Webbers vs Holleys
- Thread starter simonjrwinter
- Start date
Ron Earp
Admin
If the carbs are set up properly to provide the proper mixture then none. You've got an engine of X displacement and it needs Y fuel per unit of time to be properly fueled, there is no magic or voodoo there. Now, there is sometimes some magic and/or voodoo in getting the carbs set up properly, but that is a different issue!
For the ordianry Joe in the street, and even on the track you'd have to go a long way to beat the performance of a Holley on a good manifold, given that all you would have to do is fiddle with jet sizes to maximise, but as Ron says, if you could conquer the tuning process of the Webers and tune each choke individually, you'd probably be ahead on both power and mileage. But it would be marginal. Intake, heads and cam have to be added to this conundrum as well.
In general terms the difference between Webers(or other individual runner induction) and a Holley (or other 4v carb) is improved throttle response with the Webers.Contrary to popular belief a Holley 4v setup will probably give a bigger peak power figure; remember each cylinder sees the whole of the (Holley) carb which is why it is so easy to overcarb an engine in this configuration.
Trading a bit of peak power for fast throttle response is beneficial on the track, on the road the added complexity and cost might seem unnecessary.
Colin Artus
Trading a bit of peak power for fast throttle response is beneficial on the track, on the road the added complexity and cost might seem unnecessary.
Colin Artus
Tim Kay
Lifetime Supporter
The benefit of Webers.........exhilarating as you approach the threshold of mastery (not to mention the engines performance).
In other words, graduating from a stumbling fool with a screwdriver and a 'unisyn' to a surgeon like professor of the eight-barrel monster you get a sense of accomplishment /ubbthreads/images/graemlins/cool.gif
It's only taken me one year /ubbthreads/images/graemlins/crazy.gif (lots of help from you guys here, thanks) but 'baby steps' have finally started to pay off and I am getting close to that diploma /ubbthreads/images/graemlins/shocked.gif Who's coming to my graduation? /ubbthreads/images/graemlins/grin.gif
In other words, graduating from a stumbling fool with a screwdriver and a 'unisyn' to a surgeon like professor of the eight-barrel monster you get a sense of accomplishment /ubbthreads/images/graemlins/cool.gif
It's only taken me one year /ubbthreads/images/graemlins/crazy.gif (lots of help from you guys here, thanks) but 'baby steps' have finally started to pay off and I am getting close to that diploma /ubbthreads/images/graemlins/shocked.gif Who's coming to my graduation? /ubbthreads/images/graemlins/grin.gif
Webers seem to be good on the street but start to lack ultimate horsepower on engines over 300 cubic inches. We hogged out a set of downdraft webers to 52 mm and found that they still didn't flow as well as a single Holley.You start to run into reversion problems. Small block Chevys get around the problem by opening up the intake runners just before the head which allows flow from both throats of the carb to enter one cylinder.
Chris Duncan
Supporter
Let's take it one step further, what gets better mileage and performance, carbs or 8 Tbody EFI?
Chris Duncan
Supporter
"Or one step further - How many gallons of gas or how much neck snapping performance do you have to gain to justify 8 grand missing from your joint accounts?"
Probably about $500 worth, and the other $7,500 is for bling. /ubbthreads/images/graemlins/grin.gif
Probably about $500 worth, and the other $7,500 is for bling. /ubbthreads/images/graemlins/grin.gif
Kalun,
As far as an $8000, 8 stack EFI system goes, being able to turn the key and go, without any issues, in any weather, ain't so bad. Dialing things in by the stroke of a computer key, and have them STAY that way, is pretty nice too. The difference in performance has to be experienced, to be believed! Those three things alone, knock the "bling factor" down to a somewhat more reasonable number of 25% or so. Any gain in fuel economy has to be worth at least another 5%. /ubbthreads/images/graemlins/wink.gif
In short, $1600 of useless "automotive bling" in today's day and age, doesn't amount to squat! Look at the average "tuner car", if you want to see a pile of USELESS bling! /ubbthreads/images/graemlins/shocked.gif /ubbthreads/images/graemlins/grin.gif
Bill
As far as an $8000, 8 stack EFI system goes, being able to turn the key and go, without any issues, in any weather, ain't so bad. Dialing things in by the stroke of a computer key, and have them STAY that way, is pretty nice too. The difference in performance has to be experienced, to be believed! Those three things alone, knock the "bling factor" down to a somewhat more reasonable number of 25% or so. Any gain in fuel economy has to be worth at least another 5%. /ubbthreads/images/graemlins/wink.gif
In short, $1600 of useless "automotive bling" in today's day and age, doesn't amount to squat! Look at the average "tuner car", if you want to see a pile of USELESS bling! /ubbthreads/images/graemlins/shocked.gif /ubbthreads/images/graemlins/grin.gif
Bill
Just to ask another question,
Does one need to build the car with an 8-stack in mind, or can you build it, get on the road first with a holley and later on go to EFI?
I understand the RF loom is prebuildt with the MoTec EFI in mind, but do I really need to consider that now or can I change it later without huge surgery (fuel systems, swirlpots and all that malarky)?
Does one need to build the car with an 8-stack in mind, or can you build it, get on the road first with a holley and later on go to EFI?
I understand the RF loom is prebuildt with the MoTec EFI in mind, but do I really need to consider that now or can I change it later without huge surgery (fuel systems, swirlpots and all that malarky)?
Carsten,
My car began life with a 750CFM Edelbrock on a Performer RPM manifold, then an 800CFM on a Victor JR manifold, then finally a TWM 8-stack EFI manifold and Motec M4.
If you go the carb route, think about including EFI fuel return ports to your tanks, in case you get the urge(cash) to switch over to EFI. Retrofitting returns after the fact isn't easy or fun! /ubbthreads/images/graemlins/mad.gif Trust me on that one!!!! If the return plumbing is already there, changing over would be relatively easy. Sorry, there's no getting around adding more parts(fuel pumps, regulator, swirl pot, etc.) when you add an EFI manifold.
Bill
My car began life with a 750CFM Edelbrock on a Performer RPM manifold, then an 800CFM on a Victor JR manifold, then finally a TWM 8-stack EFI manifold and Motec M4.
If you go the carb route, think about including EFI fuel return ports to your tanks, in case you get the urge(cash) to switch over to EFI. Retrofitting returns after the fact isn't easy or fun! /ubbthreads/images/graemlins/mad.gif Trust me on that one!!!! If the return plumbing is already there, changing over would be relatively easy. Sorry, there's no getting around adding more parts(fuel pumps, regulator, swirl pot, etc.) when you add an EFI manifold.
Bill
Chris Duncan
Supporter
Yes Bill EFI is best, I was just commiserating with 40Bud about the hit on the wallet.
I'm using the TWM with the Accel Gen7, the Motec is too spendy in the states. I want it just for the experience of programming the ECU, that and trying to keep the emmisions down.
Another thing people should look at is a simplified fuel delivery system for EFI systems. This info is from www.kinsler.com. You can eliminate the swirl pot and one fuel pump by running a chamber inside each fuel tank with one high pressure pump inside each tank. This eliminates the external swirl pot and the normal three pump setup.
Esentially it's like a swirl pot inside the end of each tank. Just a 1.5 gallon area with a divider to separate it from the rest of the tank and a one way flapper door that allows fuel in but not out. You can even put a little fence around the pick up.
This removes one swirl pot and 3 fuel pumps and subsequent lines from the already crowded engine bay, and puts it all in the tanks. Only pressure reg and return switch valve and final filter are external. It also brings your total number of fuel pumps from 3 to 2. Which may lower your cost depending on pump model. Seems to me the high pressure internal pumps are cheaper than the external ones also.
I'm using the TWM with the Accel Gen7, the Motec is too spendy in the states. I want it just for the experience of programming the ECU, that and trying to keep the emmisions down.
Another thing people should look at is a simplified fuel delivery system for EFI systems. This info is from www.kinsler.com. You can eliminate the swirl pot and one fuel pump by running a chamber inside each fuel tank with one high pressure pump inside each tank. This eliminates the external swirl pot and the normal three pump setup.
Esentially it's like a swirl pot inside the end of each tank. Just a 1.5 gallon area with a divider to separate it from the rest of the tank and a one way flapper door that allows fuel in but not out. You can even put a little fence around the pick up.
This removes one swirl pot and 3 fuel pumps and subsequent lines from the already crowded engine bay, and puts it all in the tanks. Only pressure reg and return switch valve and final filter are external. It also brings your total number of fuel pumps from 3 to 2. Which may lower your cost depending on pump model. Seems to me the high pressure internal pumps are cheaper than the external ones also.
Kalun,
I am running one LP pump(Carter), only ONE HP pump(Bosch), swirl pot, regulator, and 6 port changeover valve w/associated plumbing. So far, having only one HP pump has worked out just fine. At least I saved the cost of in tank pumps! /ubbthreads/images/graemlins/smile.gif
My wallet is still bleeding profusely from paying for my EFI system, but it was worth the difference in performance.
The guys who dyno tuned my engine/Motec(Second Street Speed), originally suggested a Gen 7, but changed their preference to a Motec. I deferred to their judgment. They sell/install Accel, Electromotive, and Accel, so I assume they would know which would be best for my application.
Out of curiosity, I asked where I could find more bolt on horsepower. Their response was a Kinsler manifold, with 68mm TBs!!! At 68mm, those throttle bodies looked like they could each swallow a baseball! /ubbthreads/images/graemlins/shocked.gif
Your $8000 EFI figure was right on the money, when all was said and done. Where do I join the Commiseration Club? /ubbthreads/images/graemlins/wink.gif
More importantly, how much are the dues? I'm broke! /ubbthreads/images/graemlins/tongue.gif
How far along are you with your engine/installation? I have some TWM installation tips, which may help you out.
Bill
I am running one LP pump(Carter), only ONE HP pump(Bosch), swirl pot, regulator, and 6 port changeover valve w/associated plumbing. So far, having only one HP pump has worked out just fine. At least I saved the cost of in tank pumps! /ubbthreads/images/graemlins/smile.gif
My wallet is still bleeding profusely from paying for my EFI system, but it was worth the difference in performance.
The guys who dyno tuned my engine/Motec(Second Street Speed), originally suggested a Gen 7, but changed their preference to a Motec. I deferred to their judgment. They sell/install Accel, Electromotive, and Accel, so I assume they would know which would be best for my application.
Out of curiosity, I asked where I could find more bolt on horsepower. Their response was a Kinsler manifold, with 68mm TBs!!! At 68mm, those throttle bodies looked like they could each swallow a baseball! /ubbthreads/images/graemlins/shocked.gif
Your $8000 EFI figure was right on the money, when all was said and done. Where do I join the Commiseration Club? /ubbthreads/images/graemlins/wink.gif
More importantly, how much are the dues? I'm broke! /ubbthreads/images/graemlins/tongue.gif
How far along are you with your engine/installation? I have some TWM installation tips, which may help you out.
Bill
As always, the problem with any fuel metering device, carburetor, EFI, etc. is the tuning.A really well prepared Holley, correct main and secondary jetting, correct power valve and all other goodies,can add 30 hp easily over a "correct sized" Holley carb. Like everything else, the devil is in the details. Holley 4150 is good Holley by Stallion Racing Components is the best going.(TN)..(NASCAR/ARCA/etc.) RRD
Chris Duncan
Supporter
Bill
how much were your pumps?
here's the breakdown of my setup
twm induction w/32# inj. $4,000
2 in tank HP pumps w/filters $200
pressure reg $225
one way T valve $150
10mic filter $20
return switch valve $150
Aeroquip hose and fittings $500
Accel Gen7 $1750
Gen7 wide band 02 $750
total $7745
"I have some TWM installation tips, which may help you out"
Yes, any info is good, just bolted the manifold, haven't final bolted the Tbodies on and don't have the Gen7 stuff yet.
What did you do for an IAC valve? I'm thinking of doing without, it's possible according to Kinsler, all it affects is cold start and I don't have AC or anything that needs Idle compensation. My dyno/Gen7 tuner guy wants an IAC but he may just be wanting to sell more stuff, it's sort of difficult to add to the TWM setup.
RRD,
yes the "demon tweak" makes all the difference.
how much were your pumps?
here's the breakdown of my setup
twm induction w/32# inj. $4,000
2 in tank HP pumps w/filters $200
pressure reg $225
one way T valve $150
10mic filter $20
return switch valve $150
Aeroquip hose and fittings $500
Accel Gen7 $1750
Gen7 wide band 02 $750
total $7745
"I have some TWM installation tips, which may help you out"
Yes, any info is good, just bolted the manifold, haven't final bolted the Tbodies on and don't have the Gen7 stuff yet.
What did you do for an IAC valve? I'm thinking of doing without, it's possible according to Kinsler, all it affects is cold start and I don't have AC or anything that needs Idle compensation. My dyno/Gen7 tuner guy wants an IAC but he may just be wanting to sell more stuff, it's sort of difficult to add to the TWM setup.
RRD,
yes the "demon tweak" makes all the difference.
Chris Duncan
Supporter
Bill, why did your dyno guys want the Motec over the Gen7?
Interesting thread.
If you can bring yourself to forgo the bling factor why not install a 4 barrel throttle body on a victor jnr mainfold with inectors fitted directly into the runners.
This gives the best of both worlds - EFI accuracy and efficiency and the top end grunt that the 4 barrel and manifold offers. Even better it doesn't cost much more than setting up a carb to start with.
I had this setup originally and worked really well but had to give in to the bling factor. It was too irresistable.
Just my .02c worth.
RV
If you can bring yourself to forgo the bling factor why not install a 4 barrel throttle body on a victor jnr mainfold with inectors fitted directly into the runners.
This gives the best of both worlds - EFI accuracy and efficiency and the top end grunt that the 4 barrel and manifold offers. Even better it doesn't cost much more than setting up a carb to start with.
I had this setup originally and worked really well but had to give in to the bling factor. It was too irresistable.
Just my .02c worth.
RV
Kalun,
It's been a while, but I seem to remember their reason
was the abilty of the Motec to batch OR sequential fire the
injectors.
I can call them if you would like to know for sure.
Rick,
You've gotta admit, looking in that back window makes you smile
now, doesn't it? /ubbthreads/images/graemlins/grin.gif
Bill
It's been a while, but I seem to remember their reason
was the abilty of the Motec to batch OR sequential fire the
injectors.
I can call them if you would like to know for sure.
Rick,
You've gotta admit, looking in that back window makes you smile
now, doesn't it? /ubbthreads/images/graemlins/grin.gif
Bill
