GS1100 Dyno Results Analysis

[Guest]

Well this really is not about how fast either bike is, but what loss factor to apply in developing a Dyno estimate.

WRT that, I agree that 15% is a good estimate. FWIW, most magazines also use 15% to guesstimate wheel hp of new models (from given factory figures), before actually getting the chance to dyno-test them.

 

[posplayr]

WRT that, I agree that 15% is a good estimate. FWIW, most magazines also use 15% to guesstimate wheel hp of new models (from given factory figures), before actually getting the chance to dyno-test them.

Good to hear; I did not want to be guilty of just propagating a old wives tale.

 

[headsbikesmopars]

MYSUZYQ,

The '83 GS1100 was noticeably stronger than the earlier models just as the '81 was much stronger than the '80 models. The '83 had a much more efficient less restrictive redesigned air box than the previous models, and a VERY good set of cams. The '83 cams were by far the best of the GS1100 series. I have seen over 135 hp using the '83 cams a 4 into 1 , set of 36 cv's form the 1150 and a nice street head with a clean up and a good bowl port much like Jim's . Nothing radical or racy. The '83 was the best of the GS1100 series and the 1150's were a step up from the '83 1100. Suzuki should have used the 36 cv's on the '83 models. JMHO.

Terry

 

[Guest]

MYSUZYQ,

The '83 GS1100 was noticeably stronger than the earlier models just as the '81 was much stronger than the '80 models. The '83 had a much more efficient less restrictive redesigned air box than the previous models, and a VERY good set of cams. The '83 cams were by far the best of the GS1100 series. I have seen over 135 hp using the '83 cams a 4 into 1 , set of 36 cv's form the 1150 and a nice street head with a clean up and a good bowl port much like Jim's . Nothing radical or racy. The '83 was the best of the GS1100 series and the 1150's were a step up from the '83 1100. Suzuki should have used the 36 cv's on the '83 models. JMHO.Terry

Terry, I'm aware of all the differences between the two years...also of all the potential that exists for modding for more hp.
I posted about my riding impressions from putting miles on both bikes, often back to back.....I don't know if I would describe the 3 hp difference at the crank, or the difference in torque as translating to 'noticeably stronger' on the street. Again, this could simply be due to differences in condition/set-up from bike to bike and the fact that mileage on both was vastly dissimilar.
What you posted might be more the case in comparing both bikes straight off the showroom floor, but in the real world, with any mods at all thrown in the mix, all bets are off, IMHO.
I agree that the '83 was the best of the series, but the reason I cited was more the reinforced crank. Also agree with the comment on the 36mm carbs.....FWIW, my '82 simply modded with 36 mm BDST carbs, degreed stock cams and 4X1 Wolf pipe was able to leave the '83, (modded with pods, rejetted stock carbs and 4X1 pipe) in any & all situations.

 

[headsbikesmopars]

Terry, I'm aware of all the differences between the two years...also of all the potential that exists for modding for more hp.
I posted about my riding impressions from putting miles on both bikes, often back to back.....I don't know if I would describe the 3 hp difference at the crank, or the difference in torque as translating to 'noticeably stronger' on the street. Again, this could simply be due to differences in condition/set-up from bike to bike and the fact that mileage on both was vastly dissimilar.
What you posted might be more the case in comparing both bikes straight off the showroom floor, but in the real world, with any mods at all thrown in the mix, all bets are off, IMHO.
I agree that the '83 was the best of the series, but the reason I cited was more the reinforced crank. Also agree with the comment on the 36mm carbs.....FWIW, my '82 simply modded with 36 mm BDST carbs, degreed stock cams and 4X1 Wolf pipe was able to leave the '83, (modded with pods, rejetted stock carbs and 4X1 pipe) in any & all situations.

I don't believe the 3 hp rating between the '83 and earlier models. The cams alone were worth twice that. Suzuki rated Katana 1100 at 111 hp and that was the same engine. In like manor, in 1970 Chevrolet rated the Lt1 at 370 horse in the Corvette and the same engine in the camaro at 360 horse. Also the solid lifter 396 was rated at 425 in the Vette and 375 in the Chevelle , same reason. To not upstage the Corvette. Anyway I guess we will have to agree to disagree on this one.

 

[posplayr]

I don't believe the 3 hp rating between the '83 and earlier models. The cams alone were worth twice that. Suzuki rated Katana 1100 at 111 hp and that was the same engine. In like manor, in 1970 Chevrolet rated the Lt1 at 370 horse in the Corvette and the same engine in the camaro at 360 horse. Also the solid lifter 396 was rated at 425 in the Vette and 375 in the Chevelle , same reason. To not upstage the Corvette. Anyway I guess we will have to agree to disagree on this one.

Terry,
So what are you figuring the true ratings would have been for the following years?

80 1100ET 103 hp?
81 1100EX 105 hp
82 1100EZ 108 hp
83 1100ED/ESD/SD 111 hp
84 1150E 119 hp
85 1150E 124 hp

What is funny is that the CycleWorld tests showed the 81 bike being about as if not faster than the 82 and showing higher dyno numbers.
CW discussion here:

http://www.thegsresources.com/_forum/showpost.php?p=1330545&postcount=10

Jim

 

[Guest]

I don't believe the 3 hp rating between the '83 and earlier models. The cams alone were worth twice that. Suzuki rated Katana 1100 at 111 hp and that was the same engine.

Yes, I was going by the 111 hp published by the factory for both the '83 Kat & ED....and the 108 given for the previous year EZ. I would say the factory ratings for both years (or rather, the hp difference between them) are accurate, esp. if one looks at the negligible difference in hp/torque curves in several magazine actual dyno tests (of both models), and also the very similar performance figures (top speed etc) as tested. Glad you are taking this in the proper spirit.... I'm not trying to be argumentative, as frankly, this is like splitting hairs, as I said earlier.
To Jim's point, I have not ridden any of the earlier rectangular-headlight 1100EX bikes, but my friend who owned the '83 1100E had one of those for a short while that he rode on the street and occasionally dragged. I remember him commenting too, that the bike felt pretty strong, and not as significantly weaker as one would expect, given the almost 10 hp deficit (according to some published specs) to his ED. Don't know what to make of that, as the bike was largely stock.:-k

 

[headsbikesmopars]

Jim,
I feel the '80 was more around 100 hp. That is what the Euro model was rated and I don't think there was any difference between that engine and the us model..except the us model carbs was leaned out compared to the Euro carbs. So..the us '80 model could have been even less than 100, not much but a couple maybe. I feel the other ratings were very close, would'nt argue with the 105 for the '81 or 108 for the '82 it was a good performer and I don't doubt the 111 for the '83 except it might have even a little stronger than that 112-113 would be believeable. The '84 1150 was rated at 119 while the '85 1150 was 124..I feel the 1150 was no more than 10 hp better than the '83 1100. JMHO as always. The '81 bike that was used for the road tests was no doubt a 'ringer' most '81's I have seen at the drag strip and on the street would run with the '82 models but not the '83's. Most of the '81's were in the upper 11's , 11.80 range. I rode a friends '82 GS1100 down the strip once (only time I was on it) and went 11.74 with my 210lbs. my '81 all stock went a best 11.78 but was 11.83 just about every time out. A friends '83 would do 11.60 range and a '85 1150 (same guy that had the '82) would do 11.50 all stock. We were at elavation too so the times would have been better at a low elavation or better yet sea level. But the comparo to the ET's with the different model years was interesting. This was back in the mid eighty's...great times they were. Another thing,. no matter what the mags would print the GS1100's were KING at the strip. until the GSXR's came out. Blew off many V maxes and those Honda Magna's they were easy. Leaving the line I would NEVER see them again until coming down the return road to the pits. LOL, I miss those days. VERY good topic indeed. Thanks.

Terry

 

[headsbikesmopars]

Oh, just as a side note, I also had a '73 Kawaski H2 750 that I ran at the strip. I Raised the Exhaust port 4 mm amd machined the intake side of the piston (skirt) 4 mm ,raised the transfer ports 2 mm and that is all along with a set of Gast race chambers and a set of 34 mm mikuni power jet carbs. I built the wheelie bars. That bike ended up going 10.50 !! with me on it..with no air shifter. That bike was alot of fun. I know 10.50 isn't a world beating time but for back in the day and so little work to a 750..well it was a great little bike to try to stay on. Had to be an acrobat to ride it, LOL. Just wanted to share this memory..that bike is in Finland now.

Terry

 

[posplayr]

Jim,
I feel the '80 was more around 100 hp. That is what the Euro model was rated and I don't think there was any difference between that engine and the us model..except the us model carbs was leaned out compared to the Euro carbs. So..the us '80 model could have been even less than 100, not much but a couple maybe. I feel the other ratings were very close, would'nt argue with the 105 for the '81 or 108 for the '82 it was a good performer and I don't doubt the 111 for the '83 except it might have even a little stronger than that 112-113 would be believeable. The '84 1150 was rated at 119 while the '85 1150 was 124..I feel the 1150 was no more than 10 hp better than the '83 1100. JMHO as always. The '81 bike that was used for the road tests was no doubt a 'ringer' most '81's I have seen at the drag strip and on the street would run with the '82 models but not the '83's. Most of the '81's were in the upper 11's , 11.80 range. I rode a friends '82 GS1100 down the strip once (only time I was on it) and went 11.74 with my 210lbs. my '81 all stock went a best 11.78 but was 11.83 just about every time out. A friends '83 would do 11.60 range and a '85 1150 (same guy that had the '82) would do 11.50 all stock. We were at elavation too so the times would have been better at a low elavation or better yet sea level. But the comparo to the ET's with the different model years was interesting. This was back in the mid eighty's...great times they were. Another thing,. no matter what the mags would print the GS1100's were KING at the strip. until the GSXR's came out. Blew off many V maxes and those Honda Magna's they were easy. Leaving the line I would NEVER see them again until coming down the return road to the pits. LOL, I miss those days. VERY good topic indeed. Thanks.

Terry

Thanks Terry
I'll see if I can make a little more sense out of the data.
Jim

 

[Bad Kaw]

Fun discussion to read, guys. Please keep posting away.

 

[Guest]

At this point, it's probably all been said, except perhaps to mention that several members here have posted the actual dyno results of their '82 & '83 1100E bikes, and all have fallen within a small 2 hp window (92 to 94 hp) at the wheel, IIRC. I don't think anyone has posted figures for the earlier '80 & '81 bikes, unfortunately.

 

[Bad Kaw]

What about 1150s?
Additionally, having worked in two different shops with dynos, do you account for dyno reading variances?...or are the readings close enough?

 

[Guest]

There is variation for sure....a point made earlier in the thread. From reading several tests/reviews of the time, it appears that most of the American bike magazines in the early eighties tested on the same machine though (the Kerker dyno in California) which helps narrow their findings, somewhat.:-k

 

[Bad Kaw]

Hmmm; that's pretty interesting.
What about 1150 numbers? And what about with K&Ns, jet kit, and pipe? I ask b/c that's the set-up that I have. I should have dynoed it before I swapped to GSXR wheels and the 530 chain/sprockets so I could make an accurate comparison.

 

[Guest]

Hmmm; that's pretty interesting.
What about 1150 numbers? And what about with K&Ns, jet kit, and pipe? I ask b/c that's the set-up that I have. I should have dynoed it before I swapped to GSXR wheels and the 530 chain/sprockets so I could make an accurate comparison.

Sorry, not really familiar with the 1150. I recall hearing a few times, that they put out a little over 100 hp at the wheel, but I don't know if this is in fact hearsay, or heresy. If someone here has the Motorcycle Reports compilation of tests/reviews (from virtually every N. American magazine, back in the day) for the 1150, they might be able to share that info. It might even be worth springing for, depending on your level of interest.

 

[headsbikesmopars]

Don't know anything about the 1150 ?? Just THE best all around standard ever made. I have seen 119 at the rear wheel on a stocker that was rated at 124 at the output shaft. Under rated for sure..

 

[Guest]

I have seen 119 at the rear wheel on a stocker that was rated at 124 at the output shaft. Under rated for sure..

One of several logical conclusions, yes. No doubt they are much stronger performers, but I'm partial to the 1100 styling myself...to each his own, eh?

 

[headsbikesmopars]

One of several logical conclusions, yes. No doubt they are much stronger performers, but I'm partial to the 1100 styling myself...to each his own, eh?

I like them too that is why I have three GS1100's. 1980, 1981 and a nice 1983 ..glad you like them too...

 

[rapidray]

I did an 1166 83 1100 motor for a friend that made 139.8 at the rear wheel with .348 cams & 36 RSs. All used parts & a stock valve job. (He ran out of money for head work!) It has run 9.30 at 146 with a slick & wheelie bar. 10.25 to 1 compression street motor that I wouldn't HESITATE to ride across country with! Ray.