Shop is telling me to stay with the Super E?

[Twistedspoke100]

Hey guys,
I am getting ready to get some HP upgrades done to my 05 Mastiff. The shop I am looking at is telling me to stick with the Super E. According to him he can get 120 plus HP and keep the E. He said the G is to big and I would lose throttle response. Is there any validity to this? If I can save a few bucks by keeping the E that would be great.

 

[No H2O]

FWIW I upgraded my 2005 Super E to a Super G and it made a noticeable difference but I'll defer to the more seasoned folks here

 

[mleach72]

The E carb can just about deliver everything the 117 needs in its present stock form. The G will deliver a couple more top end hp, but he is right, there may be a loss of low-mid range torque and throttle response, but it shouldn't be much. If you do any engine modifications (head work, cams, etc.), the E is going to become more and more of a restriction. If you are going to keep the E, there are restrictors in the manifold that need removed. This will require a new manifold or boring the restrictors. The E was used because with the restrictors in place, the engine cfm demand never exceeded the maximum flow of the E carb.

 

[Sven]

What mleach said. It's made more for the HP mods where little things count. Think of Bernoulli to explain it. Use an hour glass. At the narrow part, add 3 jet holes. The pull signal of the vacuum across the jet holes fills the cylinder chamber with a ratio of gas and air.

E - Torque at the bottom.
G - Torque at the top.

Where the G is the sacrificial lamb at the bottom, and one who chases only top end, does this carb perform better at a narrower range of performance. Remember, it's linear in performance curves.

He said the G is to big and I would lose throttle response.

So if we dissect what 'lose throttle response' means, we have to wiggle bernoulli's effect. It goes something like; who fills the void faster in proportion? Say we swap the thimble size diameter of the hour glass to a faster opening like a shot glass. The loss of throttle response is you first have to fill the larger diameter's area with air and you just slowed down the pull signal at the jet holes. That says less gas, the front end dives heading up in a linear throttle opening. So the speed event adds more air, less gas to fire off and there is your poor throttle response.

That's how it makes sense to me.

 

[Twistedspoke100]

What mleach said. It's made more for the HP mods where little things count. Think of Bernoulli to explain it. Use an hour glass. At the narrow part, add 3 jet holes. The pull signal of the vacuum across the jet holes fills the cylinder chamber with a ratio of gas and air.

E - Torque at the bottom.
G - Torque at the top.

Where the G is the sacrificial lamb at the bottom, and one who chases only top end, does this carb perform better at a narrower range of performance. Remember, it's linear in performance curves.


So if we dissect what 'lose throttle response' means, we have to wiggle bernoulli's effect. It goes something like; who fills the void faster in proportion? Say we swap the thimble size diameter of the hour glass to a faster opening like a shot glass. The loss of throttle response is you first have to fill the larger diameter's area with air and you just slowed down the pull signal at the jet holes. That says less gas, the front end dives heading up in a linear throttle opening. So the speed event adds more air, less gas to fire off and there is your poor throttle response.

That's how it makes sense to me.

Ok if my riding “fun zone “ is stop light to stop light and county roads would a E be better or a G ? The plan is to have the heads done shave the cylinders and add a better cam

 

[mleach72]

Ok if my riding “fun zone “ is stop light to stop light and county roads would a E be better or a G ? The plan is to have the heads done shave the cylinders and add a better cam

With those things done, you are definitely going to benefit from the G. You are going to get a much better "pull" above 4k rpm.

As general information to help you understand engine cfm demand and carb flows, I'll do a little carb 101.

The formula to figure out what size carb your engine needs is this:
(Engine cid x max rpm x volumetric efficiency)÷3,456=max engine cfm demand.

Volumetric efficiency is a bit of a guess, but with a little info, you can make a pretty accurate estimation.

A stage 1 harley with stock internal components runs about 80%VE. Our S&S engines, even in stock form, flow a good bit better, and should be about 85%VE. If you have a good cam installed, you are bit higher and getting close to 90%. If you have had your heads professionally done by someone like John Sachs (port, polish, big valves), you are in the 95-100% range.

As a general rule of thumb, use the smallest carb that covers the max cfm demand of the motor. Carb manifold flows can be found in this article I posted a while back.

According to John Sachs, our stock S&S heads with the 1.94" intake valves flow a max of 160 cfm. Keep this in mind when making calculations. Unless you have had head work done, any results will top out at 160 cfm.

Note 1: Mr. Sachs has stated that he knows the author personally and believes his results are fairly accurate.

Note 2: The author doesn't test the super E on the manifold, and he doesn't test the 42mm Mikuni at all. It's been a while, but I remember seeing manifold tests for both. The E was in the high 130's and the 42mm Mikuni was in the mid 140's @10" of water, IIRC.

For an example, I'll use my bike.
Basically stock BDM 117 with a 585 cam.
(117x5500x.9)÷3,456=167.58 cfm.
Again, the heads limit flow to 160 cfm, which is covered by my 45mm Mikuni.

I used 5500 rpm as max rpm. The rev limiter on my TH ignition is set at 5,984 rpm, but I don't make a habit of hitting the rev limiter. Max hp is probably going to occur below this rpm anyway.
I used 90%VE because I have the 585 cam installed. Actual VE is probably a bit lower, but I'm looking for an optimistic number here. If a carb can cover that number, then it will have no problem covering the "real" number.

Sorry if this too much information, but I'm bored.

 

[Reddickracing]

With those things done, you are definitely going to benefit from the G. You are going to get a much better "pull" above 4k rpm.

As general information to help you understand engine cfm demand and carb flows, I'll do a little carb 101.

The formula to figure out what size carb your engine needs is this:
(Engine cid x max rpm x volumetric efficiency)÷3,456=max engine cfm demand.

Volumetric efficiency is a bit of a guess, but with a little info, you can make a pretty accurate estimation.

A stage 1 harley with stock internal components runs about 80%VE. Our S&S engines, even in stock form, flow a good bit better, and should be about 85%VE. If you have a good cam installed, you are bit higher and getting close to 90%. If you have had your heads professionally done by someone like John Sachs (port, polish, big valves), you are in the 95-100% range.

As a general rule of thumb, use the smallest carb that covers the max cfm demand of the motor. Carb manifold flows can be found in this article I posted a while back.

According to John Sachs, our stock S&S heads with the 1.94" intake valves flow a max of 160 cfm. Keep this in mind when making calculations. Unless you have had head work done, any results will top out at 160 cfm.

Note 1: Mr. Sachs has stated that he knows the author personally and believes his results are fairly accurate.

Note 2: The author doesn't test the super E on the manifold, and he doesn't test the 42mm Mikuni at all. It's been a while, but I remember seeing manifold tests for both. The E was in the high 140's and the 42mm Mikuni was in the mid 150's @10" of water, IIRC.

For an example, I'll use my bike.
Basically stock BDM 117 with a 585 cam.
(117x5500x.9)÷3,456=167.58 cfm.
Again, the heads limit cfm to 160 cfm demand, which is covered by my 45mm Mikuni.

I used 5500 rpm as max rpm. The rev limiter on my TH ignition is set at 5,984 rpm, but I don't make a habit of hitting the rev limiter. Max hp is probably going to occur below this rpm anyway.
I used 90%VE because I have the 585 cam installed. Actual VE is probably a bit lower, but I'm looking for a optimistic number here. If a carb can cover that number, then it will have no problem covering the "real" number.

Sorry if this too much information, but I'm bored.

Nice info!!!

 

[Butch Cassidy]

.....something else to consider and add to the G carb for ‘better’ mid-range response is a plenum. A spacer in between the carb and the manifold. This increase in area after the jets and before the valves allows for a more ‘ready’ premix to be drawn in to the combustion chamber at a lower rpm. As your engine ‘breathes’ this new volume location allows more room for the new and used air to find their way more ‘cleanly’ to where and when intended.
it is an old drag racing trick...lost in this fuel injected era.

 

[john sachs]

Imo, the "E" carb is way to small for a 117" engine. Even in its stock form, I bore "E" carbs to 42 mm. for 80" EVO engines, and they respond great, with NO loss of low end torque. Realize 1 thing. These engines when developed, had to pass EPA emissions specs. S&S is trying to tell you something when they put the metal restrictor/adaptor plates on your 1.800" intake port heads. That bogus setup is like pissing in a lake instead of a moving river.
John

 

[pauldeepsea]

Per the s&s manual the E carb is recommended for 100 cu in and below,
I am probably going to change out my super e xxx modified carb on the big bear during rebuild s&s 100
But it never responded well with the 100”

 

[Butch Cassidy]

Per the s&s manual the E carb is recommended for 100 cu in and below,
I am probably going to change out my super e xxx modified carb on the big bear during rebuild s&s 100
But it never responded well with the 100”

Paul; Bob Maltz of xxx carb has passed. That modded E might be worth holding onto.

 

[john sachs]

Per the s&s manual the E carb is recommended for 100 cu in and below,
I am probably going to change out my super e xxx modified carb on the big bear during rebuild s&s 100
But it never responded well with the 100”

Remove the ( bomb site in the picture ), and replace it with a stock emulsion tube, and proper main jet. You'll pick up a minimum of 3 H.P. maybe more.
John

 

[Butch Cassidy]

Remove the ( bomb site), and replace it with a stock emulsion tube, and proper main jet. You'll pick up a minimum of 3 H.P. maybe more.
John

Yes. XxX Bob Maltz.!

 

[Twistedspoke100]

I went with a Super G and had John Sachs, The Legend, bore it out and also had him install a thunder jet.

 

[pauldeepsea]

Remove the ( bomb site in the picture ), and replace it with a stock emulsion tube, and proper main jet. You'll pick up a minimum of 3 H.P. maybe more.
John

Never thought of that , I really thought that the xxx carb was setup to deliver ?
I have never been able to dial it in, but will try that before changing it out ..
thanks John .
Plan on starting the build late 21 , frame is already powder coated .. and will start a separate thread . It won’t be as custom as the ridgeback but it will be fun

 

[DynoDave]

I have a Super G 'Mini Taz' that Bob Maltz built, on my S&S107. Has a .600 cam and runs like a beast!

 

[liferider]

You want to wake the bike up, put a Mikuni 48 on it!! Best up grade I made!