CPI pipe -where are the conclusive results?

[speedway501]

They were different bikes on different days as well.

[MojoScojo]

Ran a bone stock CR500 with a CPI pipe and Pro Circuit 304 silencer on the dyno. It made 58.4 rear wheel hp. Advanced the timing about 2 degrees and increased jet size from 170 to 172. A stock standard CR500 with standard pipe on the same dyno ran 51hp (not the same bike). Both engines were fresh. The Dyno is a Dynamics brand.

same thing i said 3-4 months ago with seat of the pants dyno. everyone laughed it off as bullshit. suckers

[M.F.D.B.]

cams were degeed, balancers were marked correct, everything, same ignition ran on both

And?

[MojoScojo]

cams were degeed, balancers were marked correct, everything, same ignition ran on both

And?

1 liked 37 degrees, one 31 i think

[100hp honda]

Ran a bone stock CR500 with a CPI pipe and Pro Circuit 304 silencer on the dyno. It made 58.4 rear wheel hp. Advanced the timing about 2 degrees and increased jet size from 170 to 172. A stock standard CR500 with standard pipe on the same dyno ran 51hp (not the same bike). Both engines were fresh. The Dyno is a Dynamics brand.

same thing i said 3-4 months ago with seat of the pants dyno. everyone laughed it off as bullshit. suckers

problem is you clowns have used fmf your entire lives and cant image something out there is better, so you critisize and laugh.

[M.F.D.B.]

cams were degeed, balancers were marked correct, everything, same ignition ran on both

And?

1 liked 37 degrees, one 31 i think

yeah but what were the dyno #'s? Timing has a lot of veriables:

Spark plugs arnt perfect.
Were the plugs indexed?
Where the combustion chambers CNC matched? polished?
Spark plug wires the same? etc. etc.

I agree with others on the dyno part, it has to be the same motor, same day and exhaust gas analyzer tuned (fuel/air) in between each changed of exhaust...

[MojoScojo]

same thing i said 3-4 months ago with seat of the pants dyno. everyone laughed it off as bullshit. suckers

problem is you clowns have used fmf your entire lives and cant image something out there is better, so you critisize and laugh.

Really? Personally, I have zero problems accepting that CPI may be a better pipe for blah blah application. I honestly don't even care. My only problem with your statement is your choice of "proof". 2 completely different engines being dyno'ed. Means absolutely nothing. Thus, .

[MojoScojo]

yeah but what were the dyno #'s? Timing has a lot of veriables:

Spark plugs arnt perfect.
Were the plugs indexed?
Where the combustion chambers CNC matched? polished?
Spark plug wires the same? etc. etc.

I agree with others on the dyno part, it has to be the same motor, same day and exhaust gas analyzer tuned (fuel/air) in between each changed of exhaust...

Ah. Understood.

[100hp honda]

problem is you clowns have used fmf your entire lives and cant image something out there is better, so you critisize and laugh.

Really? Personally, I have zero problems accepting that CPI may be a better pipe for blah blah application. I honestly don't even care. My only problem with your statement is your choice of "proof". 2 completely different engines being dyno'ed. Means absolutely nothing. Thus, .

look man ill spell it out one more time, since you missed it the first time i explained it 3-4 months ago. i had a fmf pipe on my bike, without doing any changes what so ever i put the cpi on, ( i didnt even change jetting ). instant power increase. felt like 8hp just like they claim, in reality maybe it was only 6, i dont know because i didnt dyno the difference but it was a significant amount. i was simply agreeing with the other guys statement of the 7hp gain. cpi kicks the shit out of any other pipe avalable to the normal person, including the gss.... no offense glen. if a guy wanted to get real crazy he probly could have matt shearer or mike at cpi build a better performing pipe than the current cpi but it would be a mother fucker to make fit in the chassis or possibly impossible to make it fit into the chassis. if the pipe wont fit in the chassis, nobody would buy it, cpi took that into consideration and built the best they could while still making it appeal to the average guy. everything clear now ? .

[Roostius_Maximus]

same sparkplugs, same wires, same distributor, same fuel pump, checked with the same carbs, same headers, same intakes, and same conditions

[AlisoBob]

Did engine #2 have a S/H ignition on it??

[M.F.D.B.]

Did engine #2 have a S/H ignition on it??

[M.F.D.B.]

same sparkplugs, same wires, same distributor, same fuel pump, checked with the same carbs, same headers, same intakes, and same conditions

With around 14lb ft. more on one motor I bet its either a better casting of the heads or misalignment with the gaskets. I think you guys should swap around the EGT probes to see if the big variation in EGT is the probes or is a result of unbalanced fuel/air mix to the cylinders. I bet if you swapped the heads the dyno numbers would switch too..

[Roostius_Maximus]

ya, i doubt the heads were the issue, they were checkd, block was decked, intakes were machined to match, the gasket is never an issue, cometics on both. we even adjuted the rockers again to make sure something wasnt goofed

[M.F.D.B.]

ya, i doubt the heads were the issue, they were checkd, block was decked, intakes were machined to match, the gasket is never an issue, cometics on both. we even adjuted the rockers again to make sure something wasnt goofed

You would be surprised how much variation in port dimension you can get from "core shift". Did you "cc" the ports on both heads? I bet you will see a wide variation unless the heads have been ported and flow matched...

[Roostius_Maximus]

dont woory, we didnt index the plugs either

[AlisoBob]

You would be surprised how much variation in port dimension you can get from "core shift". Did you "cc" the ports on both heads? I bet you will see a wide variation unless the heads have been ported and flow matched...

This isnt a 1954 Edsel were talking about is it?

[M.F.D.B.]

dont woory, we didnt index the plugs either

[M.F.D.B.]

This isnt a 1954 Edsel were talking about is it?

[Roostius_Maximus]

torque killer!
very peaky, takes the power 1000rpm higher, and after that did add 5.5hp, BUT the torque was down everywhere!
with no silencer we lost 18ftlbs from what the fatty had done and gained 4hp, with the silencer we only lost 3ftlbs but gained 5.5hp, it was still 1000rpm later.
at 10000 the cpi made 2hp more than my fatty at 10000

I'm officially NOT a CPI guy

FATTY!

btw, this engine i put in sunday made 1hp more than my friday engine, but gained 7ftlbs of torqure, moved the delivery of both down 1000rpm, made it pull unbelievably smooth, extended the over rev from 8500 to 10000, and is good on fuel if my 5.5 hours of riding had anything to say.
The TTM bike from Team DNS will be running this porting.

[Roostius_Maximus]

the 39pwk made2hp more than the 41 right from the bottom, but the torque curve was 2-3 higher and wider with the 41, both peaking within .1 of eachother. They were both looking for the same jet, we couldnt do anything but take power away by messing with where i have it.

I foolishly didnt try the pc pr gnarly, but that'll be coming. I'm going to run my 86 engined '88 withthe gold series, bored pj, carbontech reed. the 2000 thats epoxy modded in the transfers,gnarly +vf2+bored pj, and the 1999 that bro rides thats stock with a pc pipe and shortened pc silencer. sometime in the next week or 2

[hoofarted]

Good to hear the final result. Guess thats why its a dunes pipe.

I'm +1 on the Fatty as well. That coupled with 250 ignition = good times!

[Roostius_Maximus]

stock port timing, stock port dimensions at the sleeve, both engines setup to achieve 0 deck, stock reeds, stock boot(blended to fit the 41carb) 88 250 ignition, fmf fatty pipe, fmf silencer. the green dyno is fridays engine, its an 87 based crankcase and a 89+jug with the sleeve cut down to fit the older cases. both have identical machined exhasut ports.

[Roostius_Maximus]

I wasnt chasing the biggest HP with this porting, looking for torque and to move it down in the rpm, did it, and the delivery is smooth like my 03 250, it doesnt rant, it doesnt give the big pipe shutter then start working, it yanks on you from everywhere

[Roostius_Maximus]

temp was 18c friday when i tested, 28c lastnight