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I know there have been some topics about this, but none of them really answered the question wich intake set up gives the best performance on a 24V transaxle.
I use the 75 V6 intake but with the openings from the 164 24V manifold welded to the 6C plenum, the short intake tubes are cut 164 24V QV chrome tubes.
I think this set up is robbing power and moves the power band way too high up. Another problem is that the original rubbers don't last because there's too much tension on the rubber.
I'm not too happy with this set up although it looks great.
One sollution would be to use intake pipes that line up perfectly with the 24V openings in the 6C plenum (are they for sale??????) and the other sollution would be to go with the FWD set up.
Has anybody ever dynoed the two set ups to measure the differences.
It keeps on pissing me of that my 75 24V cannot keep up with my 155 3.0 24Vb (166), so i'm looking for ways to change that.
Any budget sollutions??

Lenz,

How big is the difference in performance?? For sure the long runners have more lower end torque. Maybe you should just move to the FWD setup then.

Hi Lens, I would be VERY interested in seeing the outcome of this. I have a 3L 24v 166 engine and have also wondered what the difference to the 164 engine is in relation to the complete package, not just the short block.

We were in holland last week, would have loved to see your 75.

The difference is very big, the fwd 24V goes when you push the pedal and the 75 also goes but not nearly as fast as the 155, after 4000 the difference gets smaller, the extra drive train loss is very noticable.
I now use a 1.6 gearbox wich is better but still no fwd performance.
Pancho you should have send me a message so we could meet.
I'm still thinking about how to use the fwd set up, since i will be using the idle actuator for now. Welding up the u turn or placing the throttle body on the side, any suggestions??

LENZ!

MD wrote the followings in my topic about the GTA engine project:

"The air flow is a compromise but my dyno testing shows my engine develops its normal maximum power so the theory is just a theory."

I can beat any 147/156 GTA with my setup with almost same weight.

I personally do not know the stats on these cars Lenz but my first thoughts are the obvious ones namely equivalent mass and gearing. Are the stats in favour of the FWD ?

The other factor is the rate at which the two engines will develop the same power. If one has more spinning mass to rotate (such as the drive train loading) the engines may develop very similar power at the end of the rev band and will show the same output power on the dyno but one will be a faster car than the other one.

good point MD, I never thought about that aspect.

Sorry Lenz, I had like 2 days there and went to amsterdam and volerdam then went to Brugge in Belgium, if I told the missus that I wanted to see a done up alfa 75 she would have spat the dummy. Maybe next time when I come that way with more time I would love to check it out.

The 75 has a weight benefit (1250kg vs 1320 for the 155), but the 155 has got a 156 2.5 6 speed gearbox, the 75 has got the 5 speed 1.6 box but the 6 speed still has got the shortest ratio.
The fwd climbs much faster thrue the revs than the 75.
The rubber couplings don't last and i doubt that this is the best set up so my next move will be to mount the 164 intake with the big runner and a BMC airbox, since i now use a cone filter in the engine bay, hope this will help to take care of the extra drive train loss

I decided to go with the modified 164 plenum. I made up a set of 45mm ID intake runners and then ported out the plenum and manifold plate (where the runners bolt on) to match - very little porting needed, about 1mm. The throttle and idle control positions were basically swapped but lots of smoothing work done where the throttle comes into the plenum. This setup fits under a 4cyl or v6 bonnet. Now for a paint job and I can finally put it all back together and play !!!

Daniel,

How did you bend the pipes? Were they custom bent?

Z,
I bought off the shelf 1-7/8" OD 180 degree mandrel bends and cut them to suit. Flanges were laser cut. Then had the lot HPC coated in and out.
If I did it again, I'd do it in stainless and polish it - the HPC was the most expensive part of it.

Hey Daniel,

Nice job big guy but I hope you like eatin' dust at Morgan Park when I get loose .. haha

Daniel,

can you send me some info and pics on your car pls to

rotoso at hotmail.com


I am building a very similar setup to yours and would love to hear about it.

Nice Daniel thanks for the pics, this is the way i'm planning to go too, including the place of the idle actuator.
Why make your own pipes, the original ones look the same or are yours longer.

Lenz, They are the same length as standard but larger diameter. From what I can tell, the 3.0 24v has 37mm ID runners for 210hp and 43mm ID runners for 230hp. I went with 45mm ID.

Pancho, I'll go through my hundreds of build pics and send some stuff to you.

MD, Eat your dust? Are you planning to spend a lot of time off the side of the track in the dirt ? I always found staying on the black stuff gave more grip. You know that my bigest problem is going to be the handicap that they impose on me for having an extra 1000 cc. I don't think the extra 100hp I gain from it will overcome the 7% time penalty. I think I'll just go for line honours.