Af18 zx50 corsa build. Is my pipe holding me back?

[mantrans]

Hi, I will try to keep it short and sweet. I cant find a direct answer to my concerns using the search so I am sorry if this is redundant.

lightly ported corsa by me, Block port matched
Malossi full circle race crank
PG long pipe matched to port
Stage 6 intake also matched
Malossi variator 5.5-6 g roller mix( 5 and 5.5 sliders on the way)
Polini 3g clutch stiffest springs on stiffest settings( about 8K) Red 35% center spring.
malossi 16x42 primaries
NCY coil
I switch between two fuels I have on hand, vp110 and just tried x16 and I sparingly use my Q16 ( highly oxegenated and comes out to a true 116 octane, pretty nice as I can go up 4% in fuel and it does make more power. on the 110 and x16 I run a 128 main, screw 3 turns out and needle on third clip. 70.86mph and only thing to race is my buddies true 92cc stroker gy6 15:1 compression on nitrous and I really pull past him about 40mph, off nitrous i pull him around 30mph. The Revs pick up to about 8100 on take off so I feel like that is close enough to the band to start doing something earlier on.

Here is my question. I have enough in me for one quick mod. I dont want to risk going ministroker and have a issue this close to this bike ride we are doing so I am looking at pipes. THis may sound stupid but is there a basic rule of thumb for pipes like mine vs a chambered pipe such as the c16 or polini? I want to gain a good bit on take off and not lose top end, it really drives me nuts accelerating like a stock scooter. 35mph and getting in it is sweet, I would just like it to get wild around 10-15 mph. Would any of you recommend the Polini race pipe, as that is what I am looking at .. Thanks.

[Meloshameless]

I have 2 elites, one with the c16 and other with the arrow. Both pull really hard. Ive also heard the polini pipe in action on g9's bike in person. Its sounds animal! I had really stiff clutch springs maxed and realized i was just wasting alot of low rpms cuz the beginning of my band was right around 7-8k. I switched to the polini yellows and it got up quicker and pulls the wheel up every time. You might also wanna try dropping down to the yellow contra. That red might be holding you down in a lower gear when u could be going faster sooner.

[ped]

screw 3 turns out, may be too much. 2 1/2 max I think? also, needle on third clip? from the top? what type of carb?
PG long will not REV high as C16, Arrow. or polini. Talk to graphit9. he know's how high it will Rev. he tested on a dyno. GL.

[Rip_City_Spree]

After running my Corsa with a long and getting to 70 no porting nothing. And only hitting 10k in Rpms maybe 3 times. That's about all that pipe is gonna get. Your losing about 2-3k in Rpms compared with the yasuni or polini pipe. so yes in my opinion the pipe can be limiting the potential of the Corsa which after switching to a milder bbk made me realize how much of a beast it is.

[bonesv]

Change spring +1. Roller weights - add +1. Drop pilot jet +1.

[mantrans]

I have 2 elites, one with the c16 and other with the arrow. Both pull really hard. Ive also heard the polini pipe in action on g9's bike in person. Its sounds animal! I had really stiff clutch springs maxed and realized i was just wasting alot of low rpms cuz the beginning of my band was right around 7-8k. I switched to the polini yellows and it got up quicker and pulls the wheel up every time. You might also wanna try dropping down to the yellow contra. That red might be holding you down in a lower gear when u could be going faster sooner.

That is a really good point, I thought the Pg had a higher power band so I tried to stall the transmission to take advantage of that, but maybe it was an illusion and I went overkill on the tranny... However I ordered the polini race pipe. Thanks!

[mantrans]

screw 3 turns out, may be too much. 2 1/2 max I think? also, needle on third clip? from the top? what type of carb?
PG long will not REV high as C16, Arrow. or polini. Talk to graphit9. he know's how high it will Rev. he tested on a dyno. GL.

Yeah 3rd from top, it was on the 4th because it would "cut out" cruising at partial throttle, then once the motor broke in it started to need a bigger jet so then i needed to revert back to 3rd clip. My friend is pretty good also, he is much better at the tuning aspect and he listens as he plays with the screw and it sounded dead on.. i have to change all my settings back and forth depending on fuel. Carb is a 24mm polini evolution with MJ at 126 on the x16 race fuel and 132 on the oxy q16 fuel. Thanks, I talked to him and got the polini race pipe as the c16 was out of stock.

[mantrans]

Change spring +1. Roller weights - add +1. Drop pilot jet +1.

Sorry, I didnt understand your or the lingo on this one. are you talking Percent? I am 130lbs which may or may not change your answer. I was 171 and lifting weights in november and got sick so im down to 130 now..yikes. Also I went from 3x5.5 gram and 3x6.0 gram rollers to 3x6.0 and 3x6.5 rollers and it was sluggish.. also went down to 3x5.0 and 3x4.5 and it sounded like a 4 stroke on the rev limiter until 40mph then finally started moving. I do not have any extra pilot jets... it seemed as the one included worked fine.. then again I was a 4 wheeler dirkbike guy so maybe it makes a difference on these. thanks!

[mantrans]

I have 2 elites, one with the c16 and other with the arrow. Both pull really hard. Ive also heard the polini pipe in action on g9's bike in person. Its sounds animal! I had really stiff clutch springs maxed and realized i was just wasting alot of low rpms cuz the beginning of my band was right around 7-8k. I switched to the polini yellows and it got up quicker and pulls the wheel up every time. You might also wanna try dropping down to the yellow contra. That red might be holding you down in a lower gear when u could be going faster sooner.

Also, is there a video of his bike with the corsa pipe? I cant wait for mine to come in so I want to hear it lol

[Rip_City_Spree]

Have heard the polini in person and it sounds great looks great and is great quality. With your Corsa you should see a big difference.

[bonesv]

Change spring +1. Roller weights - add +1. Drop pilot jet +1.

Sorry, I didnt understand your or the lingo on this one. are you talking Percent? I am 130lbs which may or may not change your answer. I was 171 and lifting weights in november and got sick so im down to 130 now..yikes. Also I went from 3x5.5 gram and 3x6.0 gram rollers to 3x6.0 and 3x6.5 rollers and it was sluggish.. also went down to 3x5.0 and 3x4.5 and it sounded like a 4 stroke on the rev limiter until 40mph then finally started moving. I do not have any extra pilot jets... it seemed as the one included worked fine.. then again I was a 4 wheeler dirkbike guy so maybe it makes a difference on these. thanks!

Oh, forgive me. I was just agreeing with the previous answers given. But after reading your description on your last post, I don't know what to suggest. For sure I would get rid of that heavy torque spring to something around 1500 rpm over stock (15%)?, then ride to see where it is at with the take-off and if need, increase the roller weight then see how it is. Watch the temps/or read spark plug for correct jetting but see if you can get a few smaller size jets to work with, maybe one size larger also. Welcome to tuning! If you change the pipe, you will possibly have to adjust again.

[mantrans]

Change spring +1. Roller weights - add +1. Drop pilot jet +1.

Sorry, I didnt understand your or the lingo on this one. are you talking Percent? I am 130lbs which may or may not change your answer. I was 171 and lifting weights in november and got sick so im down to 130 now..yikes. Also I went from 3x5.5 gram and 3x6.0 gram rollers to 3x6.0 and 3x6.5 rollers and it was sluggish.. also went down to 3x5.0 and 3x4.5 and it sounded like a 4 stroke on the rev limiter until 40mph then finally started moving. I do not have any extra pilot jets... it seemed as the one included worked fine.. then again I was a 4 wheeler dirkbike guy so maybe it makes a difference on these. thanks!

Oh, forgive me. I was just agreeing with the previous answers given. But after reading your description on your last post, I don't know what to suggest. For sure I would get rid of that heavy torque spring to something around 1500 rpm over stock (15%)?, then ride to see where it is at with the take-off and if need, increase the roller weight then see how it is. Watch the temps/or read spark plug for correct jetting but see if you can get a few smaller size jets to work with, maybe one size larger also. Welcome to tuning! If you change the pipe, you will possibly have to adjust again.

Thanks that all makes sense, I have the plastics off to paint them while I wait on the pipe so it wont be ridden until it gets here ( no sense in trying to refit that Pg long if its coming back off i guess). When the pipe gets here I will be sure to write a detailed review... once dialed it.

[mantrans]

I have 2 elites, one with the c16 and other with the arrow. Both pull really hard. Ive also heard the polini pipe in action on g9's bike in person. Its sounds animal! I had really stiff clutch springs maxed and realized i was just wasting alot of low rpms cuz the beginning of my band was right around 7-8k. I switched to the polini yellows and it got up quicker and pulls the wheel up every time. You might also wanna try dropping down to the yellow contra. That red might be holding you down in a lower gear when u could be going faster sooner.

Hey sorry I never get on hardly, I did like you said and it worked! still using the red spring as I like to change one thing at a time, I have the yellow and I am about to toss it in now and see what it does. Acceleration is really good but I can just "feel" its a long ways away from doing a wheelie lol

[mantrans]

pg is dead after 9200rpm. There is no reason you shouldn't be spinning 11,500-12k. There will be guys saying they do 80mph on a stock corsa with pg. Sure, maybe if you were to go down a cliff, or down a mountain pass tucked with gravity and a tailwind. Look how hard it falls apart. This is on a corsa. This weekend I ran with a ported corsa mini with arrow and hes spinning 11,700. its a beast.

7.47whp PG+corsa




corsa+c16 pipe making 8.7whp at 11,500.


Pg is a terrible pipe for corsa said and done. Nobody will convince me otherwise Proof is in the numbers. That pipe is literally leaving 1.23HP on the table, and 2,000 rpm, which is going to equate to (x) mph. Wheelman can do the math on this one

Nice! I wanted some testing with the corsa pipe before I got back to you. I can attest for what you are saying because just swapping the pg out with the corsa.. no jetting not nothing and I blipped the throttle while fishing for my phone and the bike almost killed me. Pipe is killer. I am getting very very close on the tunning. Im running out of things to change, I am about to start a new topic about it if you would like to chime in! thanks!