horsepower - conflicting data

Hi,

I'm very new to this forum - only found it on the weekend but unable to get the 'introduce yourself' function to work.

I have a 2010 GSX 1250 FA (arguably the best bike I have ever owned for all 'round 'bang for ya buck') - anyway, my question is this; there seem to be conflicting reports about the horsepower produced by the standard bike - some sites quote as low as 91 bhp whilst others quote 98bhp.

So which is it?

Adding to my confusion, I fitted a Staintune can & firmly believe that the bike's performance is much crisper. However, I took my bike into Peter Stevens for its 6,000km service today & they put the bike onto the dyno (Dynojet Performance Evaluation Program) & it only achieved 97.19bhp - this is despite Staintune's claim to provide 5 - 10bhp.

Any comments?

Cheers,
Silver

Hi ho Silver (sorry, couldn't resist! ). Welcome aboard.

I dyno'ed my 2010 1250s before and after fitting the Yoshi R77 (no other mods). Results were:
Standard: Peak power - 92.12 hp; Peak torque - 75.09 ft-lbs
Yoshi R77: Peak power - 98.94 hp; Peak torque - 79.61 ft-lbs

I posted the dyno charts elswhere on the forum some months ago.

hi and welcome....mine is bog standard and still has enough buzz for me ...I call him "Buz the Bandit".....with a little toy Buzz Lightyear attached...............Grumpy ( yea yea I know ..pathetic..get a life..etc )

Hi Silver

Much of the results of a dyno depend on things like altitude, setup, operator etc. The main thing is the difference between dyno runs.

A pipe with no other mods doesn't make a large difference in my opinion. The bike may spool up faster and sound quicker, but a lot of the apparent gains are quite subjective. The engine's essentially a large pump, and allowing more exhaust gas to come out needs to be balanced with allowing more air and fuel at the appropriate air/fuel ratio to come in. A pipe by itself is half the equation, just like adding a power commander without a filter and pipe doesn't make a lot of difference either.

The biggest gains we have all made are a combination of pipe, improved airflow through a less restrictive filter and airbox mods, and the addition of extra fuel at the appropriate A/F ratio with a TFI or Power Commander. A lot of us have also removed the secondary butterflies to provide improved air flow and peak horsepower with the other mods.

A Stage I kit puts out about 114 hp, the stage II about 122, and the stage II with a full exhaust system (less restrictive headers) around 132 hp.

The 1250 motor, however, is all about peak torque, and the stage II torque (Dale walker quoted) is about 92.4 ft-lbs, which is huge. Have a good look through the site, as there's a lot of info on it. My bike is Stage 2 with better rideability, a lot more power, great sound and similar fuel economy.

The Dale Walker setup is quite literally plug and play - you buy the kit, it's easy to install (unless you knock off the IAP sensor line.... ) and you don't need to go near a dyno. The Power Commander route is similar and it's really a case of personal choice.

Working on the bike is a lot of fun and the gains are great!

Dont worry about the numbers ,your arse will tell you there is enough mumbo .Top speed is unimportant 99.9% of the time.

Thanks for all the responses. As soon as I have figured out how to send comments on individual responses I will do so, until then, here's a general response.

Just to clarify; I am more than happy with the performance of the bike, I was just curious about the sometimes conflicting data.

Kewwig: your info made a lot of sense - thanks.

Gus: you hit the nail on the head!!!

Grumpy: we sound very alike.

Ewok: thanks - I will see if I can find them.

I think I will gain a lot of info & have a few laughs on this forum.

Cheers,

Silver

You have the Posting Thing worked out .A general reply is fine IMHO .

Hello and welcome - seems more are joining in Adelaide - see ya out and about sometime

Welcome to the forum.
Firstly you have a double gain.
1. You gained a few more HP even as stock
2. You have saved about 7kg which it's self is worth an extra pony
Oh and there is a third you wont put out the heat of a nuclear reactor even an hour after turning the mill off.

Replace the headers with some Arrow race pipes and you lose 9Kg's. The end pipe has to be at least a kilo or two weight saved.

Go on a diet and the bike will feel even more powerful

I seriously recommend the pipes, but the police and greenies might have other ideas.

Morning,

Thanks for all the responses (even the diet suggestion, Reddog....) - plenty of food for thought. I'm actually quite impressed with the forum - I have been on others over the years with very little activity, so this one is refreshingly good.

It's a nice day in Adelaide today, so going for a run up through the hills to Birdwood (need more bits for my vintage bike), then on Thursday me & a pal are heading off to Mildura then up to Broken Hill & back via Yunta & Burra. Should be a good few days & may even dodge the rain.

Gotta go - the sun is shining!

Silver

Sounds like fun. The weather in WA is appalling at the moment.

What sort of vintage do you have? I wouldn't mind an old Honda CB750 or something like that to play with.

reddog wrote:...Go on a diet and the bike will feel even more powerful ....

A mate of mine used to spend a fortune shaving a few grams here and there off his GSXR. I always chuckled to myself as he'd have gained far more effective horsepower losing his gut.

I have had to go to Stage II just to get past 50ks......

reddog wrote:What sort of vintage do you have? I wouldn't mind an old Honda CB750 or something like that to play with.

This might fit the bill reddog (if you're not set on a Honda):
http://www.bikepoint.com.au/all-bikes/private/details.aspx?R=10543447&__sid=128A82347990&__Qpb=1&Cr=1&MileageTo=1584&keywords=&__N=1432%20604%201430%201429%201626%201428%204294967215%20750%20686%201584%201470&PriceFrom=750&PriceTo=686&seot=1&__Ns=p_IsPoa_Int32%7c0%7c%7cp_RankSort_Int32%7c1%7c%7cp_HasPhotos_Int32%7c1%7c%7cp_Make_String%7c0%7c%7cp_Model_String%7c0%7c%7cp_YearMade_Int32%7c1%7c%7cp_PriceSort_Decimal%7c1%7c%7cp_PhotoCount_Int32%7c1&__Nne=15&trecs=9&silo=1400

A zx9? I'd have a 7 over a 9 anyday.

My brother picked up a 2000 ZX7 and it's a great bike to ride.

...plus if I buy another bike my wife will not be happy. 6 bikes so far may be a little excessive.

Welcome to the forum Silver.

gus wrote:I have the Posting Thing worked out

Yes you do Gus

Reardo wrote:Welcome to the forum Silver.

gus wrote:I have the Posting Thing worked out

Yes you do Gus

And welcome to the forum, Silver

Hi reddog,

I have a 1939 Acme 125cc 2 stroke, single barrel with twin, fishtail exhausts.

I was on a film shoot in the Mundi Mundi plains area near Silverton (north west of Broken Hill) about 12 years ago & happened to meet a bloke who knew a bloke......... anyway, I bought the bike & after having it sit in bits for years, I have only just finished the re-build. Just got to source some 6volt globes & I'm ready for the famous Bay to Birdwood run, in September.

I also have my old Observed Trials comp bike, too - a 1974 Yamaha TY 150. I've re-built it twice but don't take it out anymore which is a shame really.

Continually lament (as probably most of us do) the fact that I didn't keep some of my very first bikes; my 1954 Triumph T20 Tiger Cub. My 1959 Triumph 5TA 500cc Speed Twin.......

Anyway, whilst I'm certainly no expert & I admit to being very slow, I really enjoy tinkering with the older bikes - probably 'cos they're easier to understand, well for me.

Silver

Tinkering is good. The Bandit, even with EFI, is straight forward. Some of us fiddle till we break stuff (or melt it ), but generally there's enough collective wisdom (or bitter experience) here to make most stuff straight forward

Some of us fiddle till we break stuff (or melt it )

Ohhhhh..... that's just NASTY!!

My mate has a '74 ish Yamaha TY175 Trials bike that he is doing up. He has been buying bits and pieces from the UK as they are quite popular. I bought it off the next door neighbour for $50 and swapped my mate for some electrical work when my wife and I were renovating

As a kid we had Little XL Honda's and a few Yamaha 2 bangers in the form of a DT 175 and DT400. I do like going to vintage bike evetns or swap meets to check out some of the stuff we used to ride.

reddog wrote:
As a kid we had Little XL Honda's and a few Yamaha 2 bangers in the form of a DT 175 and DT400. I do like going to vintage bike evetns or swap meets to check out some of the stuff we used to ride.

I had a DT 400 (D?). Could just hang on when opened right up. Had the worst tank-slappers on that bike. Scary memories. Ah, the good old days. Not.

I found this chart for the '11 GSX1250FA on a US site....



That's an incredibly flat torque-curve! Pretty much maximum torque all the way from 3,000 to 6,500rpm! Looks like there probably not a whole lot of point going much over 7,500rpm?

I do miss those kind of curves. This is what mine looks like now

Can we have one with the secondaries removed .I out on the bike today ,i'll gun it and see if it keeps pulling past 7.500.
I'm sure it does