Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[MadCVORG]

Hi folks,

I've been wondering whether it would be worth putting a 58mm throttle body on my 2011 'RUSE.  I have 10.5 pistons, new cams, ported heads, and other upgrades, and am now rated at 116/118. The problem is that I still manage 44mpg or so, but if I can get a decent bump in HP and TQ without losing too much mpg, I'd consider it. Just wanted to know if anyone has done some comparison on power vs. mpg with the 58mm (or even a 55mm) TB.  Cams are a Black Widow grind, similar to the SE-259 with an improved lower-end response.

[prodrag1320]

58mm will help on the big end (if yours heads are flowing over the 50mm) wont do anything  (in fact might hurt) bottom #'s

[HILLSIDECYCLE.COM]

Hi folks,

I've been wondering whether it would be worth putting a 58mm throttle body on my 2011 'RUSE.  I have 10.5 pistons, new cams, ported heads, and other upgrades, and am now rated at 116/118. The problem is that I still manage 44mpg or so, but if I can get a decent bump in HP and TQ without losing too much mpg, I'd consider it. Just wanted to know if anyone has done some comparison on power vs. mpg with the 58mm (or even a 55mm) TB.  Cams are a Black Widow grind, similar to the SE-259 with an improved lower-end response.

With a S/E 58mm,(tbw I assume) that'll match to your OEM port diameter, unless it has been changed.
It MAY pick up mileage, as well as power.
Scott

[TorqueInc]

Hi folks,

I've been wondering whether it would be worth putting a 58mm throttle body on my 2011 'RUSE.  I have 10.5 pistons, new cams, ported heads, and other upgrades, and am now rated at 116/118. The problem is that I still manage 44mpg or so, but if I can get a decent bump in HP and TQ without losing too much mpg, I'd consider it. Just wanted to know if anyone has done some comparison on power vs. mpg with the 58mm (or even a 55mm) TB.  Cams are a Black Widow grind, similar to the SE-259 with an improved lower-end response.

  Finished a S&S 106 build with headwork(06 heads) and there was no change in the torque curve from a stock 2010 throttle body to a se58 it did pick up about 4hp peak and changed the power curve from about 3700 to 6000.....still gets the same 45-46 mpg.

  do not see much of a change in a 110.....depends on how you ride

[sadunbar]

Hi folks,

I've been wondering whether it would be worth putting a 58mm throttle body on my 2011 'RUSE.  I have 10.5 pistons, new cams, ported heads, and other upgrades, and am now rated at 116/118. The problem is that I still manage 44mpg or so, but if I can get a decent bump in HP and TQ without losing too much mpg, I'd consider it. Just wanted to know if anyone has done some comparison on power vs. mpg with the 58mm (or even a 55mm) TB.  Cams are a Black Widow grind, similar to the SE-259 with an improved lower-end response.

If your throttle body is the choke point of air moving thru your motor, then with proper tuning, a larger throttle body could improve torque and power.  It depends on the collective flow of the entire system - air cleaner, throttle body, intake manifold, heads, exhaust and cams...  To big of throttle body can help torque and power but low speed ride ability can suffer...  As always, it's the total package that matters, not a particular component of the package.

[HILLSIDECYCLE.COM]

If your throttle body is the choke point of air moving thru your motor, then with proper tuning, a larger throttle body could improve torque and power.  It depends on the collective flow of the entire system - air cleaner, throttle body, intake manifold, heads, exhaust and cams...  To big of throttle body can help torque and power but low speed ride ability can suffer...  As always, it's the total package that matters, not a particular component of the package.

Well said explanantion.
Scott

[GMR-PERFORMANCE]

Well from a pure tuning stand point yes you will see gains. However the hp will be the one that picks up the most. and that point will be approx 4200 RPM +.

Tq should be curve should also broaden up due to increased cylinder fill.

As for the the stock unit flow too much that will not really be an issue as we install 58 MM on stock CVO heads all the time and do not have any issue. 

Not going to get into a flow number debate , this is what I know to be factual .. stock 50 MM is good for approx 115 hp on avg , take the same build and play with cams bigger or smaller and you will see that the tq curve can be moved around but peak numbers will stay pretty much the same.. Install the larger t/b and it makes more..  The stock heads are able to flow more than the the stock unit ( 50) can handle.

If I can get the time to pull up a few builds where we ran as a stage 1 ( ex tune a/c) vs stage 2  ( ex cam tune a/c) vs stage 3 ( ex cam t/b a/c and tune) you will see where it goes from there..


Several on this site have had us do this..

I have to tune to day so if I can pull up a few 110 sheets I will and over lay them to show the change.  I know the opinions on what the heads flow , flow charts etc..  Real world power to the tire at the end of the day has shown that the  larger unit will increase the power hands down even with small cams.   Now if that gain is worth the extra money for the larger TB labor , and tune well that is something only you can decide.

Good luck

[MadCVORG]

Thanks for the info, guys. I'll go back and look at the system--I know the heads were ported, with larger intake valves, but I don't have details/specs. I have a Fullsac 'B' pipe--and I think there was a port mismatch there--so I'll check that out too. Motor was built while I was overseas, so I didn't see the build in progress.  Dealer changed owners, so I need to find out where my mechanic is now.  I went on another long ride today, almost 200 miles at 70-85, and still logged xx+ (edit: 49.x mpg  -rgo).  Will keep looking, though.

[GMR-PERFORMANCE]

mpg really does not have to do with T/B size my  RG with a 124  and 66 will run in the 42-45 range two up. That is in the tune , there are some cases on big t/b race style engine ( more hot rod than cruiser) that it could be an issue. But for street stuff no reason not to get good MPG when tuned with most set ups.

[FlaHeatWave]

I was consistently getting 40-41mpg, 117", 58mmSE, 5.3inj, PC-V / Autotune, all 2-up/loaded at 80++. 35-38mpg around town/playing.

Went to TechnoResearch / Dyno Tune and mileage has dropped considerably...
We'll do some tweaking with the Maximus...

[MadCVORG]

That's what I've been looking for.....does having the larger TB (and injectors) seriously degrade mpg?  Maybe not....I've already done air cleaner, heads, cams, pistons, and exhaust, but kept the stock TB.  I error on my last post--actually got about 49mpg on this tank, but still have more miles to log before I empty it.  Most cruising 70-85mph, without excessive stops, and getting much better mpg than I thought I could with this setup. So, if I can bump up to a larger TB without sacrificing mpg, and get a measurable performance increase, I might go for it.

Thanks guys!

[HILLSIDECYCLE.COM]

A 110" head as-cast port ID is 1.750"...........the manifold ID of a 58mm S/E t/body is 1.750"........the 50mm's are much smaller.
Why would one want a step at that critical point?

[hrdtail78]

That's what I've been looking for.....does having the larger TB (and injectors) seriously degrade mpg?  Maybe not....I've already done air cleaner, heads, cams, pistons, and exhaust, but kept the stock TB.  I error on my last post--actually got about 49mpg on this tank, but still have more miles to log before I empty it.  Most cruising 70-85mph, without excessive stops, and getting much better mpg than I thought I could with this setup. So, if I can bump up to a larger TB without sacrificing mpg, and get a measurable performance increase, I might go for it.

Thanks guys!

I have actually seen better mpg with bigger injectors.  Remember that bigger injectors vs smaller injectors are going to deliver the same amount (basically) of fuel to reach the same target.  The difference is how long the injector stays open. ( all depending on both are tuned correctly )  BUT IME and in theory.  The bigger injector can deliver the fuel in a shorter amount of time.  This can help it be more of an efficient fuel delivery system.  Less time spraying on a closed valve, less time to deal with fuel stand off, less time to have cross talk.  We could even get into the topics of wall wetting and what happens on a slammed shut throttle and DE being active and why?

I don't believe in too big of a TB for WOT power, and with throttle progressivity helps a lot with taming big TB's, but I have a 66 on my 124 and I can't wait to replace it with my new HPI 62 because of light cruise response and noise.  Too much intake reversion.   

[HD Street Performance]

The bigger injector can deliver the fuel in a shorter amount of time.

Makes sense. Same was said by Chris Schroeder. Can a 65lb injector, Bosch EV14 for example, still have proper low speed control on these bigger motor builds? They claim minimum of 1.0 ms minimum pulse width.

[HILLSIDECYCLE.COM]

If a larger injector is wanted/needed by a given powerplant, then it only stands to reason that it'll run smoother and manufacture more power when that would be introduced...........no google search needed to figure that one.