FBIII

I had 3 45 dcoe's on a 4 liter aston Martin 6 along with Cosworth Pistons, gas flowed head and real big cams. It was a monster. The downside was it was almost impossible to start when the temperature fell below 45. It would pop and spit and ralph raw gas. Maybe Hammer would be better off with a set of 48 IDF's. I think they include chokes, if you are brave enough to use them, and I think they are also shorter than the IDa's.

GRTWHT

Old thread I know, sorry but I'm looking for a video of a running 928 engine with the 4 downdraft webber setup. Would anybody have seen this and point me to where it may be please?
I have seen it but cannot find it any more (Youtube maybe??)
It had an interesting idle. I would love to know what other specs the engine has if I ever find the video. (16v engine)

Cheers,
Glenn
'81 928
AU

danglerb

I never got much more information from the seller, but a few months back a 928 track car with webers was for sale on CL here in SoCal. Seller told me it sounded like a pack of motorcycles.

Snip of his reply to me.

"I had the car modified (20K) for PCA track use by Haus of Performance in Costa Mesa. The engine is fully polished & was on the cover of a POC magazine. Internally it has been completely re-built with hotter cams, head work, webers, headers, etc. I also had it re-painted the original black."

John Speake

There was a track car on Oz that ran Webers. Ask Nick McKenna....

OBehave

There is a Rennlister named Belgium Barry who has made a clone of Carls race car over there and he was running Webers, there is a huge thread of the build here somewhere with pics and all.

GRTWHT

Oh yeh of course, I think thats a 6.0L with 4 sidedraft webber setup. Not the one I was looking for but thanks for reminding me John.

Glenn
'81 928
AU

belgiumbarry

i did indeed tryed IDA48... but got them not well balanced , also nobody in Belgium who could help me ... ( with sets jets, venturis etc... ) tryed a few setups ( had to order the jets..) but didn't succeed. Problem was the "transition" spots...

Now we build back to a "race" injection system ( Emerald from the UK )

Attachment 385736

http://www.youtube.com/watch?v=YYFNKfilU-0

docmirror

Can I have your Webers?

dr bob

I'm not sure why, with today's afermarket EFI systems, anyone would wish for IDA's on either a road or race car. Tuning with a laptop is way easier than the 'let's try this and see what happens..." method common with Webers. Keep in mind that you need 8 sets of everything you might want to change too. As mentioned earlier, there are lots of things to 'tune' on IDA's. The idle-to-midrange transition tuning that Doc mentions, for instance, is a combination of very interactive idle mixture on the bleed screw, emulsion tube, idle and mid-range mixture via jets, accelerator pump cam and spray tube. Of course then there's the issue of getting the main ircuits tuned; they cause chnges in mixture from just off idle. And-- the IDA's have no compensation for changes in air density. Temperature, altitude, humidity changing? An opportunity to re-tune! Most street-tune engines can be made driveable in a few hours, with some conservative (read: rich) mixtures. For max power and transition smoothness in a race-tund engine with big valves and lumpy cams, new attention is required whenever anything is changed or changes. I have literally cases of little plastic parts trays with Weber tuning parts someplace in my collection. If you aren't equipped with a similar collection, you'll most likely come up with compromised tuning for whatever your application.

If you want the look of the big bell stacks, consider using individual throttles and modern EFI. It's cheaper, faster, more accurate, and MUCH easier and cheaper to tune.

GRTWHT

Thanks OBehave.. I got it, very cool.

Glenn
'81 928
AU

90 S-4

Not mine, but I thought the pics might help

GRTWHT

This is true, I remember having a similar 'tuning kit' just for 1 Carter AFB - and thats only 4 throttles !!

Pretty hard to beat the look of that webber setup, even if they were a pain they still look fast

Glenn
'81 928
AU

Iwanna928

Has anyone ever looked at imagineinjection.com? They modified the webers for fuel injection. It is pricey but looks like a really cool product.

Any thoughts on this if you take a look. Might be the way to top off the head cam intake package that I am looking at.

Looks like webers aren't all that hard to fit to our manifold.

Stephen

turbochad

I have had Webers and Dellortos on both VWs and Porsches. I have not had to tune them on engines larger than 6 cylinders but I have the following thoughts to offer to those who are considering trying this mod.
1. The transition problem in 2 barrel IDA's has been solved by VW tuners. You can send your carbs to JayCee enterprises and they can add the extra holes to the idle circuit to solve this common problem. This was a design issue as these carbs were never considered for street use by their makers. With this mod the transition is silky smooth.
2. Phonelic spacers should be used between the manifold and the head to stop the transfer of heat into the carbs which caused fuel boiling. This is the result of modern fuels which have a much lower boiling point than older leaded fuels. This vastly improves the issue of fuel boil.
3. I find that the biggest mistake that people make in setting up a weber system is not properly setting the float levels and fuel pressure. Most of the issues of popping in corners and difficult tuning are caused by this or worn out shafts (air leaks). If you have the floats correct and the pressure within specs the rest is what is commonly thought of as tuning (synchronization, choke sizing and jets). With a little planning using the weber tuning manual by Bob Tomlinson you should be able to get the hardware settings within a tenth before every starting the motor. If you follow the air synchronization procedures the carbs are not hard to get to work correctly.
4. Set up properly (read item 3 above) IDAs are not that sensitive to air density changes and humidity. I live in Colorado and regularly run both my weber fitted cars in altitude variations of 4,000 feet without needing to change jets (my 911 runs great at 9,000 feet).

I rely on my carbs to determine the tune of my motor not the other way round. Remember carbs don't go out of tune unless they are worn out or improperly set up. If my car starts running poorly, I go to my ignition system or my valve train to see where the problem is. Carbs provide constant metering of fuel based on air velocity and don't feature wear items (fuel filter is the only exception) like other systems do. The key is the initial setup.

I would love to see a properly set up 928 with a four pack of IDA's. Cut holes in the hood and have a lexan cover made like the old ferraris with the air horns sticking through the hood plane. The horsepower would be far in excess of the stock FI system and would be close to an ITB FI system. It is far more unique than FI and the thrill of a weber at full song is second to none.

turbochad

My next fantasy project is a '32 pickup chopped, channeled and sectioned with a 32v stroker 928 engine with four IDAs a shortened torque tube and 5 speed transaxle in the back. Polished block, wrinkle finished valve covers and iconel headers with direct fire ignition. Adapt the Weissach rear sub frame to the chassis and polish everything. The body would be all ratted out with rust and pin stripes. I am thinking show quality german drivetrain with rat style american body iron. It would not be the same with out the webers!