TheSamba.com :: View topic - Comparing IDF PowerBand to DRLA PowerBand, Misconceptions?

Thu Dec 07, 2017 1:35 pm

Hello, here we go, comparing how an IDF Weber Carb Compares to a DRLA Dellorto Carb.

This is over the entire RPM Spectrum with the Same Engine.

So, does one out perform the other on the Street? Or Drag Strip, or on a Dyno?
Any info will be appreciated of first hand knowledge, that is for sure, hear say is just that with out some info to back it up.

Thing is I have had both, but, one engine was a 2110 Single Carbed 44 IDF, and now I have a 2180 with Dual 40 DRLA's. So, I really can't compare.

Point of why this discussion is I could not find any relative "Great" info on the topic, that or I just over looked it.

So, I have an 2180 I need to bump up the carbs on. And keeping Duals... So, what to go with?

New Webers? New EMPI D's(EMPI Version Dellortos DRLA's)?, Used DRLA's? Used IDF's? Think that about covers it...

So, RPM Spectrum, yes, how do the IDF's comapare to DRLA's on a Dyno Lets Say or Real World Driving? Street is my thing so going to more or less focus on that for why this topic has come up. Also, why, safety. Yea, I when I did my engine, I went with a mild set-up do to the roads I run plus getting use to the Super after a bunch of everything,lol..

Anyway, lets hear some good info and feedback for I have not seen the info.

Ok, so here it goes, on the same engine, done up stroker, dynamically balanced and all, do both carbs work the same- putting out the same power delivery and torque through out the entire RPM range?

I do know more, but let your minds wonder on this... I only have had the DRLA 40's Duals on the 2180, and engine is under carbed, Have 34 Vents in it now. So, as the previous paragraph mentioned which dual carbs to go with, and being DRLA 45's or 44 IDF's I would think? Don't need over fueling it as well with 48 IDA's or 48 IDF's which I think would happen for a street car in the mountains. Yea, No Kicking out as well on the chatter bumps or wash board... Over the mountain I would go,lol....

So now you have heard my quandary. But yea, RPM Range(HP/Torque/Delivery) and how they may differ on the IDF's vs. DRLA's, been happy with both, but application was part of that I may thank. RB

Thu Dec 07, 2017 1:55 pm

A hole is a hole so at full throttle it's a hole. Jetted correctly the power is determined by the size of the hole not by what brand of hole you have on there

Thu Dec 07, 2017 1:57 pm

Drivability? RB

Thu Dec 07, 2017 2:00 pm

Driveability comes from using the correct size hole but you did mention powerband

Thu Dec 07, 2017 2:04 pm

Yea, through out the RPM Range, so, lets say this, like how 2 Stroke MotorCross Engines DIffer, in the Power Band Delivery, at what RPMs they come on and all that if you know bikes...

But, like my DRLA's with there "Fluidness" feel at the throttle over the RPM's Range with this Cam(Engle 120 w/1to1 Ratios). So, in contrast to this statement, lets say do for example here only, do IDF's have Spikes through out the RPM Range? IF all the Holes are the Same? lol RB

Thu Dec 07, 2017 2:07 pm

Had to think do I add this to the above Post or Not, but "Progression Ports" come to mind, DRLA's have 5... Hummmm.... RB

Thu Dec 07, 2017 2:10 pm

I had a 2165 motor that drove better on 44IDFs than 48 Dells same power.
I think you are confusing power curve which is a full throttle test and the tunabilty of different carbs

Thu Dec 07, 2017 2:19 pm

What you said, but just slightly touching the throttle pedal and how the engine reacts, driving. Slow or fast or Slow to Fast, not drag racing all out pedal to the floor.. More Sensible zooming/cruising the back roads... How one carb may "Crack In" when doing it..... Something like that, just trying to describe a feel of how they may differ, hell, may have it backwards,lol....

With out a graph it is hard to explain... Figured this maybe an issue with manufacture reports on performance..... RB

Fri Dec 08, 2017 6:07 am

a carb is a carb :roll: diff tune to each one ect.
If u want a Power Band like a 2 stroke ,Just add a 'Turbo' :lol: :lol: :lol:

Fri Dec 08, 2017 6:11 am

If identical carbs (idf and dells) were tuned correctly, I don't think anyone could tell what brand they were driving from the drivers seat.

Fri Dec 08, 2017 8:39 am

esde wrote: If identical carbs (idf and dells) were tuned correctly, I don't think anyone could tell what brand they were driving from the drivers seat.
But you can hear it.
The problem with comparing is also that there are so many versions of the IDF.
If we compare say a set of 40 68/69 against a late model DRLA the power difference is minor to none. Tunability is also great on both carbs. The 40 IDF 70/71 is inferior and significantly more difficult tune get into a proper tune.

Take a 44 IDF versus a 45 DRLA and the 45 WILL outperform the 44IDF if the engine has the potential.

48 IDF versus 48 Dells, Performance wise they are very similar.

The real difference is ease of tune. In general the DRLA´s are easier to get a nice fuel curve with.
If the above 2165 did´nt need 48´s there is typically a good reason to why it runs better w. 44 IDF.

T

Fri Dec 08, 2017 9:01 am

esde, that is what I am looking for is feedback on the carbs and how they perform, if you can tell a difference if the carbs were in the same sizing.

I do like my DRLA"s, but lack top end. So I am in the mkt for carbs, thing is like to buy new DRLA's which we know they stopped making, but now we have the EMPI D's on the mkt and info is trickling in slowly on them...

But yea, drivability is what I am looking at and smoothness at the throttle pedal if the engine is the same engine for both carbs have been ran on. Like if they have "Holes" or "Gains" in certain RPM Spectrums/Areas. RB

Fri Dec 08, 2017 9:21 am

I don't mess with carbs anymore but for a 2180 you could try putting some 32 or 34mm venturis in there to give it the flow it needs but you may have those already

Fri Dec 08, 2017 9:25 am

I read something where David Vizard said that Dellorto side drafts had better fuel atomization than the Weber DCOE, and he could make more power with them. It also seemed like he didn't know exactly why that was. I don't know if DRLAs have the same fuel delivery system as the side draft, but it was interesting nonetheless.

Fri Dec 08, 2017 9:27 am

Paul.H, Yea, the 34 Vents are in. Thing is this, had a VW guy tell me since my DRLA's are 40's, theortically you can go up to a 40 mm Vent...

Ok, so in contrast to that, do they even sell or how would the carb suffer if I could fine 36 mm Vents? Do you get air turbalance through the carb or after into the Manifold(developing a flat spot in acceleration)? RB

Fri Dec 08, 2017 9:54 am

40's are too small really if you want top end out of your motor.44idfs would be the best choice with a std 36mm vent. Putting oversize vents in a small carb will effect it's ability to pull the fuel at low speeds and you will have jetting and tuning issues.

Fri Dec 08, 2017 10:21 am

Paul.H, so drivability they both are about the same? Or are the Same? RB

Fri Dec 08, 2017 10:26 am

Paul.H wrote: 40's are too small really if you want top end out of your motor.44idfs would be the best choice with a std 36mm vent. Putting oversize vents in a small carb will effect it's ability to pull the fuel at low speeds and you will have jetting and tuning issues.
Generally yes. But if the engine is big in relation to the carbs, a larger venturi, say a 36 in a 40 mm Dell can work well if you have a good venturi shape where the vacum draw is good. you can easily find 5-10 hp if you pay attention to what the engine tells you. There is of course a limit with everything and the easy way is of course to increase carb size.

T

Fri Dec 08, 2017 10:28 am

Alstrup. would you try 36 vents in a my situation first before purchasing any other carbs? RB

Fri Dec 08, 2017 2:58 pm

On a 2180? Definitely