Four-stroke performance tuning?

[nudemetalz]

I hear so much about 2-stroke tuning lately ........ :yawn:

Let's hear some about the diesels. Lets talk about camshaft lift and duration,...about compression ratios,..about megas and header lengths.

Who's qualified to discuss this, as my 4st tuning knowledge is limited.

My Loncin engine has had a ported header (courtesy of Sully60), and hand made inlet manifold with a 30mm pumper and a home-made trumpet. Also utilise a GL-145 header with a KXF250 muffler.
The camshaft, piston and CR are all stock for now, giving it decent midrange.

[Skunk]

Four stroke?
Performance?
Huh? Doesn't compute... :confused:

[nudemetalz]

Four stroke?
Performance?
Huh? Doesn't compute... :confused:

Yeah, that's what they said when the first 4-stroke MotoGP bikes cames along and said bye-bye to the NSR's.........:laugh:

[Buckets4Me]

Yeah, that's what they said when the first 4-stroke MotoGP bikes cames along and said bye-bye to the NSR's.........:laugh:

ye what was it 1000cc 4stroke and only 500cc 2 stroke :done:

no wonder the 2strokes lost out they had to make twice the HP
and be reliable :jerry:

saying that it's all come a long way since then
things like traction controll and ABS brakes


also for all the 2strokers out there a cut and past

The first thing to note is that in order to change your bike into a four stroke, you need to remove the spark plugs. You will need to visit Repco, and buy a left hand direction spark plug remover. Simply replace the spark plugs with 4 stroke spark plugs. You will need a right hand direction spark plug inserter. I suggest printing out this advice and taking it with you, the car guys can be a little slow to understand.

You will also need to turn the direction of the motor around, 180 degrees. This is due to the power on the 4 stroke engine running the opposite direction as mentioned before. Be careful, I know a guy who forgot this, and he ended up starting his bike, opening the throttle, and then flying over the handlebars as he couldn't hold the weight of his ape, and his own body weight as the bike rapidly moved backwards.

Now, in order to turn the motor 180 degrees, you will need to buy the spark plugs mentioned above, but also a new back wheel. Make sure it is made in the correct part of the world. It gets really confusing, and if you get the wheel wrong, the bike will either be really fast (wheel rotating in the same direction as the motor) or it won't move at all (wheel cancels out the motor).

The world of motorcycling can be very confusing with lots of poor advice, lucky you came to the right place first. WhiteTrash has a very high score beside his name, that's because he is all wise, and all knowing.

Finally, you will need a set of decent ape hanger handle bars as MsKaBC suggests, sportsbikes can be hard to handle, so you need to assure yourself that you've got all the right parts. I'd suggest going to see Tony at Haldane's, that's in Penrose, Auckland, and explain you need a set of ape hangers for your bike, and tell him you need the sort with a long weight.

It might take you some time for him to find the part number, but I assure you, they will be worth it. Valentino Rossi has a pair, look how fast he is.

Kind regards, MadBikeBoy.

and more

Oh, one more thing, I was just talking with someone who went through the process - your bike is sometimes referred to as a rice burner. This is not accurate, your bike runs on normal petrol, and not on rice squeezings. With some additives, you might consider using rice squeezings instead. You will need to buy a loose nut adjuster (about $50), and a big vat, you can find them on trademe - they're used for distilling whisky. As luck would have it, WhiteTrash has one of these, actually, he has several of these - he uses them for his moonshine distillery.

So, once you have the vat, and the loose nut adjuster, you need to boil about 5 kg of long grain rice (don't use short grain rice, it's too volitile). You will need to boil the rice for about 2-3 days, and all the vapour gets collected in the pipework, (just like whisky distilling, and this is how petrol is distilled), and then you let that sit for about a week. WhiteTrash, you're the expert here, help me out if I've got any of the detail wrong.

So, once you filter that, you're reading to put the rice squeezings in your bike. You will need to suck the petrol through, I'd just attach a hose to the exhaust port, you'll be able to tell when you start to taste the liquid come through.

Then, once you're good to go, just hit the starter button. Some people experience problems at first, but once your rice burner is actually running on rice, it will sound distinctly different. If you've ever heard the wonderful sound of a Honda VTR twin, that's what your bike will sound like, and it's very impressive.

Regards, MBB

[TZ350]

4-stroke and performance, can't legaly get the two words to go together can you?????

.

[AllanB]

4-stroke and performance, can't legaly get the two words to go together can you?????

.

I think someone has been stroking 'something' more than 4 times.............:laugh::laugh::laugh:

[Sketchy_Racer]

I think someone has been stroking 'something' more than 4 times.............:laugh::laugh::laugh:

No it was just four strokes. I counted.

[nudemetalz]

sheeeeez,...I think I'm sorry I brought up this thread...... :shit:

[quallman1234]

Here's alex barros, showing why 2 strokes are so cool.

It was shot in 02'? When the switch was made, just look at his corner speed! compared too the 990's, ofc that would be different these days with the 800's being very light.

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/1gH3SeSqzdE&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/1gH3SeSqzdE&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

[AllanB]

Here's alex barros, showing why 2 strokes are so cool.

It was shot in 02'? When the switch was made, just look at his corner speed! compared too the 990's, ofc that would be different these days with the 800's being very light.

Cool t hay were, but in reality the 2 stroker had had years of GP development at that stage and the 4's were new - kind of like Hoyosung entering Moto GP today - it may take a few years for them to get up to speed! (be interesting to see what BMW does).

You'd find that same impressive 2-stroke is probably a P.O.S competing with the current electronic masterpieces in MotoGP.

I have read a few books by riders of those 2 stroke GP bikes - the yall describe them as untamed monsters!

At the end of the day if they were still that bloody good they will still be on the track today as you race what wins.

[Skunk]

sheeeeez,...I think I'm sorry I brought up this thread...... :shit:
Nah, it's good entertainment.

[Sketchy_Racer]

sheeeeez,...I think I'm sorry I brought up this thread...... :shit:

Common man, you're asking for it when you put 'Loncin' '4 Stroke' and 'Performance' in a thread.

[ajturbo]

good old "peter sales" is the man...
what he doesn't know, the japs haven't invented yet

[Buckets4Me]

You'd find that same impressive 2-stroke is probably a P.O.S competing with the current electronic masterpieces in MotoGP.

I have read a few books by riders of those 2 stroke GP bikes - the yall describe them as untamed monsters!

At the end of the day if they were still that bloody good they will still be on the track today as you race what wins.

of course they would be
but then we have rs250 honda's now if you made them an inline4 with 990cc dispalacement with all the electronics wiz bang of today then you may have a chance of taking on an F1 car
the mighty 2 stroke never had a chance
it was a case of if we cant beat it we will rule it out of the running :shifty:

now lets make buckets more fun
F4 150cc watercolled 2stroke ???? wonder weather you will find a 4stroke in sight :laugh:
F5 100 watercooled 2stroke :2guns: just so those old f5 bikes can still be used

or we could follow the GP bikes and say 200cc 4stroke and only 100cc 2stroke :no: (that way you can say that 4 strokes are faster and prove it at the same time):jerry:

[koba]

I hear so much about 2-stroke tuning lately ........ :yawn:

Let's hear some about the diesels. Lets talk about camshaft lift and duration,...about compression ratios,..about megas and header lengths.

Who's qualified to discuss this, as my 4st tuning knowledge is limited.

My Loncin engine has had a ported header (courtesy of Sully60), and hand made inlet manifold with a 30mm pumper and a home-made trumpet. Also utilise a GL-145 header with a KXF250 muffler.
The camshaft, piston and CR are all stock for now, giving it decent midrange.

4 stroke tuning is EASY!

ACTIVATE ZAVANCE!

Seriously though, Mr Bell who wrote one of the very good two stroke tuning books as also written a great one on four stroke tuning, it is very good and will have information relevant to your loncin.

[F5 Dave]

Cool t hay were, but in reality the 2 stroker had had years of GP development at that stage and the 4's were new - kind of like Hoyosung entering Moto GP today - it may take a few years for them to get up to speed! (be interesting to see what BMW does).

You'd find that same impressive 2-stroke is probably a P.O.S competing with the current electronic masterpieces in MotoGP.

I have read a few books by riders of those 2 stroke GP bikes - the yall describe them as untamed monsters!

At the end of the day if they were still that bloody good they will still be on the track today as you race what wins.

Bring it on.

The 500cc class used to be just that. 500cc of 4 cylinder do what you want. Honda tried to compete with oval pistons, fists full of valves & whatnot - but failed dismally. Make the class 500cc & open to all naturally aspirated engine types & see that the only real racing engines would be what they always were. Until Ghey old men F'd with the class. & where has it got them now? Boring racing & they know they are in trouble.

But the new class had to beat the old class of 500s so they made them twice as big. The F2 class is even more silly, 600cc fours against 250 twins. Gee that's fair.

[AllanB]

Until Ghey old men F'd with the class. & where has it got them now? Boring racing & they know they are in trouble.

But the new class had to beat the old class of 500s so they made them twice as big. The F2 class is even more silly, 600cc fours against 250 twins. Gee that's fair.

I'd forgotten about the 500-990 displacement.....:shit:

Silly really as who was going to tame a 900cc 2 stroke :laugh::laugh:

Not sure how they derive their formula for the comparison - presumable due to firing 2 against 4?

An open class would be exciting and innovative for sure but ultimately whoever produced the fastest would probably be copied by the others.

Oval pistons - their original theory was to skirt the racing rules - they were aiming for a V8 engine but still presented as a legal V4 (only 4 cylinders even if they were oval.....). innovative for sure but doomed early on and I think it was corporate pride that allowed it to continue as long as it did.

[speedpro]

Not sure how they derive their formula for the comparison - presumable due to firing 2 against 4?

An open class would be exciting and innovative for sure but ultimately whoever produced the fastest would probably be copied by the others.

They derived the formula based on how big a 4-stroke engine was needed to beat a 500 2-stroke.

As for an open class leading to copying you only have to look at bucket racing to see that NOT happening. Bucket racing probably has the least rules of any form of motorsport and there is still a huge variety. Hell, some people are even racing 4-strokes.

On the more serious MotoGP side, within a set of rules there has to be only one ultimate configuration but there seems to be quite a variety still. Don't forget that even at this level that the marketing guys will be having a say in what gets designed, built, developed, promoted and sold. Racing after all is just a way of promoting your brand.

[AllanB]

at this level that the marketing guys will be having a say in what gets designed, built, developed, promoted and sold. Racing after all is just a way of promoting your brand.


Which makes you wonder just why did Honda not capitalize on the V5 configuration a few years ago in a street version :blink:

A question asked may times, and I personally suspect any gains made in the engine over their IL4's on the street were limited.

Either that or they are gay.....

[UNSTABLE]

Which makes you wonder just why did Honda not capitalize on the V5 configuration a few years ago in a street version :blink:

A question asked may times, and I personally suspect any gains made in the engine over their IL4's on the street were limited.

Either that or they are gay.....


Quite simple really, it costs more to produce a 5 cylinder V engine compared to an inline 4. Joe punter would have to foot the bill in the end for very little return in performance, as the road version of a 1000cc bike these days is far more than most throttle jockeys can handle...

[Buckets4Me]

http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Motorbikes/Sports/auction-224536122.htm

here you go I'm sure you could have the rules changed to allow this in F$
I mean F4 and then 4 strokes would start winning

:shutup: and I wonder what the balance factor on that would be

[Kickaha]

So who can tell me anything useful about rod to stroke ratios?

[k14]

The higher the rod to stroke ratio the closer you are to an explosion...

[Buckets4Me]

So who can tell me anything useful about rod to stroke ratios?

Rod to stroke or Bore to stroke ??

not sure but I always thought that a square ie same bore stroke was a good compromise

nissan thought a short stroke was the way to go and toyota like it over sqare a bit

always thought that short stroke more revs (hp) at top end
longer stroke more touque less revs better pull out of corners

thats my uneducated guess

(sits back and waits for people to correct him)

[Kickaha]

Rod to stroke or Bore to stroke ??


Rod to stroke

[speedpro]

Kawasaki used a 2mm longer rod in their ZXR750s they raced at one time and Yamaha went to a 2mm longer rod in the 3LN FZR250 with a correspondingly shorter piston. Due to geometry as the crank rotates the peak piston forces are reduced which if you take advantage of that allows you to use higher revs an not exceed the limits.

If the rod was infinitely long the piston velocity would vary at a times 1 sinusoidal rate with crank rotation. As the rod is shortened peak acceleration and peak velocity increase. I can visualise it but the math escapes me.

Short stroke and long rods allow an engine to rev higher without exceeding mechanical limits. Engineers design engines to take advantage of this with the result that most people think that a short stroke engine is peaky and high revving "because" it it short stroke.

[speedpro]

Short rods will increase piston thrust face pressure as well.

Actually the more I think of this the more I remember there is to consider. Things like pressure gradients in the cylinder versus piston acceleration about TDC versus crank/rod geometry.

A good mod for the V8 boys is to fit a 400 crank into your 350 block. They end up with a longer stroke but have to use shorter rods. The rod length to stroke ratio changes a lot. You end up with a pretty grunty 380ish motor. Grunty partly because of the increase in capacity but also due to the rod/crank geometry. Thrust face forces increase because of the angle the rod is at as combustion forces push the piston down and also as the crank rotates and the piston is pushed back up.

[Ocean1]

So who can tell me anything useful about rod to stroke ratios?

Variable is rod length but critical factor is rod angle.

Sine of Rod Angle = Stroke ÷ (Rod Length * 2)
(or)
Sine of Rod Angle = .5 ÷ R/S



Rod Angle “n” Ratio Examples Comments
13½° 2.142-1 High speed motor with small ports. Best breathing with small ports
14° 2.067-1
14½° 1.997-1 Long rods for good breathing with small ports
15° 1.932-1 Long rods to help breathing with small ports. Responds well to stroke increases (“n” value too large for intake port size)
15½° 1.871-1 Responds well to stroke increases (“n” value too large for intake port size)
16° 1.814-1 Approximate “ideal” compromise between stress & breathing (1.81-1)
16½° 1.760-1 Good choice for motors with good breathing
17° 1.710-1 ”Safe” limit for thrust angle. Approaching practical limit for street motors
17½° 1.663-1 Approaching practical limit for street motors
18° 1.618-1 Approaching practical limit for street motors. Good power due to large intake port
18½° 1.576-1 Limited street use
19° 1.536-1 Good power due to large intake port
19½° 1.498-1 Not practical for street use due to short pistons
20° 1.462-1 Poor peak power. Longer rods are not used in any serious application

[TZ350]

Variable is rod length but critical factor is rod angle.

Sine of Rod Angle = Stroke ÷ (Rod Length * 2)
(or)
Sine of Rod Angle = .5 ÷ R/S



Rod Angle “n” Ratio Examples Comments
13½° 2.142-1 High speed motor with small ports. Best breathing with small ports
.


My rod is 110mm and stroke is 50mm.

Sine of rod angle = 50 / 110 * 2)

Sine of rod angle = 50 / 220

Sine of rod angle = 0.227

..........rod angle = 13 1/8 degrees (13.12 deg)

Have I got this right???? does this make my motor Best breathing with small ports ??????.

Hope so because small transfer ports is what I have on the Suzuki GP125.
.

[Ocean1]

...There's stuff missing.

Here:

Effects of Long Rods
Pro:
Provides longer piston dwell time at & near TDC, which maintains a longer state of compression by keeping the chamber volume small. This has obvious benefits: better combustion, higher cylinder pressure after the first few degrees of rotation past TDC, and higher temperatures within the combustion chamber. This type of rod will produce very good mid to upper RPM torque.
The longer rod will reduce friction within the engine, due to the reduced angle which will place less stress at the thrust surface of the piston during combustion. These rods work well with numerically high gear ratios and lighter vehicles.
For the same total deck height, a longer rod will use a shorter (and therefore lighter) piston, and generally have a safer maximum RPM.

Con:
They do not promote good cylinder filling (volumetric efficiency) at low to moderate engine speeds due to reduced air flow velocity. After the first few degrees beyond TDC piston speed will increase in proportion to crank rotation, but will be biased by the connecting rod length. The piston will descend at a reduced rate and gain its maximum speed at a later point in the crankshaft’s rotation.
Longer rods have greater interference with the cylinder bottom & water jacket area, pan rails, pan, and camshaft - some combinations of stroke length & rod choice are not practical.
To take advantage of the energy that occurs within the movement of a column of air, it is important to select manifold and port dimensions that will promote high velocity within both the intake and exhaust passages. Long runners and reduced inside diameter air passages work well with long rods.
Camshaft selection must be carefully considered. Long duration cams will reduce the cylinder pressure dramatically during the closing period of the intake cycle.


Effects of Short Rods
Pro:
Provides very good intake and exhaust velocities at low to moderate engine speeds causing the engine to produce good low end torque, mostly due to the higher vacuum at the beginning of the intake cycle. The faster piston movement away from TDC of the intake stroke provides more displacement under the valve at every point of crank rotation, increasing vacuum. High intake velocities also create a more homogenous (uniform) air/fuel mixture within the combustion chamber. This will produce greater power output due to this effect.
The increase in piston speed away from TDC on the power stroke causes the chamber volume to increase more rapidly than in a long-rod motor - this delays the point of maximum cylinder pressure for best effect with supercharger or turbo boost and/or nitrous oxide.
Cam timing (especially intake valve closing) can be more radical than in a long-rod motor.

Con:
Causes an increase in piston speed away from TDC which, at very high RPM, will out-run the flame front, causing a decrease in total cylinder pressure (Brake Mean Effective Pressure) at the end of the combustion cycle.
Due to the reduced dwell time of the piston at TDC the piston will descend at a faster rate with a reduction in cylinder pressure and temperature as compared to a long-rod motor. This will reduce total combustion.

Angle Limitation

The angle of the rod at 90° ATDC is a good indication of how much stress the piston and cylinder wall will be subjected to with a specific rod/stroke selection (this is not the angle of maximum thrust, which occurs when the rod’ beam axis is at 90° to the crank throw or journal, typically between 70-76° ATDC; however, the math is easy to do). Angles beyond 17° (where the rod axis is 90° to the crank throw at 73° ATDC) promote excessive wear at the piston major thrust surface, and piston breakage could be the result. Before you purchase connecting rods that are shorter than previous or increase the stroke of the crank, calculate the new rod angle. High rod angles will require quality rods that have been checked for cracks and have quality fasteners. Piston selection will be critical for the life expectation of the engine; maximum skirt length below the pin is desired.

[TZ350]

.

Thats very interesting reading. Thanks.

.

[speedpro]

Long rods in a 2-stroke may be a benefit due to the extended dwell at BDC. The time/area of the ports is increased whilst retaining the area of the ports.

Back to the dark side . . . . . .

I stopped in to see the guys at a cylinder head shop in the USA a few years ago. They supplied heads to people like Mercury Marine and a number of top drag racers. The information they wanted to ensure the correct head specifications was amazing and included things like rod length. The top guys were changing heads with cam or pistons and rods. They were doing CNC porting and cutting heads in 2 and then welding them back together with the front pair of cylinders spaced further away from the rear pair to fit on mountain motors. I got the guided tour from the main man and learnt lots from that couple of hours.

[Ocean1]

Long rods in a 2-stroke may be a benefit due to the extended dwell at BDC. The time/area of the ports is increased whilst retaining the area of the ports.

Dunno about rod length ratios on 2 strokes.

But :laugh:.

A 2 stroke will create an intake pressure wave as it accelerates away from BDC. At BDC you get a much less less pronounced acceleration plot compared to that at TDC, but more to the point the effects of rod ratio on piston acceleration are the inverse near BDC.

On a 2 stroke I'd be interested in how that affected squish velocity. :sherlock: Mebe not a lot, not much variation that close to TDC...

[speedpro]

I just did the numbers for a stock MB100 and got 14.33deg rod angle and for the new high revving Wobbly spec engine with reduced stroke and longer rod I got 13.213deg.

Interesting to see that so far both 2-stroke examples are down one end of the range from Ocean1 and they aren't high spec engines. A couple of examples from the "dark side" would be interesting for comparison.

[speedpro]

but more to the point the effects of rod ratio on piston acceleration are the inverse near BDC....

Obvious when it's mentioned, simple geometry and all that, but I had never thought of it. Do you have any graphics you can post plotting velocities and various crank positions versus rod ratios?

[speedpro]

Perhaps Ocean1 could comment on "offset boring" cylinders as well. Fairly obviously it will affect rod angle in opposite directions depending on crank position.

[Ocean1]

Do you have any graphics you can post plotting velocities and various crank positions versus rod ratios?

I don't, much as radial graphs would be quite illuminating. Guess someone could write a wee macro so we could dump experiments in and get comparitive graps out. Unfortunately I don't have time.


Perhaps Ocean1 could comment on "offset boring" cylinders as well. Fairly obviously it will affect rod angle in opposite directions depending on crank position.

Ocean1 is on his sixth dram and will be making no comments involving quantifiable conclusions. Is a good idea though, if for no other reason than ideal piston velocity profiles from 180-0 are always going to be different to ideal velocity profiles from 0-180. Don't know why it's not more common.

[Kickaha]

when we had a 125 limit I had a bore and stroke of 57 x 48.8 and a 106.4 long rod,the rod/stroke was 2.18 and the bore/stroke 1.16

when we went to 140cc we stroked the cranks to get 57 x 54.6 so the rod/stroke stayed the same but the bore/stroke changed to 1.04

Then with the 150cc limit we went to 59 x 54.6 so still the same rod/stroke but bore/stroke changed again to 1.08

The next engine is going to be 66 x 44.8 with the same length rod so it will end up rod/stroke 2.37 and the bore/stroke 1.47

I had a few goes at working out the rod angle but fucked it up every time, must be why I failed school c maths :lol: somone help me out ta

[TZ350]

rod is 106.4mm and stroke is 48.8mm.

Sine of rod angle = 48.8 / 106.4 * 2)

Sine of rod angle = 48.8 / 212.8

Sine of rod angle = 0.229

..........rod angle = 13 1/4 degrees for Stroke = 48.8mm


rod is 106.4mm and stroke is 44.8mm.

Sine of rod angle = 44.8 / 106.4 * 2)

Sine of rod angle = 44.8 / 212.8

Sine of rod angle = 0.210

..........rod angle = 12 1/8 degrees for Stroke = 44.8mm


For Sine of rod angle = 0.210 use the Sine-1 function on your calculator to get 12.122 Degrees. More or less 12 1/8 degrees. Also instead of 1/8 could use minutes of a degree.

.

[Kickaha]

Ta and the 44.8 stroke would be rod angle 12.12

I'm fucking sure you didn't have that up there originally or am I going blind?

[TZ350]

.

There is another way to state the size of an angle, one that subdivides a degree using a system different than the decimal number example given above. The degree is divided into sixty parts called minutes. These minutes are further divided into sixty parts called seconds. The words minute and second used in this context have no immediate connection to how those words are usually used as amounts of time.

In a full circle there are 360 degrees.

Each degree is split up into 60 parts, each part being 1/60 of a degree. These parts are called minutes.

Each minute is split up into 60 parts, each part being 1/60 of a minute. These parts are called seconds.

The size of an angle could be stated this way: 40 degrees, 20 minutes, 50 seconds.

There are symbols that are used when stating angles using degrees, minutes, and seconds. Those symbols are show in the following table.

Symbol for degree: 0

Symbol for minute: '

Symbol for second: "

Bit of info from id.mind.net
.

[TZ350]

I'm fucking sure you didn't have that up there originally or am I going blind?

Your right, I did it in two bits.

[speedpro]

The thing I've been wondering about lately is - if you had a 180deg twin what would be the best thing to do with the exhaust going to the turbo. It seems like some sort of plenum chamber, but what length headers - tuned or not, what volume chamber, length of pipe from chamber to turbo, design of chamber, or no chamber??? More or less same questions for the intake. I did read somewhere about this but it was a bit vague on things like lengths and how to determine optimum volume.

[Yow Ling]

The thing I've been wondering about lately is - if you had a 180deg twin what would be the best thing to do with the exhaust going to the turbo. It seems like some sort of plenum chamber, but what length headers - tuned or not, what volume chamber, length of pipe from chamber to turbo, design of chamber, or no chamber??? More or less same questions for the intake. I did read somewhere about this but it was a bit vague on things like lengths and how to determine optimum volume.my understanding is you need to have the volume of at least 1 cylinder for an uneven firing enginein the inlet, I have a 550 cc twin turbo engine in a car it has 360 deg crank and has a plenum volume of more than a litre s maybe just the bigger the better. Dont think the exhaust is so critical

[Skunk]

The thing I've been wondering about lately is - if you had a 180deg twin what would be the best thing to do with the exhaust going to the turbo. It seems like some sort of plenum chamber, but what length headers - tuned or not, what volume chamber, length of pipe from chamber to turbo, design of chamber, or no chamber??? More or less same questions for the intake. I did read somewhere about this but it was a bit vague on things like lengths and how to determine optimum volume.
What are you building now?...

[F5 Dave]

now? I think he started before my 100:lol:

[Skunk]

Someone once told me "one project at a time". For some reason I don't think that advice is very widely used...

[Kickaha]

Someone once told me "one project at a time".


That's just stupid talk

[Buckets4Me]

Someone once told me "one project at a time".

STUPID stupid STUPID


1 I have a family project #1
2 I have a bucket project #2
3 I have another bucket #4
4 I have a post clasic race bike #5
5 I have a skyline drag car #6 ( cost to much compared to buckets )
6 the kids play RUGBY #7 #8 #9
10 the wife has a horse
11 I had a garden
12 an unfinished deck (+ kids)
13 I have a Wife :sweatdrop