and a very tight fit to clear the electrics around the engine bay and give decent ground clearance.

Nasty things IMHO. I want my stock pipes back on, but need a re-map first.

Richard.

PS Edited to add, Mart, "big-bang" two-stroke GP bikes were all about tyres, and nothing to do with smooth power delivery; quite the reverse. They increased the time between each power pulse, giving the tyre a chance to regain grip. Then tyre technology got better, and the top riders reverted to the original "screamer" motors.

[Edited by Hoppy - 1/30/2004 12:57:38 AM]

mart360

hoppy

re the big bang

i stand corrected

Mart

richrussell

Hoppy's right - a Renault 5 GT Turbo makes an uneven burble (not as deep as the Scooby though) - again due to having uneven length exhaust headers.

That's an inline 4 cylinder engine, with a cast iron exhaust manifold leading to a turbo at one end. So the gases from cylinder 4 have to travel a fair bit further than the gases from cylinder 1 (next to the turbo).

People have fitted equal length manifolds (a very tight squeeze in a Renault 5 engine bay ) and the engine sounds very different.

Rich.

Northern Nick

iTrader: (1)

I was going to mention the R5 Turbo, they sound lurvely

It is all in the headers,

What is strange is hearing a scoob with equal length headers, you dont twig striaght away but when you do, its wierd

Northern Nick

iTrader: (1)

Just realised I was looking at an archive.

Sorry

Mr Footlong

iTrader: (7)

Don't feel bad Nick, it brings up a valid question, even if it was buried about the same time as Jesus :

I have a collegue at with a 14 year old and 16 year old daughter and they both coo and go on and on about Fluffy to me. I feel like a dirty old man and have to either change the subject or leave the room when I pop over there!

martyrobertsdj

iTrader: (1)

What?? A deep throaty is cheaper than a vodka & coke??

TO THE TOON!!!!!!

Terminator X

iTrader: (7)

My Spec C doesn't "burble" however it still sounds amazing. Wife can hear the car from way up the street ...

TX.

MrRA

If that were the case, Porsches would sound similar.

I for one prefer the sound of my Spec C at full chat over the burble. Each to their own.

frayz

iTrader: (7)

All this talk of headers.

Im setting up a GB soon on the GT-Spec headers if anyones interested

Northern Nick

iTrader: (1)

I'm going for flat4's kakimei headers when I get mine,

Not to fussed about equal length.

I will say, a scooby with equal length header does have a slight sound of some Ferrari's

chocolate_o_brian

iTrader: (22)

mrdj, convoy!!!

Phildodd06

How much are they?
Is there much work involved fitting them
And will a remap be needed after?

bonerp

hmmm must have a problem with mine then

[Davey]

IMHO The Boxer 4 fires like a twin, i.e. the cylinders fire in pairs (which gives it the huge amounts of torque), front and rear which by its self gives a kind of "airy" noise, but combined with the un-equal length headers you get the distinct impreza noise.. Look at the VW flat four it doesnt sound like a scoob turbo and neither do the n/a scoobs to be fair

lloydster

how many guys on here get in there scoobs first thing in a morning
turn the key and just think...wow what a sound?

i do..i love the flat four sound of my beast....sounds awsome on choke

[Davey]

Technically its the "unequal header sound" and your car does not have a choke

Sorry I'm just being pedantic!

scooby abuser

so "normal" cars have all cylinders firing at once do they, must have a massive balancer shaft coz the vibratow that must give would be HUGE

Robin Mullan

Already got some mated to an APS 3.5" diameter race turbo back system, it doesn't sound too loud or good either

The rookie

iTrader: (1)

DOES IT F++K, the cylinders fire every 180 degress like any other normal 4 pot! And even if it did it wouldn't effect the average torque out at the wheels anyway, god what drivel!

The rumble comes from the unequal length runners meaning the gas pulses don't arrive at the collector with even spacing like they would if the runners were equal in length!

Simon

jasonius

iTrader: (1)

Lol, he does come from BERKshire..

[Davey]

If they dont fire in pairs how in gods name does the pair of coils work then

jasonius

iTrader: (1)

Ehhh..???

What pair of coils..?