I'm an airbox believer

[Nessism]

I’ve posted this chart before only to have all the pod and header lovers come out of the woodwork lambasting it saying the intake system was “not optimized” for use with a header. No doubt this is true but this data, which was assembled by respected UJM guru Joe Minton, clearly shows that power gains are not as dramatic as many people claim. Take off the airbox instead of just removing the lid, install pods and rejet appropriately, and there most likely is a few more hp available. No way you are going to get more than say a 10% boost over stock though, and no way that would result in taking .8 – 1.0 seconds off the bikes ¼ mile time.

[blowerbike]

you have to figare in the lastest and greatest ST.3 jetkit.
you have to figare in the weight reduction from the exhaust.
20-25lbs is worth 1 tenth of a second plus the motorcycle reacts quicker.
you have to figare in that the motorcycle will 60' better.
what you pick up in 60' is more than that at the end of the traps.(if you pick up a tenth you will gain near 2 tenths give or take a couple hundredths).
if you haven't tuned and drag raced one these bikes or drag raced more than a couple times....you dont know for sure.
the graph you listed shows numbers from 25 years ago that mean something but dont tell the whole story today.
race a lean bike on a good day and it will perform badly.
race the same bike on the same day with a pipe and st.3 jetkit and you will see a major improvement.
i stand by my origanal statement earlier in this thread.
.8-1.0 of a second reduction is possible with a GS1100/1150 16v..

[Nessism]

I can accept that a drag racer could take a low performing stock sample, install a race header, pods/velocity stacks, jet kit, tweak the ignition timing to work with high octane fuel, tweak the cam timing, and in the end they could take a goodly bunch of tenths off the ¼ time. I seriously doubt Joe Lunchpail could achieve the same results though by installing a street header, pods and a DJ3 kit.

[blowerbike]

I can accept that a drag racer could take a low performing stock sample, install a race header, pods/velocity stacks, jet kit, tweak the ignition timing to work with high octane fuel, tweak the cam timing, and in the end they could take a goodly bunch of tenths off the ¼ time. I seriously doubt Joe Lunchpail could achieve the same results though by installing a street header, pods and a DJ3 kit.

lol,
i didnt know Joe was a member here

[rapidray]

There are also BIG differences between us "Tuners" here & the "Bolt On Specialists" that seem to not be able to figure out how to tune their bikes. There is a HUGE difference in Knowing what you're doing and Guessing! I am a member at another site where a LOT of people have problems tuning a specific model bike with pods vs airbox & I have NO problems with that same bike because I've done at least 20 of them & know what to do. The pipe comparison is NOT a good example because they were ALL tuned the same way instead of for each SPECIFIC exhaust! Tune EACH pipe optimumly & I GUARANTEE the results would be different than what Minton posted! Minton knows that too so it was an apples to oranges comparison instead of an HONEST evaluation of each system's potential! Ray.

[49er]

There are also BIG differences between us "Tuners" here & the "Bolt On Specialists" that seem to not be able to figure out how to tune their bikes. There is a HUGE difference in Knowing what you're doing and Guessing! I am a member at another site where a LOT of people have problems tuning a specific model bike with pods vs airbox & I have NO problems with that same bike because I've done at least 20 of them & know what to do. The pipe comparison is NOT a good example because they were ALL tuned the same way instead of for each SPECIFIC exhaust! Tune EACH pipe optimumly & I GUARANTEE the results would be different than what Minton posted! Minton knows that too so it was an apples to oranges comparison instead of an HONEST evaluation of each system's potential! Ray.

Valid points Ray. To compare apples with apples would take a huge amount of dyno time, but that's the only accurate way of making valid comparisions. Different pipes require different jetting to optimise performance, so using the same spec carb tuning for all, will not be a true gauge of their full potential.

I agree that Joe blow doesn't have the experience to achieve these optima, nor the dollars to endlessly pursue that elusive last HP.

I tend to align with Nessism though. It's very difficult for the average DIY tuner to get anywhere near a 1 second gain in performance. For some, if they gain over 1/2 second, they'll relay their results verbally as knocking off 1 sec (rounding it up). I've even had the experience of being given the incorrect timing card at a drag meet which would have made my time 1/2 sec quicker than my true time. With computerised timing, that should'nt happen now.

At the end of the day, if you throw enough dollars at it, you can make additional gains that the average tuner never gets to know/hear about.

[srsupertrap]

Some Dated Figures

No way pods, pipe and jetting will take a full second off a GS bikes 1/4 mile time. You'd be luck to get 1/2 second.

Here are some stock GS1000 1/4 mile numbers as I recall:

Cycle Mag 1978 GS1000C 11.89 @ 113.35
Cycle Mag 1979 GS1000EN 12.44 @ 108.43

Here is the link to the Motorcyclist Dec 1984 Project GS1000 article written by, you guessed it Joe Minton. Here is some of the mods he/they did for this project:

1) Yoshimura 1085 kit CR 11.2:1 (Fairly high for street)
2) VHR "Set up" Mikuni VM29's Smoothbore w K&N's
3) Vance & Hines 4 into 1
4) Dyna S Ignition
5) KV Coils & Wires
5) Degreed Cams 104/106
6) Metzeler ME99 Rear

Resulting 1/4 time on "an extremely slippery dragstrip": 11.72 @ 119
Top Gear roll on after 200 yards: 85.0 mph (This number is equivalent to a 1984 Yamaha FJ1100 but less than 1984/85 GS1150)

This may not settle anything because Joe Minton's comment about the airbox was, "The GS1000 airbox is restrictive and should be replaced if you want to get the most out of your engine" I would GUESS a top speed in the range of 119-122 mph translates into low 11 or high 10 sec ET under ideal conditions.

http://www.mediafire.com/download.php?0zwjtwfzbft

[KEITH KRAUSE]

I can accept that a drag racer could take a low performing stock sample, install a race header, pods/velocity stacks, jet kit, tweak the ignition timing to work with high octane fuel, tweak the cam timing, and in the end they could take a goodly bunch of tenths off the ¼ time. I seriously doubt Joe Lunchpail could achieve the same results though by installing a street header, pods and a DJ3 kit.

Ed, sorry if I struck a nerve by saying what I believe.
If I'm wrong, fine. If I'm not, fine. Not that big a deal.
That chart is pretty much useless in this case. And factoring in the tuning abilities of the owner just adds more uncertainty. And the Motorcyclist magazine project bike test would only matter if Peewee Gleason himself ran the project bike and a stocker at the same time. He'd also have to lose the 1085 kit and the 29's.
I copied the project bike except for the 29's. Many years ago I had a quick run against a 1000 with my mods and the 29's. Only other difference was the other rider was a good 20 lbs lighter. We only went through the first 3 gears but he easily jumped in front. I was impressed and my ego hurt a bit. It seemed like we had similar skills so I believe the 29's were the difference. I believe the project bike would be a little quicker than just 1 second over a stocker if tested by the same rider and under the same conditions. So the Motorcyclist times are useless too for proving anything.

[skip]

thought i would add some gas to the fire. My own experience . stock 1985 GS1150 these numbers are from my memories I did not save all my time slips way back then. 11.0 something at 122 something. Next the same GS with Vance and Hines megaphone, Fours and More jet kit, k&n filters and Dyna coils for about 10.85 @ 124ish. Up next came 38 flat slides and the ET dropped to 10.75 and the mph only went up two to about 126 . Then came the rest of the puzzle that put it all together. 1229 kit, mild street porting, cam motion g4 cams, and Dyna S ignition. Now the whole package worked and the ET fell into the 10.45 range with a best of 10.36 @ 134 I was not inexperienced at drag racing and had many runs under my belt before the 1150 ever saw the track. The bike ran with no wheelie bars and the stock swing arm and 130 bias tire. all those mods and I still did not see a full second increase! It was not till I added nitrous that i saw a full second increase over stock in the 1/4 . Now granted my bike was limited due to the stock tire size and stock swing arm. But for what its worth I have never seen anyone pick up a full second with just bolt on performance enhancers discounting a turbo, supercharger or nitrous.

[49er]

thought i would add some gas to the fire. My own experience . stock 1985 GS1150 these numbers are from my memories I did not save all my time slips way back then. 11.0 something at 122 something. Next the same GS with Vance and Hines megaphone, Fours and More jet kit, k&n filters and Dyna coils for about 10.85 @ 124ish. Up next came 38 flat slides and the ET dropped to 10.75 and the mph only went up two to about 126 . Then came the rest of the puzzle that put it all together. 1229 kit, mild street porting, cam motion g4 cams, and Dyna S ignition. Now the whole package worked and the ET fell into the 10.45 range with a best of 10.36 @ 134 I was not inexperienced at drag racing and had many runs under my belt before the 1150 ever saw the track. The bike ran with no wheelie bars and the stock swing arm and 130 bias tire. all those mods and I still did not see a full second increase! It was not till I added nitrous that i saw a full second increase over stock in the 1/4 . Now granted my bike was limited due to the stock tire size and stock swing arm. But for what its worth I have never seen anyone pick up a full second with just bolt on performance enhancers discounting a turbo, supercharger or nitrous.

Thanks Skip. Nice to get some quantitative evidence.

There will be those out there who will say that Suzuki went a little over the top with their stock 1150 cams for road use anyway. Perhaps if they were more user friendly, it would have been possible to better the stock 1/4 time by a full second with bolt on mods. I doubt that too from my personal experience on the strip. Talk is cheap when it comes to times and HP!!!!

[KEITH KRAUSE]

Skip, the info is fine but I originally posted about a typical 2 valve 70's GS1000 and how I think a quality pipe/pods effect the performance. The factory made significant advances in the stock airboxes in general from '78 to '85. Also for the header in general. 4 valves per cylinder helped.
The factory addressed flow much better in the 80's and the same intake/exhaust mods produced less significant flow change by changing to pipe/pods. As time went by, such as into the 90's, installing pods could actually lower the performance because the stock airboxes were well designed. Same to some degree for the headers.

[blowerbike]

ran 10.40's w/ drop in cams and radial slides..16t front sprocket..no air shifter ect..head had never been off.
added 3" over arm..dropped to a 14t front sprocket..
dialed a 10.33 at muncie dash for cash with out any time runs on new set-up.
broke out with a 10.30 flat.
dead stock 85 1150E/drop ins and 3 over arm..thats it unless you count the front sprocket..no ignition/no coils/no shift light and a metzler ME88 150/70 tire and stock E model handlebars(you don't have to have low bars to go fast.
this was also with a dual exhaust..no 4into1 stuff happening.
does anyone have a guess the pipe i was running?
if i had the money back then...i would have had a ported head and piston kit.
back then i had plenty of time and not much money..you get the most and more out of what you have to work with.
it all depends on who's riding and who's doing the work..
if no one here has ever spent a couple decades of there life doing this stuff at the track...dont read and assume a things...
case if fact..
read all the questions asked on this board that alot of the times are self explanatory.
and for the record...
a set of 36mm radial slides are worth 3 solid tenths on the same night/ same bike/ same rider/ verses jet kitted CV 1150 carbs on a 1150 Suzuki.
any comments?
i'm all ears.

[rapidray]

Heck Terry, 33 ROUND slides were worth 3 tenths on my blue 85 1150E model! Ray.

[blowerbike]

Heck Terry, 33 ROUND slides were worth 3 tenths on my blue 85 1150E model! Ray.

when i was doing this stuff i posted...
i think you was riding a fire breathing 700 at the time
just messin with you raymond

[mixongw]

Speaking of esthetics, purely. I want to add a Hypercharger to each side of my air box. Too expensive just for the look.