Power (and how to get more?)

[Large]

I ran the Kat on a car dyno on thursday. I wasn't looking for maximum power but trying to get the mixtures right on the CRs so it doesn't foul the plugs. We were working on a 13:1 AFR as being ideal, so it's a bit lean down low

http://img341.imageshack.us/img341/4273/dyno16xd.jpg

That's 88hp[:I]

That was the last run and it picked up about 4hp by advancing the pickup the tiny bit that you can.

That isn't a lot of power for a 1200cc bike...So my questions are how do I economically pick up another 20-30hp?
TRE?
Advance the cams?
Better cams?
Little turbo?:D

[ozkat]

88hp? i think something is rather wrong, you did put 4 pistons back in, didnt you?;)

[fimpBIKES]

yeah that sounds a bit sad large

the SV was almost at 70hp with half teh capacity!!



ps- u smell
pps- kats rawk (if only i had one that worked....)

Somethings wrong Large. It's a gixxer with a 12 kit isn't it?

The original GSXR11 was 130hp (factory specs), and the original Kat motor was 110hp (factory specs). 88hp is about what the original 79' GSX11 was getting, at the back wheel.

Time for a visit to Mundy with a bottle of something?

[damo1]

Sell it and buy a Blade large stop kidding your self you know you want one.

[Large]

and there i was thinking if i posted the questions before the pubs opened i might get a serious answer[V]:D

[ozR1127]

[:0]88hp dosnt sound right large , what compression is the motor got? , i always thought the old air coolerd motors needed to run slightly richer off the bottom end ,what size jets are in these carbs?

[ozkat]

ozR1127 it gets worse, its not aircooled it a 1127 taken out to 1200

[Large]

quote:Originally posted by ozkat

ozR1127 it gets worse, its not aircooled it a 1127 taken out to 1200


you don't have to sound like you're enjoying it:D

[willow]

I'm thinking air/fuel is all wrong. Try richer all the way.

[pt]

yeah by my awesome powers of deduction it looks like 14:1 would be ideal, but i think if i actually worked out the equation 13 would be right. give me an hour and i'll figure it out. gotta love high school chemistry[V]

[Rocket]

Surely 88hp can't be right for one of those motors.
Is there parody between a car and a bike dyno ?
There's gotta be a big difference in the weight of the rollers, maybe that's affecting the reading.
Although you'd expect hp is hp and torque is torque when it's tied down to something.
If it was only putting out a low 88hp, you'd notice it on the road wouldn't you ?
I also thought dyno runs were done in fourth gear but the notes on the sheet say 3rd gear.

Maybe Ozkat was right, got any pistons left over?

Didn't I read somewhere a while back that you were messing around with head gaskets or was that someone else?
Maybe it's a compression problem.

[ozR1127]

[8D]i do believe the rollers are heavier on car dyno 's ,being a longer roller, what style of dyno was it ?, was there any clutch slip/ or wheel spin? are they the std cams ? where they dialed in? leaking head gasket/ leaky valves? a big 12 motor should have an honest 140 hp

[latheboy]

there is a program in the chassis dyno to run bikes all you do is tell the dyno what you wanna run.. the rollers make no differance believe me , i build these dyno's .. as for wheel spin it shouldnt happen if the guy running it knows what there are doin ..
and 88bhp doesnt sound good cause i got 97bhp with my 89 gix 750 and its standard

[TurboKat]

Get some adjustable cam sprockets & dial 'em in Large.

[pt]

pump it up to 14 all the way. stoichiometry says 14.7:1 but i think it'd get a bit rich in some spots if you ran that:)

[Captaintoc]

Hi mate

I have a few questions

1 What carb size and mains and are running pods or airbox?
2 What exhuast have you got on it?
3 Had the carbs balanced?
4 Compression good and within spec between cylinders?
5 Did you change heads and if so did you use you old cams/sprockets?
6 If you did change heads did you use your old cam caps?
7 Is the ride smooth or does it have hitches or strange noises?
8 Do you know what your comp ratio is?

Cause that motor should kick out 130-140 at the back wheel.

Have Fun
Andrew

[Large]

quote:Originally posted by turbokat

Get some adjustable cam sprockets & dial 'em in Large.


I'm onto it:)


quote:pump it up to 14 all the way. stoichiometry says 14.7:1 but i think it'd get a bit rich in some spots if you ran that

That's going too lean- The lower numbers are richer and about 13:1 is ideal. I checked out a couple of dyno charts in Rapid and they were right on 13:1 with an efi bike.

[Large]

quote:Originally posted by Captaintoc

Hi mate

I have a few questions

1 What carb size and mains and are running pods or airbox?

39mm Keihin Crs

quote:2 What exhuast have you got on it?

Full Yoshi Stainless

quote:3 Had the carbs balanced?

Nope...not before the run, but I balanced them on Saturday and it's running a lot smoother now...but it doesn't feel any faster

quote:4 Compression good and within spec between cylinders?

Haven't checked but it's got <500k old 1201 Wisecos in it

quote:5 Did you change heads and if so did you use you old cams/sprockets?

Yes. Yes. Yes

quote:6 If you did change heads did you use your old cam caps?

Yes

quote:7 Is the ride smooth or does it have hitches or strange noises?

It used to rattle a bit but since I balanced them it doesn't any more

quote:8 Do you know what your comp ratio is?

~ 11.5:1 at a guess


quote:Cause that motor should kick out 130-140 at the back wheel.

With stock cams?


quote:Have Fun
Andrew

[Captaintoc]

Yep with stock cams

Other thing you should have used the cam caps from the head you've got on it as they are a matched set.

You might want see if you've got the matching ones, if not get plasti-gauge and check clearances as they might be a bit tight and robbing the motor of a few ponies or they might be bad enough to fuck the top-end completely if your really unlucky.

P.S. when you do a comp check if the numbers are out a bit get a leak down test done if possible (to check for blow by).

Have Fun
Andrew

[ozkat]

Large ive just come back from Powerhouse Bike Dyno here at Nerang , and its not your bike its the dyno. You cant run a bike on a two roller car dyno with only 1 wheel spinning it. Simple as that.

[BOHEMION]

Yeah Large mate, head to a bike Dyno before you start to worry too much.

[Large]

and I was going to sleep in on sat[|)]

[willow]

Still thinking air/fuel.

[speeddemon]

pt

It not air:fuel - 14:1 is ideal combustion at 'cruising' but does not work like that on engines - you have shit power with ideal stoichiometry and need 13:1 to get better acceleration. Large you are right stick with 13:1 ignore the others....look at any dyno place and they aim for 13:1 for maximum power throughout the rev range.

My bandit made 117HP with stock engine and stage 3. Chadams old GPZ 1200 put out about a solid 135HP. I suspect dyno mate..

SUre it wasnt 88 kW???? still a bit low on power though, but may take up to 1k to get the best power as you did the pistons <500 ago

your shoe phone is ringing Agent 88.

[Large]

you an sanchez are fucking crack ups davy boy

[latheboy]

quote:Originally posted by ozkat

Large ive just come back from Powerhouse Bike Dyno here at Nerang , and its not your bike its the dyno. You cant run a bike on a two roller car dyno with only 1 wheel spinning it. Simple as that.

thats a big call oz

[IMP-INC]

88hp beats a stock 40,

[ozkat]

Well i asked the bloke that owns Powerhouse and thats what he said. I told him the said bike was near Newcastle so he had no reason to bullshit me. This is what he said to me (it may not be 100% correct) " The way dynos measure HP is by the amount of time it takes to spin the rollers from 1 set speed to another set speed (usually the rev limiter on the bike) The rollers on the Powerhouse weigh 400lbs, There are 2 sets of rollers (for rear wheels) on a 2wd car dyno which weigh proberly more than 400lbs each" Thats roughly what he told me, now i dont know if the 2 sets of rollers on the 2wd car dyno are conected or run seperately, i would think that putting a bike on a dyno that has the extra set of rollers would give a incorrect reading.i would say they are connected due to most cars having a non limited slip diff. Im not sure if all this is 100% correct

[fimpBIKES]

so does that mean he has DOUBLE what he thought he had??? :D

[pt]

wooops my bad. someone smarter will tell you how to fix it then[:o)]it seriously should be more than 88hp.

[Stocky]

Max Power 12.4 : 1 (.84 Lambda)

Best acceleration 12.8 : 1 (.88 Lambda)

Engines with less effiecient combustion up to 13.2 : 1 (.92 Lambda)

Emissions 14:1 ( 1 Lambda )

Lean cruise in a car 18 to 21 : 1 (it's a wonder that'll even burn)

[Rocket]

Large, have you found the problem yet ?

[Large]

not yet still looking

how do you adjust the timing on these? or do i need something like a dyna ignition?

[Booster]

Some car dyno's can be uncoupled to run as single rollers,
No bike dyno's near me so i'm looking to make a frame and use a local car dyno, not so concerned what hp it makes just want to be able to load it up and set mixtures.

Large how were you securing the bike??

[Large]

straps

one each side from the front of the seat area and down at about 45 degrees to hold it down

one each side from the swingarm to stop it kicking around and tipping over

a bracket to hold the front wheel is prolly a good idea though. something like the channel they use on trailers to support the front wheel with some angled side supports would do the trick

[Booster]

Should be soild enough, i was wondering if you may have had some wheelslip issues .

My dyno guy is keen for me to finish the frame , he sees it as a way to expand the business (and my dyno time will be real cheap) ;)