Keeping current

[DetonatorTuningSolutions]

Hi,

GEBE is actually selling and shipping stuff daily, it's just that they have stopped taking new orders while they catch up with the back orders.

the GEBE system is good provided you use one of the recomended engines. (read not over 40cc ). running a really high powered engine like mine takes alot of attention.

the GEBE is THE choice if you want light weight, smooth and quiet operation and the ability to use any number of very high quality engines.

there are other rack mount systems that use chain drive, there are subjective advantages to both. if you are capable of building your own support rack you could use the GEBE drive and run a jackshaft with 4 sprockets and 2 chains.

i have a complete low mileage (2.5 months use ) GEBE mount kit W/O engine for sale. look in the swap shop. it has the large clutch mounting plate and a complete rear wheel.

steve

 

[DetonatorTuningSolutions]

here's a new twist, i'm going to a Staton inside drive w/ my GP460 and have some fitment problems i need to address.

i'm hoping someone can tell me what effect shortening the first segment( W/ the mount flange ) by 1/2" will have on the characteristics of my DDM Dominator tuned expansion chamber pipe.

will this make some area stronger or softer, or move the main power band higher or lower in the rpm range ?

you can see pics of the pipe in the TREK 4500 / GEBE w/ GP460 thread in this forum.

thanks

 

[lennyharp]

The gear box should be bullet proof but mount solid and watch chain stretch. The gear box is probably good at least to 10 HP so you will not be taxing it too much but a little more than the Subaru EHO35 and other stuff usually put on. I look forward to seeing what you come up with for a final bike. A daily commute is the ultimate test for these machines as you need them dependable and ready to go when you are tired from a days work. And then the same day after day.

 

[DetonatorTuningSolutions]

The gear box should be bullet proof but mount solid and watch chain stretch. The gear box is probably good at least to 10 HP so you will not be taxing it too much but a little more than the Subaru EHO35 and other stuff usually put on. I look forward to seeing what you come up with for a final bike. A daily commute is the ultimate test for these machines as you need them dependable and ready to go when you are tired from a days work. And then the same day after day.

oh my lands Lenny !!

what are you thinking telling me that the box will likely handle 10HP ? (which by the way i think is probably conservative )

do you realize that the big Franco Morini air cooled engine is 9.8HP and has a centrif. clutch ?

OH !! my fingers are tingling and my toes are itching, i better get a good bonus this year !! i need to lay down.

steve

 

[DetonatorTuningSolutions]

well i got some info about altering my pipe and decided to make some dents in it to form the needed clearance.

this was a compromise of risk against cost. i could have cut a section of the pipe 1/2" to raise the expansion chamber, then bought a spacer known as a X-port to move the whole pipe out further from the engine to regain the expected loss of topend power. but that takes time and more money soooo...

i worked some dents into the lower approach throat of the chamber and the lower rear reduction taper of the chamber itself. there was a 50/50 chance of ruining the pipe AND messing up the power bands of the engine.

turns out i lost a VERY little low end and GAINED midrange -topend HUGELY. so it's a win / win this time.

more later,
steve

 

[lennyharp]

That is almost a magical part of motor tuning. I don't really understand what makes it work.

 

[DetonatorTuningSolutions]

yes Lenny, it was a total risk "all in or no-thin" deal. i had heard of guys denting expansion chambers before and having good results, but the articles also said they had access to alot of salvage pipes and that they ruined most of them before they landed on the locations and sizes that worked.

i was and am pretty confident that reducing the cross section of the "throat area" wouldn't cause trouble from my motorcycle intake port experience the gas is traveling along the "roof" of the pipe in that area and raising the "floor" increases the velocity of it's passing.

the big dent in the reduction taper was the "step of faith", i knew that was going to have a big effect somewhere and justified it solely on the possibilty of it being good.

i rode it to work this morning and have to revise my early evaluation. due to being tentitive and uncertain of the outcome i guess i was holding back some on the bottom. this morning i was just letting it run and don't think it gave up anything in the bottom 1/3. the upper 2/3 is simply amazing esp. the 35-55mph range. and it's not just how fast it accel's through that range, it's torquey strong there too now. on the few hill on my ride where i was giving up rpms and 1-2 mph before i actually was able to pick up speed this morning.

i'll only be happier when someone buys my GEBE setup. i posted a new price by the way.

steve

 

[DetonatorTuningSolutions]

just so you know, as i have explained on the other forum, this pipe mod was a BAD idea and ended up causing a over lean condition to occure in the upper 1/3 of the rpm band and i burnt a hole thru my piston and ruined my cylinder.

i should have taken the time to cut the pipe apart and reweld it.

live and learn.

steve