A back to back dyno test between triple Weber Carburettors and Jenvey Heritage Series EFI Throttle Bodies, on one of Australia’s most favourite muscle cars, the LJ Torana.
Charge cooling from carbs. You're getting the effect of phase change in the Venturi since at WOT Venturi vacuum is inversely proportional to manifold pressure. In this low depression the fuel tends to boil due to pressure drop around the boosters. There isn't really enough time for it to properly boil per se because manifold pressure = atmospheric pressure at WOT (minus air cleaner restriction but close enough) the constant phase change in the Venturi area is having an effect on power by increasing air density slightly. In injection systems the fuel is injected but the system doesn't require a Venturi, but it seems you've compensated by playing with ram tubes positively varying volumetric efficiency.
I don't see a problem with running different trumpets with the efi compared with the carbs. That's all part of it. Each system needs its own special parts and equipment. It would be a bit like saying we will run fuel injection but we won't use injectors because the carbs don't have them. That's silly, each system has its own parts it needs that will be different to the other system. If the combination of parts in the injection system gives you more power or it drives more to your liking, then that is the superior system for you and whatever combination of parts it consists of works for you.
Good test. Have you ever heard of Keith Frank? He makes a replacement emulation tube that works on a totally different operating principle. He calls them Venturi Pump Tubes, or VP tubes. He is not great at marketing but i really want someone like you, with a dyno and weber ecperience to check them out. He also makes a bunch of other trick parts like idle jets with adjustable air bleeds.
Really good test. I think to make it better you could get someone to 3d print some new velocity stacks with an identical bell mouth profile and length to the webers big with a flange for the jenvey bodies.
I do and I dont miss my LC, it was a 192 with tripples, when the SB barina GSI came out, it absolutely distoryed the LC lol Plus all the 12'a and 13b's went turbo, so I had no hope racing them anymore. Then i started playing with the 1986 60 series Landcruiser.12Ĥ-T diesel 250hprwhp and 650 NM of torque lol
Thank you for ALL your honest and easy to understand results with this test. I am just about to update from a 32/36 Weber (which has been running super rich) on my 1966 1500cc Isuzu Bellett to a 38/38 Retroject EFI Throttle body and Autronic ECU.....this is a great insight to the fact it is NOT going to make it into a horsepower monster. All I am trying to achieve is better acceleration and driveability, as currently it is a slug off the line. I am also aiming to turbocharge it next year to get just a little bit more get up and go. Thanks.
Very hi psi injection via fuel pumps and injection can make a increase in Hp. Very costly for a top notch system. A cold air box on that application would also pick up around 10 or so Hp
Good video and I like the car (I had an LC with a 202 at 11:1 on 36/72 with triple SU), it serves as a good reminder of what we used to know when aftermarket EFI was hitting the streets with Holley throttle bodies, that the main difference is you don't have to retune EFI every time you change elevation. A perfectly tuned multiple carb setup on dialled runners for the throttle response is basically the same performance as multiport EFI on the same ignition, except you have to pull over and retune if you drive up or down a mountain or lose power with altitude change. Seasonal weather too. Basically I had to retune the SUs and reset the valve lash every second weekend plus whenever I changed elevation, which was the difference between beating or losing to a Brockie. Different story but the same my now ride is an 80s Merc six with a big cam and that was on K-jet, tried a franken standalone but couldn't reconcile the Bosch system so that's getting EFI now. On the milder cam though you wouldn't have got any benefit, the K-jet is a remarkably adaptive closed loop for a narrow band, being a vacuum system, it'll self adjust and auto-retune for any mods you throw at it until you do significant valve overlap, then it goes haywire. For a mild power build K-jet is better than EFI with barely any sensors, no wonder Porsche and Ferrari used it.
EFI is great. The only thing that stopped me going EFI over my twin (a million hours to tune) webers is that I wanted to keep my car true(ish) to its 1970’s heritage. I already have modern EFI cars and I find the webers quite fun from an enthusiast aspect.
Hi mate, I'm running triple 45mm webers. I'm interested in what you have done with the computer ignition set up, and also the throttle linkage. Can I get some help or info please
Not true… catalytic converter is easier to control with efi, but carbs can be very clean, but not ever changing based on converter needs…. That’s the hiccup
@@michaelbyrnes7944 obviously your understanding of combustion is set in the 70's. The world has learnt much in the last 50 years about getting a more efficient burn. FYI - cleaner emissions means more of the fuel energy is turned into power. Maybe you can rethink your Neanderthal ways
It’s a Haltech Elete 750. It could be a 550? It was a while ago so I can’t quite remember. In any case, it’s one of the lower spec Eleite’s. 99 percent sure it’s a 750.
@@jdfilms1426 Thanks for your reply. Im building an engine for my EH with an Irving stage 2 cylinder head with triple Webbers. I was going to run a wideband o2 sensor until I saw what you did.
Is that the customer who is banned from many workshops / machine shops in Sydney because he just hangs around like a bad smell? I think i met him at Dominator Engines one day
Its interesting i have always had the thought EFI injectors were an odd design very clumsy when you consider the better part of 60 70 years of development went into carb design and we arrived at a Venturi to deliver fuel at the ideal position in the intake stream with little fuel Pressure (relative) Why move it and redesign the wheel then try to compensate with higher injection pressures Why not retool the carb body and use the efi injector to metre the fuel to the Venturi then you get the best of both worlds
nope, if that was the case, all performance cars would still run carbs. I wouldn't even be looking at cars for this test, motorcycle carbs and injection is leaps and bounds better than anything running on cars, and you won't find a carb that works better than injection on a race bike ever.... Motorcycle tech is miles ahead of anything car related, always has been...
@@MickH60 it's because new cars have efi. Pro stock stayed carbs until forced to go efi to keep up with emissions and what people have in their every day cars. I owned a Dyno so I am telling you that carbies made more peak hp every time on my engine Dyno. That was 10 years ago. That is NA car engines I'm talking about.
![ได้เวลา! พาน้องแฝดฉีดวัคซีนครบ 1 เดือน🫣 [cc] แดนแพทตี้ SS2 | EP.52 |](http://i.ytimg.com/vi/IzeLtaXBLNE/mqdefault.jpg)
Charge cooling from carbs. You're getting the effect of phase change in the Venturi since at WOT Venturi vacuum is inversely proportional to manifold pressure. In this low depression the fuel tends to boil due to pressure drop around the boosters. There isn't really enough time for it to properly boil per se because manifold pressure = atmospheric pressure at WOT (minus air cleaner restriction but close enough) the constant phase change in the Venturi area is having an effect on power by increasing air density slightly.
In injection systems the fuel is injected but the system doesn't require a Venturi, but it seems you've compensated by playing with ram tubes positively varying volumetric efficiency.
no air cleaners?
I don't see a problem with running different trumpets with the efi compared with the carbs. That's all part of it. Each system needs its own special parts and equipment.
It would be a bit like saying we will run fuel injection but we won't use injectors because the carbs don't have them.
That's silly, each system has its own parts it needs that will be different to the other system.
If the combination of parts in the injection system gives you more power or it drives more to your liking, then that is the superior system for you and whatever combination of parts it consists of works for you.
Good test. Have you ever heard of Keith Frank? He makes a replacement emulation tube that works on a totally different operating principle. He calls them Venturi Pump Tubes, or VP tubes. He is not great at marketing but i really want someone like you, with a dyno and weber ecperience to check them out. He also makes a bunch of other trick parts like idle jets with adjustable air bleeds.
Really good test. I think to make it better you could get someone to 3d print some new velocity stacks with an identical bell mouth profile and length to the webers big with a flange for the jenvey bodies.
I do and I dont miss my LC, it was a 192 with tripples, when the SB barina GSI came out, it absolutely distoryed the LC lol
Plus all the 12'a and 13b's went turbo, so I had no hope racing them anymore.
Then i started playing with the 1986 60 series Landcruiser.12Ĥ-T diesel 250hprwhp and 650 NM of torque lol
Thank you for ALL your honest and easy to understand results with this test. I am just about to update from a 32/36 Weber (which has been running super rich) on my 1966 1500cc Isuzu Bellett to a 38/38 Retroject EFI Throttle body and Autronic ECU.....this is a great insight to the fact it is NOT going to make it into a horsepower monster. All I am trying to achieve is better acceleration and driveability, as currently it is a slug off the line. I am also aiming to turbocharge it next year to get just a little bit more get up and go. Thanks.
Very hi psi injection via fuel pumps and injection can make a increase in Hp. Very costly for a top notch system. A cold air box on that application would also pick up around 10 or so Hp
Would have been interesting to see what happened with the throttle bodies spaced off the head
Much difference in fuel economy?
Good on you. Thanks
Good test , thanks for doing it , I have a turbo EFI car and a turbo blow through carb car , no problems with either of them.
Great video and very informative. Thanks for sharing your knowledge with us minions.
That’s not fair 🦣🦓🐆🦒
Where did you get the wig from I need one :)
Top vid by the way
Great video gents.
Very interesting video. But have to ask, the car is very similar to the Opel Ascona A here in Europe, is it the same?
Looks somewhat similar around the nose, but not in other angles. The car has it's origins with the English Vauxhall Viva.
Good video and I like the car (I had an LC with a 202 at 11:1 on 36/72 with triple SU), it serves as a good reminder of what we used to know when aftermarket EFI was hitting the streets with Holley throttle bodies, that the main difference is you don't have to retune EFI every time you change elevation. A perfectly tuned multiple carb setup on dialled runners for the throttle response is basically the same performance as multiport EFI on the same ignition, except you have to pull over and retune if you drive up or down a mountain or lose power with altitude change. Seasonal weather too. Basically I had to retune the SUs and reset the valve lash every second weekend plus whenever I changed elevation, which was the difference between beating or losing to a Brockie.
Different story but the same my now ride is an 80s Merc six with a big cam and that was on K-jet, tried a franken standalone but couldn't reconcile the Bosch system so that's getting EFI now. On the milder cam though you wouldn't have got any benefit, the K-jet is a remarkably adaptive closed loop for a narrow band, being a vacuum system, it'll self adjust and auto-retune for any mods you throw at it until you do significant valve overlap, then it goes haywire. For a mild power build K-jet is better than EFI with barely any sensors, no wonder Porsche and Ferrari used it.
EFI is great. The only thing that stopped me going EFI over my twin (a million hours to tune) webers is that I wanted to keep my car true(ish) to its 1970’s heritage. I already have modern EFI cars and I find the webers quite fun from an enthusiast aspect.
Hi mate,
I'm running triple 45mm webers. I'm interested in what you have done with the computer ignition set up, and also the throttle linkage. Can I get some help or info please
Presents a lot of good points. I think you missed mentioning one of the key benefits, much cleaner emissions.
You know what you can do with your emissions bullshit
@@michaelbyrnes7944 I'm guessing U want me to do what you do daily?? Nah. I'm good.
I agree with this comment.@@michaelbyrnes7944
Not true… catalytic converter is easier to control with efi, but carbs can be very clean, but not ever changing based on converter needs…. That’s the hiccup
@@michaelbyrnes7944 obviously your understanding of combustion is set in the 70's. The world has learnt much in the last 50 years about getting a more efficient burn.
FYI - cleaner emissions means more of the fuel energy is turned into power. Maybe you can rethink your Neanderthal ways
Have you tried an Aussie Rotec ITB?
nice fair comparison
What model Haltec is that running ?
It’s a Haltech Elete 750. It could be a 550? It was a while ago so I can’t quite remember. In any case, it’s one of the lower spec Eleite’s. 99 percent sure it’s a 750.
@@jdfilms1426
Thanks for your reply.
Im building an engine for my EH with an Irving stage 2 cylinder head with triple Webbers.
I was going to run a wideband o2 sensor until I saw what you did.
Is that the customer who is banned from many workshops / machine shops in Sydney because he just hangs around like a bad smell? I think i met him at Dominator Engines one day
Its interesting i have always had the thought EFI injectors were an odd design very clumsy
when you consider the better part of 60 70 years of development went into carb design and we arrived at a Venturi to deliver fuel at the ideal position in the intake stream with little fuel Pressure (relative)
Why move it and redesign the wheel then try to compensate with higher injection pressures
Why not retool the carb body and use the efi injector to metre the fuel to the Venturi then you get the best of both worlds
I always found carbies made more peak power then efi. I always put it down to better atomisation with a carburettor
nope, if that was the case, all performance cars would still run carbs. I wouldn't even be looking at cars for this test, motorcycle carbs and injection is leaps and bounds better than anything running on cars, and you won't find a carb that works better than injection on a race bike ever.... Motorcycle tech is miles ahead of anything car related, always has been...
@@MickH60 it's because new cars have efi. Pro stock stayed carbs until forced to go efi to keep up with emissions and what people have in their every day cars. I owned a Dyno so I am telling you that carbies made more peak hp every time on my engine Dyno. That was 10 years ago. That is NA car engines I'm talking about.