HarleyTechTalk

Technical Forums => Evo Sportster => Topic started by: alstar2 on September 20, 2018, 10:52:48 AM

Title: more hop
Post by: alstar2 on September 20, 2018, 10:52:48 AM
a friend has a 2004 883 with 1200 cyl (hd's) , no head work , straight pipes( i hate them too) stock carb/ac.wants to know
how much more hop(his words) he would get with a carb change.   thanks Al     :nix:
Title: Re: more hop
Post by: PC_Hater on September 20, 2018, 12:21:43 PM
None.

If he wants more 'hop' he has to do it properly...
Title: Re: more hop
Post by: rigidthumper on September 20, 2018, 12:31:25 PM
I agree- carb upgrade will not yield results, a simple upgrade is to bolt on a set of 2004 and newer 1200 heads. BTW, stock 1200 stage 1 (air cleaner/rejet/slip on mufflers typically get mid 70s torque and horsepower. stock 883 heads on 1200 cylinders usually make mid 50s power.
Title: Re: more hop
Post by: Hossamania on September 20, 2018, 03:36:01 PM
Cams will help up that even more.
Title: Re: more hop
Post by: Panzer on September 20, 2018, 05:52:50 PM
Try stock Buell heads.
Title: Re: more hop
Post by: alstar2 on September 21, 2018, 07:35:54 AM
thanks for the info but nothing about just a carb. i do hear you though.will check his bank.    Al
Title: Re: more hop
Post by: Hossamania on September 21, 2018, 09:06:58 AM
Quote from: alstar2 on September 21, 2018, 07:35:54 AM
thanks for the info but nothing about just a carb. i do hear you though.will check his bank.    Al

Quote from: PC_Hater on September 20, 2018, 12:21:43 PM
None.

If he wants more 'hop' he has to do it properly...

There was the answer to the original question regarding just a carb change adding more "hop."
Title: Re: more hop
Post by: bobrk1 on January 09, 2019, 11:50:34 AM
Send  stock  to  head - quarters  or R&R CYCLE  get  them  done  . H Q  did  mine  big twin very  happy 
Title: Re: more hop
Post by: aswracing on January 11, 2019, 07:49:56 AM
Quote from: alstar2 on September 20, 2018, 10:52:48 AM
a friend has a 2004 883 with 1200 cyl (hd's) , no head work , straight pipes( i hate them too) stock carb/ac.wants to know
how much more hop(his words) he would get with a carb change.   thanks Al     :nix:

Always work on what's holding the motor back. Working on anything else is a waste of time and money.

In lotsa dyno testing of carb swaps, we've found the stock CV40 to start costing significant power in the 90-95hp range. Below that, swapping the carb does next to nothing for you.

So when everything else about the build is capable of those kinds of numbers, the carb starts being the constraint, and that's when it makes sense to change it.

If you've got stock 883 heads, and a stock air cleaner, and stock cams, there ain't no way in Hades you're anywhere near that level.

Work on what's holding the motor back.
Title: Re: more hop
Post by: Pete_Vit on January 11, 2019, 07:59:22 AM
on my 1200 the most 'hop' I got was getting away from straight pipes (drag) to a good set of pipes. other great ideas from the members here  :pop:
Title: Re: more hop
Post by: Hossamania on January 11, 2019, 10:07:41 AM
Quote from: Pete_Vit on January 11, 2019, 07:59:22 AM
on my 1200 the most 'hop' I got was getting away from straight pipes (drag) to a good set of pipes.

Blasphemy! Drag pipes rule!
Title: Re: more hop
Post by: Pete_Vit on January 11, 2019, 11:06:15 AM
Quote from: Hossamania on January 11, 2019, 10:07:41 AM
Quote from: Pete_Vit on January 11, 2019, 07:59:22 AM
on my 1200 the most 'hop' I got was getting away from straight pipes (drag) to a good set of pipes.

Blasphemy! Drag pipes rule!
:hyst: I had 2 different set, I have to admit I liked 'em till I got my V&H's - 
Title: Re: more hop
Post by: Hossamania on January 12, 2019, 11:49:55 AM
I actually put drag pipes ($99 from Jireh cycle) on my 88" RoadKing twin cam. They sounded awesome, worked ok because I do not lug my motors, quite the opposite, but of course, they were going to get me sent to jail. I still have them, and I really want to put them back on my hopped up 95" motor, just to see what happens. No drinking while riding with those because I'm pretty sure I'm going to get pulled over by popo immediately.
Title: Re: more hop
Post by: Hossamania on January 12, 2019, 11:51:33 AM
OP, did your friend ever make a decision on the next step to add hop?
Title: Re: more hop
Post by: Adam76 on January 28, 2019, 03:10:14 PM
Quote from: Hossamania on September 20, 2018, 03:36:01 PM
Cams will help up that even more.
Hossamania, do you mean just cams added to what he already has?  What cams would you suggest and how much of a difference are you expecting without increasing displacement or compression?
Thanks
Title: Re: more hop
Post by: Hossamania on January 29, 2019, 08:51:47 AM
Quote from: Adam76 on January 28, 2019, 03:10:14 PM
Quote from: Hossamania on September 20, 2018, 03:36:01 PM
Cams will help up that even more.
Hossamania, do you mean just cams added to what he already has?  What cams would you suggest and how much of a difference are you expecting without increasing displacement or compression?
Thanks

I was adding to Rigid's response about upgrading the heads. Stock cams are designed to meet epa emissions and noise requirements, and be easier on the stock valve train. Upgrading the heads allows the heads to reach more of their potential. I can't give you actual horsepower numbers and how much increase their will be, I can only tell you that cams will increase the power, but also improve the power band, more power earlier and longer, more "snap", if you will.
Two identical motors side by side, except for a difference in cams (properly chosen), the bike with cams will make more power.
Title: Re: more hop
Post by: doubletrouble on January 29, 2019, 09:52:59 AM
Quote from: aswracing on January 11, 2019, 07:49:56 AM
Quote from: alstar2 on September 20, 2018, 10:52:48 AM
a friend has a 2004 883 with 1200 cyl (hd's) , no head work , straight pipes( i hate them too) stock carb/ac.wants to know
how much more hop(his words) he would get with a carb change.   thanks Al     :nix:

Always work on what's holding the motor back. Working on anything else is a waste of time and money.

In lotsa dyno testing of carb swaps, we've found the stock CV40 to start costing significant power in the 90-95hp range. Below that, swapping the carb does next to nothing for you.

So when everything else about the build is capable of those kinds of numbers, the carb starts being the constraint, and that's when it makes sense to change it.

If you've got stock 883 heads, and a stock air cleaner, and stock cams, there ain't no way in Hades you're anywhere near that level.

Work on what's holding the motor back.
well said.
Title: Re: more hop
Post by: Hossamania on January 29, 2019, 11:47:58 AM
Quote from: Hossamania on January 29, 2019, 08:51:47 AM
Quote from: Adam76 on January 28, 2019, 03:10:14 PM
Quote from: Hossamania on September 20, 2018, 03:36:01 PM
Cams will help up that even more.
Hossamania, do you mean just cams added to what he already has?  What cams would you suggest and how much of a difference are you expecting without increasing displacement or compression?
Thanks

I was adding to Rigid's response about upgrading the heads. Stock cams are designed to meet epa emissions and noise requirements, and be easier on the stock valve train. Upgrading the heads allows the heads to reach more of their potential. I can't give you actual horsepower numbers and how much increase their will be, I can only tell you that cams will increase the power, but also improve the power band, more power earlier and longer, more "snap", if you will.
Two identical motors side by side, except for a difference in cams (properly chosen), the bike with cams will make more power.

And to your question, I have not worked on any sportsters, but yes, just adding cams to what he currently has will add more "hop" than changing carbs would.
Title: Re: more hop
Post by: Adam76 on January 29, 2019, 07:42:17 PM
Quote from: Hossamania on January 29, 2019, 08:51:47 AM
Quote from: Adam76 on January 28, 2019, 03:10:14 PM
Quote from: Hossamania on September 20, 2018, 03:36:01 PM
Cams will help up that even more.
I was adding to Rigid's response about upgrading the heads. Stock cams are designed to meet epa emissions and noise requirements, and be easier on the stock valve train. Upgrading the heads allows the heads to reach more of their potential. I can't give you actual horsepower numbers and how much increase their will be, I can only tell you that cams will increase the power, but also improve the power band, more power earlier and longer, more "snap", if you will.
Two identical motors side by side, except for a difference in cams (properly chosen), the bike with cams will make more power.

Hossamania, this doesn't reflect the testing and dyno sheets uve researched for stage  1200s vs adding cams only.  Most if not ALL of the cams lost TQ below around 4000rpm and the only real gains in HP were above 5000rpm?

What bolt in cams only are you referring to that add power "earlier and longer"?

I'm gong through the the same process (see my other thread) so I'm vey interested.
Thanks
Title: Re: more hop
Post by: Hossamania on January 29, 2019, 08:34:23 PM
Well Adam, I have not worked on any sportsters, or done any real research on them, so you know more than I do at this point. I have to admit that I was just assuming cams would increase power as they do in every other Harley motor, and was responding originally to the OP's question about more "hop".
Are you saying that there is no advantage to changing cams in an 883 to 1200 conversion with stock heads, or that has had headwork done? Seems counterintuitive to what I have learned on this site and with my own big twin motors.
Title: Re: more hop
Post by: Adam76 on January 30, 2019, 12:47:36 AM
Quote from: Hossamania on January 29, 2019, 08:34:23 PM
Well Adam, I have not worked on any sportsters, or done any real research on them, so you know more than I do at this point. I have to admit that I was just assuming cams would increase power as they do in every other Harley motor, and was responding originally to the OP's question about more "hop".
Are you saying that there is no advantage to changing cams in an 883 to 1200 conversion with stock heads, or that has had headwork done? Seems counterintuitive to what I have learned on this site and with my own big twin motors.
Apologies, yes you are right.  If it is a true 883 - 1200 conversion,  then I would expect cams would definitely  make more of a difference than say just a cam swap in a stage 1   1200...  but to get a real idea of the exact gains cams wold make the OP would have to talk to one of the vendors like Hammer Performance or NHRS who do sportster upgrades for a living.  👍
Title: Re: more hop
Post by: Hossamania on January 30, 2019, 05:09:51 AM
That is where I would start. Go with the guys that really know.