TheSamba.com :: View topic

Sun Oct 26, 2008 12:39 pm

I'm not sure if this topic has been covered before. If so, would someone kindly link me to it, otherwise here goes.

What are the differences between IDF, IDA, and HPMX carbs? Which are better suited for street, and easier to tune?

Thanks.

Sun Oct 26, 2008 1:58 pm

IDF's are a lot more street tunable. The IDA's were designed for all out racing at wide open throttle. The HPMX is a Chinese copy of the IDF

Sun Oct 26, 2008 2:00 pm

The ones you listed all have the same Individual Throttle Body (ITB) style layout, but there are distinct differences between each.

The Weber IDA carb has become ingrained into VW racing history and lore as THE carb to use when power output is the prime concern, as such it's popularity is unmatched in those circles. They can be used on the street if drivability is not a big concern, but that's not to say that they connot have tame characteristics. It's possible to drill more progression holes into the progression circuit (read modified), which increases the carbs ability to meter fuel at lower engine speeds. They tend to be pricey when compared to other forms of carburation, so they tend to be used on higher-end builds and almost always show up in the VW magazines.

The Weber IDF is what I call a street version of IDA. It works better on the street, because that's it's primary purpose. I has all the things the IDA lacks to make it a street performer right out of the box, and the cost is generally less than an IDA of similar size. They also have large power potential, but again due to lore and magazines, they tend to get passed in favor of the IDA.

HPMX- do we really need to go here? Basically a knockoff IDF.
Anything from EMPI can be written off as junk, until proven otherwise. Some have reported good results, while the majority opinion is still EMPI=CRAP. My advice is not to touch them with a ten foot pole.

Sun Oct 26, 2008 5:43 pm

Thanks for the reply, much apreciated! As a result, I'm going to stick with the IDF carbs!

Now, there is just one final question! I've got a 1776cc with an engle 130 cam. What would you guys recommend for carburation on this particular motor? Single, or Dual? 40mm or 44mm?

Thanks!

Sun Oct 26, 2008 5:46 pm

W130 is a lot of cam for a 1776. What heads and valve size?

Sun Oct 26, 2008 5:52 pm

Bug_Guy wrote: What are the differences between IDF, IDA, and HPMX carbs? Which are better suited for street, and easier to tune?

Thanks.
Neither... Dellorto DLRAs are the easiest to tune and run on the streets.

Sun Oct 26, 2008 5:56 pm

vwracerdave wrote: W130 is a lot of cam for a 1776. What heads and valve size?

The engine (long block) came with a '62 project I purchased. I'm not sure what the valve sizes are, but the heads have the threading for the temperature sensor, so I'm assuming they are from a later model Beetle. Not sure if that helps or not! sorry.

Sun Oct 26, 2008 5:58 pm

Bug_Guy wrote: The engine (long block) came with a '62 project I purchased. I'm not sure what the valve sizes are, but the heads have the threading for the temperature sensor, so I'm assuming they are from a later model Beetle. Not sure if that helps or not! sorry.
If they are stock FI heads the valves are smaller that "normal" stock.

Sun Oct 26, 2008 6:04 pm

What Glenn said. I suspect you don't really know what you're dealing with, and I personally NEVER go on what people tell me when it comes to engine internals. As such, you should at a minimum pull the oil pump, and see if you can get a look at the end of the cam to verify what it is. There's usually ID marks there. If it is an E-130 I'd say you're looking at a bastard, in which case (if I were in your shoes) I'd tear it down and make something a little more street friendly. The E-110 is a good all around street cam, that's what I'd change to.

Sun Oct 26, 2008 6:29 pm

miniman82 wrote: What Glenn said. I suspect you don't really know what you're dealing with, and I personally NEVER go on what people tell me when it comes to engine internals. As such, you should at a minimum pull the oil pump, and see if you can get a look at the end of the cam to verify what it is. There's usually ID marks there. If it is an E-130 I'd say you're looking at a bastard, in which case (if I were in your shoes) I'd tear it down and make something a little more street friendly. The E-110 is a good all around street cam, that's what I'd change to.

The cam is indeed an E-130. And the valves are larger on this set of heads, then another set of dual port heads that I have from another 1776cc I have kicking around.

Just out of curiosity, and perhaps lack of knowledge, why would an E-130 not be suited for this engine? Thanks.

Sun Oct 26, 2008 6:44 pm

Engle wrote: W-130: Drag Racing Off Road competition only!

Too much duration- 308*.

Sun Oct 26, 2008 6:53 pm

Bug_Guy wrote: miniman82 wrote: What Glenn said. I suspect you don't really know what you're dealing with, and I personally NEVER go on what people tell me when it comes to engine internals. As such, you should at a minimum pull the oil pump, and see if you can get a look at the end of the cam to verify what it is. There's usually ID marks there. If it is an E-130 I'd say you're looking at a bastard, in which case (if I were in your shoes) I'd tear it down and make something a little more street friendly. The E-110 is a good all around street cam, that's what I'd change to.

The cam is indeed an E-130. And the valves are larger on this set of heads, then another set of dual port heads that I have from another 1776cc I have kicking around.

Just out of curiosity, and perhaps lack of knowledge, why would an E-130 not be suited for this engine? Thanks.

Just ran out to the garage do confirm the head P/N. They are 040 101 375. According to one of my manuals, that would make it a 35.5mm IN x 32mm EX head, made in Brazil.

Sun Oct 26, 2008 6:56 pm

To make this work, you need to either get better heads and lots of compression, or a shorter cam.

Sun Oct 26, 2008 7:39 pm

Bug_Guy wrote: I'm not sure if this topic has been covered before. If so, would someone kindly link me to it, otherwise here goes.

What are the differences between IDF, IDA, and HPMX carbs? Which are better suited for street, and easier to tune?

Thanks.

IDF = best Carb for street, best described as all around.
IDA = BadASS street/strip carb best describe as Drag only
HPMX = S H I T worst carb on market, better to give your money to a homeless guy than get these POS

Sun Oct 26, 2008 7:57 pm

Euro 67 wrote: HPMX = S H I T worst carb on market, better to give your money to a homeless guy than get these POS

It would be more accurate to have a homeless guy spray gas right down your carb throats with a spray can, than to let an HPMX do it. :lol:

Sun Oct 26, 2008 10:07 pm

Euro 67 wrote: Bug_Guy wrote: I'm not sure if this topic has been covered before. If so, would someone kindly link me to it, otherwise here goes.

What are the differences between IDF, IDA, and HPMX carbs? Which are better suited for street, and easier to tune?

Thanks.

IDF = best Carb for street, best described as all around.
IDA = BadASS street/strip carb best describe as Drag only
HPMX = S H I T worst carb on market, better to give your money to a homeless guy than get these POS

I'm really enjoying the HPMX bashing comments! :) In all seriousness, from an inexperienced carb tuner, how difficult are dual carbs to tune? I can tweak a stock 34pic-3, but getting duals to be perfectly synchronized thats another story! Anyone care to offer some good advice/tips? Any tools out there like a synchrometer that would help? A good book perhaps?

Sun Oct 26, 2008 10:27 pm

A snail synchrometer works the best. But getting your carbs in synch will be impossible if your linkage isn't set up properly. Not to mention any jetting issues you may have.

Mon Oct 27, 2008 2:59 pm

Setting up dual carbs is not any harder then setting up a single carb. The only difference is that you have to do the same thing twice.

Mon Oct 27, 2008 4:50 pm

Glenn wrote: Bug_Guy wrote: What are the differences between IDF, IDA, and HPMX carbs? Which are better suited for street, and easier to tune?

Thanks.
Neither... Dellorto DLRAs are the easiest to tune and run on the streets.

X2.

Mon Oct 27, 2008 9:24 pm

http://www.aircooled.net/gnrlsite/resource/articles/carbs101.htm

great read on carbs. talks about IDAs and IDF towards the bottom

Quote: It's important to note that the DRLA carb sizing is 1 step larger than the equivalent Weber. A 36 mm Dellorto is equivalent toa 40 mm Weber; a 45mm Dellorto is equivalent to a 48mm Weber; etc.

^^^ I never knew that until reading this article