need more air, head porting?

[bigbusabigbusa]

want to thank you guys in advance for all your knowledge and help. got a few questions about my bike. gen 1 1507 I currently run web 395intake and 378exhaust cams, the head is stock. when at the dyno the power curve goes flat at 8500and the duty cycle on the injectors is at 95%. tuner said I have to port the head cuz it's running out of air. I know by increasing air flow I will have increase fuel so my questions are can I run the cams I have with a ported head or do I have to get bigger cams. this is a daily ridden bike so I'm not looking for every horsepower and don't want to run huge cams if I don't have to. second question, with the fuel I've been reading about s2000 injectors and I see they come in diff sizes or cc. which do you suggest and do I need a diff pump or will just injectors be enough. thanks again for your help

 

[megawatt]

Paging Goldenchild... These are questions he can definately answer for you and provide the parts you need.

I never heard there were different S2000 size injectors. Stock, Honda blackbird, and S2000 injectors (small, medium, large) are a direct fit that I can reemember for our busas. Tuners all have different methods for tuning but the last person I dealt with would prefer to stop at 90 duty cycle and leave the last 10% in reserve. Maybe due to tuning on a stage 1 turbo bike but 90% was the preferred ceiling to handle the what if's in life.

I would not think bigger cams on a street bike would be that comfortable on an already huge engine. Hope you get some helpful info on your scooter, good luck.

Bump to the top for you.

 

[SABUSABOY]

You can upgrade the injectors to Blackbird or S2000 injectors, but you might need to upgrade your fuel pump just as a precaution.
The cams you have are perfect for street use, going to big will bring its own set of problems with cam, bucket and seat wear due to higher spring pressures needed for bigger cams. If you decide to go bigger cams, you going to have to use someone who knows how to build them with bigger cams and do regular oil changes and cam and bucket inspections to make sure they dont go bad and keep a record of valve clearences at each inspection which will show if you have a problem or not. Porting should help the 1507 breathe a lot better, but with porting comes more air, so more fuel would be needed.


Also check you cam timing, it might be the reason your numbers are going flat at 8500. Just my .02

 

[jacob123]

this isnt very productive but i have to ask. why go with such a huge engine for your daily bike when you already had tons enough power for that catagory.. and if i was gonna put tons of doe$$$$$ into such a project id certainly want most of the ponies that i could get. just had to ask.. sorry good luck with your mods.

 

[GoldenChild]

Okay so I'll step into the water a little, but if I see your fin come up I'm out lol..

First off let's see if I can tell if your tuner has a clue, I'm already suspect... ???.

Mileage on motor since built?
What fuel pump is in the bike?
What is fuel pressure set at?
When was last time injectors were cleaned and serviced?
What size springs in the bike and what is seat pressure?
what is the compression?
Who built the motor?
Where are the cams set?
Do you know what the a/f was at 8500?
Do you have a dyno chart with he a/f showing?

want to thank you guys in advance for all your knowledge and help. got a few questions about my bike. gen 1 1507 I currently run web 395intake and 378exhaust cams, the head is stock. when at the dyno the power curve goes flat at 8500and the duty cycle on the injectors is at 95%. tuner said I have to port the head cuz it's running out of air. I know by increasing air flow I will have increase fuel so my questions are can I run the cams I have with a ported head or do I have to get bigger cams. this is a daily ridden bike so I'm not looking for every horsepower and don't want to run huge cams if I don't have to. second question, with the fuel I've been reading about s2000 injectors and I see they come in diff sizes or cc. which do you suggest and do I need a diff pump or will just injectors be enough. thanks again for your help

 

[bigbusabigbusa]

bike has 10000miles since the build.has stock fuel pump and stock pressure regulator injectors cleaned at build time, ape 65pound springs, don't know seat pressure compressionis 14to 1, cams are at 106intake 106exhaustexhaust, builder was a Suzuki service rep. only the best parts were put into this bike 125pound oil pressure valve, carillo rods, Brocks pistons marine crank, web cams, oil baffle in the oil pan, ape springs, crank lightened and balanced and a host of other things. I have had zero problems in the 10000miles I put on it last summer. has the bearings and cams and buckets all checked and all look perfect as of now. thank you golden child,I respect your wisdom very very much.Jacob 123I built this bike cuz I wanted a torque monster to play around on. I could've built a turbo or nitrous bike for half of what this build cost me but I like all motor. I'm not into racing so I don't have to have every house possible but I do want to get a safe reliable amount out of it. a motor this big has to breathe so I'm thinking I'm leaving allot of horses on the table with a stock head

 

[GoldenChild]

Well you don't add hp to a bike without having enough fuel volume to support it. What does it take to make power( a fire), The Fire Triangle consist of fuel/air/spark. If you have spark and air(naturally all around us), what's missing? It's out of fuel, you need a bigger internal pump or a complete aftermarket pump, reg and lines...I ask about tuner cause why would he add more air to something and not have fuel to burn it? This would put you in a even worse lean state correct? what does a area do when it creates lots of heat?



I'm asking who the tuner is not engine builder to tell you opening head will solve this issue, who is he again?

 

[methodicreign]

im my personal opinion, and limited engine tuning eperience. It would depend on your air fuel ration at 8500rpm and up. if your burning rich already an add more air you might get away with current fuel mapping. its all stoichiometric at this point

 

[GoldenChild]

Well you would think if the tuner saw it was rich, it wouldn't need more air, it would just need to be leaned out by removing fuel

Maxing the injectors out, would make you say man i can';t add anymore fuel to this lean motor so maybe i need more fuel volume... The stock injectors are good for say 325 hp, take that from your fuel system equation and what's missing? Fuel Volume,how do you get more volume, a bigger pump...How do you reduce the #'s in injector duty cycle you add more volume, how do you do that, you need a bigger pump... See where the road leads? same place it started a lack of fuel volume..

im my personal opinion, and limited engine tuning eperience. It would depend on your air fuel ration at 8500rpm and up. if your burning rich already an add more air you might get away with current fuel mapping. its all stoichiometric at this point

 

[bigbusabigbusa]

thank you golden child. the tuner is a place called fast bikes located in grand rapids in mi. he didn't say anything about more fuel. he just said it was out of air so I assumed I would need more fuel if I added more air.this is a gen 1bike and I thought the stock injectors were only good for about 230hp. so to make sure I'm understanding you correctly, the stock injectors are good for 300hp on a gen 1 so I just need a better pump to achieve more volume? also is this pump I need something you sell as I would love to do business with you

 

[bigbusabigbusa]

forgot to add that air to fuel ratio is 12.8 to1. thanks again for all your help and willingness to share your knowledge. I look forward to doing business with you . I would like to thank everyone else for their input also