gsx-r 93 GSX-R 1100 WP advice needed

[JezzR]

Hi,

I've been searching the web but sadly can't find an answer, I'm in need of an expert! I've bought a 1993 GSX-R 1100 WP, great bike but not one I know a great deal about and as they're getting on a bit, not a lot of info on them. The bike is completely standard, only done 23,000 miles, seems to have spent most of it's time in garages, still has the original twin exhausts! not had any modifications. I've had the carbs cleaned, rebuilt and balanced, then put on a rolling road.

My question;

The output on the rolling road was 125 bhp - stock. What info I've been able to find online suggested 155 bhp? I have heard that some bikes of the time were restricted (four plugs in the carbs), is my bike still restricted or is this the best it can do without specialist tuning?

Any help would be greatly appreciated.

[Gixer1460]

if you are quoting stock horsepower (155) then the manufacturers tend to quote crankshaft horsepower not rear wheel. Yours is a bit down as i would expect 10% difference on average?

[caferacerdan]

from what I have heard, the stock exhausts on most of the old suzi's are extremely restrictive and do strangle the motors

[wombat258]

The Dynojet  dyno figures add about 15% to rear wheel hp correct up for flywheel horsepower. I have not come across restrictors, but different countries restricted the carbs down from 40mm to 38mm. After 23 years you would expect the engine to be down on power.

[Gixer1460]

3 hours ago, wombat258 said:

The Dynojet  dyno figures add about 15% to rear wheel hp correct up for flywheel horsepower. 

Who told you that? RR Dynojet dynos only give rear wheel horsepower - nothing else! It may be converted / corrected to recognised standards but its still power at the wheel. Unlike car dynos there is not enough inertia in a bike driveline to obtain a 'losses' figure so any crankshaft figure is purely speculative.

[wombat258]

No, it is a fact. Good mate of mine bought a top end eddy current brake Dyno that read true rear wheel horsepower. Customers complained that his dyno read lower than local Dynojet inertia dynos, so he went back to the manufacturers who were fully aware of the correction factor required. They added in the correction factor and everyone was happy. I could find out the exact factor . . . I am sure it was 15 to 16%. That is why you need to know what dyno and what correction factors are used to produce charts. A lot of things affect the dyno readings . . . and a lot of operators know how to exploit that.

[JezzR]

Thanks everyone for getting back to me. The chart says air correction SAE J1349, DJHP corrected power? Exact figures;

1-Dyno run.dpr: Max power 125.38 bhp @ 10862.3 rpm, max torque 67.33 ft/lb @ 8953.9 rpm

4-Dyno run.dpr: Max power 125.72 bhp @ 9918.2 rpm, max torque 69.99 ft/lb @ 9031 rpm

Think i read somewhere 136 hp at the back wheel, so I may have lost a few horses somewhere? It's not exactly slow but I would like to get a bit more out of it, don't want to go mad and possibly mess up the engine but could anyone recommend any tuning options, and due to my limited experience anyone who could do it?

As caferacedan mentioned, the exhausts look like a start, don't want to go 4:2:1 as I like the look of the twin exhausts, just something that could improve the flow and sound better. Could anyone recommend any replacements and/or specialists that can help?

[SiBag]

The 155 BHP figure quoted by Suzuki and Bimota, was at the crank, and it was a bit of an exaggeration.

I know most of the guys on the Bimota forum that run SB6's are all seeing about 130BHP at the rear wheel, so your 125 sound good to me

PS.

The Bimota SB6 runs the GSXR1100 WR / WS motor.

Edited June 1, 2016 by SiBag

[JezzR]

Many thanks, so taking in correction factors at the dyno 125 bhp is starting to look respectable considering its a standard engine, no mods and 23 years old. To be honest I'm finding the riding position difficult to live with, especially after an hour in the saddle so considering selling it. It was the bike of my youth, the bike I waited to see sat on the wall of the local pub on rock night, always said I'd have one so boxed ticked. Great bike, still turns heads wherever it goes but maybe its a case of shouldn't meet your heroes.

Thanks everyone for your time and advice.

[Del]

On 25/05/2016 at 11:41 PM, JezzR said:

 still has the original twin exhausts! not had any modifications.

The output on the rolling road was 125 bhp - stock.

That is why it is 125bhp,the oil(89-92 1100k-n)i and water-cooled bikes of the 90's were restricted through the end cans on the 4-2-2 systems. These were restricted by outlet size,with the french(these also have a mechanical restriction,head,etc) and West German(before the wall fell) models being restricted to 100bhp and uk models at 125bhp.The full power models were from the Italian and Canadian market. Martin Bangemann nearly got his Europe wide 100/125bhp limit,but luckily the manufacturers said up yours  
So change your system or fit less restrictive cans.
I have the Perfiormance Bikes write(by TTS) up on the restrictions on the gsxr1100,fzr1000(inlet rubbers) and zzr1100(carb tops).I'll scan it and post it up

Edited June 15, 2016 by Del

[Del]

On 28/05/2016 at 11:20 AM, JezzR said:

As caferacedan mentioned, the exhausts look like a start, don't want to go 4:2:1 as I like the look of the twin exhausts, just something that could improve the flow and sound better. Could anyone recommend any replacements and/or specialists that can help?

The oil and watercooler 1100's use basically the same design 4-2-2 system. On my 1100k i used a  pair of Harpoon cans(they were actually for a fartblade and RC30,this made a 10bhp(124 to 134.8) difference over the stock cans. 

Edited June 15, 2016 by Del

[JezzR]

Thanks so much Del, great photos, a real beauty! So the original stock exhaust is the problem. Read that many changed them for Yoshimura 4:2:1 I assume something to do with back pressure? You stayed with 4:2:2 (but better ones). Is there much performance difference between 4:2:2 and 4:2:1 do you know, looks like you must have had to do some work to get those blade cans to fit?

[spondonturbo]

if you do decide to change your exhaust, I am breaking my WP and have a Remus stainless system with titanium end can 4-2-1. Looking for around £250, but not really sure on value

[Del]

On 15/06/2016 at 11:05 PM, JezzR said:

Thanks so much Del, great photos, a real beauty! So the original stock exhaust is the problem. Read that many changed them for Yoshimura 4:2:1 I assume something to do with back pressure? You stayed with 4:2:2 (but better ones). Is there much performance difference between 4:2:2 and 4:2:1 do you know, looks like you must have had to do some work to get those blade cans to fit?

The Harpoon link pipes were welded to the stock headers and then it went together quite easily  
Gsxr1000k1-4 Titanium headers are also a  good fit and work really well(it made 136 with the 1000k2 headers,CCC 1000k5 link pipe and micron can),.I've gone to a 4-1 micron(will get it on the dyno when it is back together) now

Btw If you want back pressure then stick a potato in your end can,that's back pressure,as the gases cannot go anywhere and so there is a build up of pressure.Backpressure is usually bandied about with powerbands,i.e that exhaust is too short,so there will be no backpressure and you won't beable to hit the powerbands 
http://www.gomog.com/allmorgan/exhaustbackpressure.html

[Kristjan]

I have full Akra 4-2-1 on my 1146W, love it other than that it is very silent mode'ish with stock can length. I haven't been brave enough to chop the can either.

Don't know a flying fuck about my dyno figures, but I have a black power band on it...

K-series stock systems are nowhere near a good fit tbh... They need bending and can still look awkward after they finally fit. Just a perfectionist's opinion

[JezzR]

Cheers everyone, thanks for the link Del. From what I've been able to find out the exhaust systems for the oil coolers won't fit the water coolers, shame as there appears to be more choice for the former.

Kristjan; don't suppose you can remember where you got your Akra from, what year is your bike, any pics?

[oldscool]

I did some research on something called the wheelie wire, didn't believe it until I actually read some convincing post, from a rock solid source, the factory actually installed this to retard the timing, don't know exactly how it works but I do know it exists! This wire runs along side the neutral safety wire down by the kick stand. The wire you're looking for is black w/red stripe, I believe all you do is cut the wire and ene cap it! 

[Fazz711]

Wow 7 years to late LoL 

[Gixer1460]

5 hours ago, Fazz711 said:

Wow 7 years to late LoL 

At least he's / she's / they are trying to contribute and not using this as a cheap Eblag site! An acceptable first post abit a tad late 

[oldscool]

Thanks Gixet1460 for having my back. That post wasn't an answer to a 7 year old question! A lot of GSXr riders were asking about that wire not just from this site, so I figured I would check it out and post my findings, every time I write something one of you guys have some kind of smart ass remark. Aren't we supposed to be helping each other out? Stick to what this should be about and use it properly. Keep your comments to yourself unless it's helpful! 

[TonyGee]

13 minutes ago, oldscool said:

Thanks Gixet1460 for having my back. That post wasn't an answer to a 7 year old question! A lot of GSXr riders were asking about that wire not just from this site, so I figured I would check it out and post my findings, every time I write something one of you guys have some kind of smart ass remark. Aren't we supposed to be helping each other out? Stick to what this should be about and use it properly. Keep your comments to yourself unless it's helpful! 

somebody touched a nerve their !!!!!  "everytime you write something theirs a smart ass remark"  youve only got 2 posts   time to chill out its just a bit of banter. 

[Fazz711]

11 hours ago, oldscool said:

Thanks Gixet1460 for having my back. That post wasn't an answer to a 7 year old question! A lot of GSXr riders were asking about that wire not just from this site, so I figured I would check it out and post my findings, every time I write something one of you guys have some kind of smart ass remark. Aren't we supposed to be helping each other out? Stick to what this should be about and use it properly. Keep your comments to yourself unless it's helpful! 

Not sure why you would resurrect a old post.

Why not just start a new one with your information.

[Wee Man]

@oldscoolRTFR especially no.4 no.16 then you'll be absolutely spiffing.