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HPMX V Weber
vwo60 - October 28th, 2012 at 09:38 PM

http://www.youtube.com/watch?v=WP3fOWaaQy4&feature=related 
Worth watching.

psimitar - October 29th, 2012 at 12:07 AM

Um, yet right at the start they say that they have profiled the throttle shaft and increased the bore diameter to increase gas flow thro the HMPX. Therefore not a straight out of the box comparison.

If you knife edge the throttle butterflies, flow the throttle spindles and smooth the venturi's then any carb will flow better than it's out the box cousin.

Also, unless actually cast in America then the EMPI brand still suffer from poor Chinese manufacturing porosity and strength.

vwo60 - October 29th, 2012 at 05:46 AM

It is a direct out of the box comparison, these feature's are standard on the HPMX as they state that these improvment's have been made as part of there manufacturing process.

steve burgess - October 29th, 2012 at 08:31 AM

Iam running a set of cheap chinese 40 idf. went through them before fitting and all was good.They are running great so no complaints from me. Saved many $$
I think the early ones were bad so would be careful buying second hand.

snitz - October 29th, 2012 at 10:41 AM

Wifes 1916cc '70 beetle runs 40mm HPMXs..Runs really well but a little too rich on the idle jets.Despite this its quite economical..well compared to my twin turbo Legnum..lol.
Once run in its on a mates dyno to re-jet and check mixtures.Ive sold 5 pairs of 36idfs (3 sets on this forum alone) and honestly the quality is right up there in terms of the carbies..I think the hex bar linkage set up is of a lower quality than others but still performs well.

psimitar - October 29th, 2012 at 12:11 PM

Quote:
Originally posted by vwo60
It is a direct out of the box comparison, these feature's are standard on the HPMX as they state that these improvment's have been made as part of there manufacturing process.


Hmm, well I'd be interested to see how the Weber's would stack up against the Empi's with the same improvements made. That IMO would be a fairer comparison.

Still if the Empi's don't have any quality issues then they look like a good buy :)

matberry - October 29th, 2012 at 02:14 PM

I've had troubles with manufacturing issues with the HPMX's so I won't be recommending them, but that aside, it is interesting to note, the AFR's are different on both engines in the comparisons. This is because for whatever reason the HPMX wants a slightly richer set-up than an IDF, and the dyno sheets back this, therefore for a power comparison, surely the jetting should first be set for what the engine/carb combo requires before maximum output is tested. Then it would be a performance comparison. Anyway, I use and recommend Weber as driveability and longevety does not show up on a dyno pull.

Craig Torrens - October 29th, 2012 at 02:27 PM

if its on youtube.....well then it must be true :lol::lol::lol:;)

Klaus - October 29th, 2012 at 04:38 PM

nice to see they mentioned the fact you have to empty float bowls of swarf and set the float levels on the hpmx's ..ha

vwo60 - October 29th, 2012 at 06:56 PM

I think you are missing the point psimatar, there are both out of the box, weber would have to make the changes in the manufacturing process to the IDF's that the HMPX have standard.

coletrickle - October 29th, 2012 at 08:04 PM

Are the hpmx throttle blades the same diameter as the webbers that they copied?

matberry - October 29th, 2012 at 08:13 PM

Quote:
Originally posted by coletrickle
Are the hpmx throttle blades the same diameter as the webbers that they copied?
Yes

coletrickle - October 29th, 2012 at 08:20 PM

Thanks matty,I'll reserve my decision on the hpmx's for say 20 years!

psimitar - October 29th, 2012 at 09:05 PM

Quote:
Originally posted by vwo60
I think you are missing the point psimatar, there are both out of the box, weber would have to make the changes in the manufacturing process to the IDF's that the HMPX have standard.


Not really, they may be modified by the manufacturer after the casting process but as it's been internally massaged then it automatically has an edge over the Webers if all other dimensions are identical.

So it's like comparing an OEM cylinder head and a JPM cylinder head. Both 'straight out the box' but ones been played with so not the same.

I used to be able to modify the Weber DGAV on Ford pinto's to flow close to a pair of DCOE's for fuelling restricted race engines.

I'm just saying that if the Weber had the same manufacturers modifications done to them then that would be a more interesting comparison.

Craig Torrens - October 29th, 2012 at 09:20 PM

the youtube test is done by an Empi supporting person/company.........do you really think its going to be unbiased ???

Notice they dyno run the HPMX first......maybe its because after a few runs they know HP will drop off due to heat sink.

I bet if they pulled 10 sets of HPMX carbs out of boxes and tested them they would ALL have a different result......the same if they did it with webers

The only real comparison would be to tune the carbs to match the motor and then see which one produces the best result.

colin - October 31st, 2012 at 07:14 PM

Quote:
Originally posted by matberry
I've had troubles with manufacturing issues with the HPMX's so I won't be recommending them, but that aside, it is interesting to note, the AFR's are different on both engines in the comparisons. This is because for whatever reason the HPMX wants a slightly richer set-up than an IDF, and the dyno sheets back this, therefore for a power comparison, surely the jetting should first be set for what the engine/carb combo requires before maximum output is tested. Then it would be a performance comparison. Anyway, I use and recommend Weber as driveability and longevety does not show up on a dyno pull.


Very wise words Matt,
Each carb brand must be jetted individually for a true comparision.

Cheers Col

tar76 - October 31st, 2012 at 07:30 PM

Had a set of HPMX on my old panel and could never get them to idle right. they use to always play up if you let it sit and idle for too long, had to keep pumping the throttle every 30 seconds. that was my main bug bare with them use to really shit me at the lights.

70AutoStik - November 5th, 2012 at 05:26 PM

Hehehe, we tend to expect mindless racial prejudice from Americans, but over on thesamba the consensus seems to be the HPMX are looking good. The Spanish Webers have been getting worse and worse - so bad people are considering Kadrons...

I picked up a pair of their ICT copies as I needed something to get an engine running and it was actually cheaper than picking up a good used or stock carb here! I was actually shocked at the quality - I remember Empi as shipping crap that you wouldn't even want to hang on your wall.

So, I'm afraid I tend to agree with the Americans, the new Empi carbs are well worth a look. Ask a few people who aren't selling them what they thought of recent Weber offerings... Sad but true.

tar76 - November 5th, 2012 at 05:49 PM

Mine were the first model type but have heard the next gen were made better?

They wouldn't stack up to Dells!!:smilegrin:

OZ Towdster - November 5th, 2012 at 06:01 PM

Tarin , Dells are / were a great carby , right up to the point of trying to buy parts for them now , part of the reason i dropped the drla for the kaddies

vwo60 - November 5th, 2012 at 06:45 PM

I run 48 drla's and have had no problems getting anything i needed, all has been available, from the uk or us, as for going back to kadron, what a disapointment that would be.