Headers on S4 Spider

[rbitzer]

I've always wondered this...why do vendors such as IAP & Centerline not offer headers for S4 Spiders? They offer headers for the earler Bosch Injected spiders with Lamda sensors but not the Motronics? Anyone know why? Any reason the headers for the earlier cars won't work?

I know the cast iron 2-piece exhaust headers the S4 comes with are better than the older manifolds but I would think the custom tubular variety would still be better....

Any thoughts...

[John M]

Good question Rob:

I think they will claim space doesn't allow fitting in their tubular headers they already sell. Power steering box in the way. Probably didn't want to produce something special to fit just the 91-94. You can find headers through the overseas suppliers. I know OKP has them but they are pricey....like $550 euros or something.

Best Regards,
John M

[rbitzer]

I forgot about the steering box....its true there isn't much room with even the stock setup.

[bill_bain]

With the Motronic Spiders, Alfa went back to the pre-1975 exhaust manifold design. That design is generlaly considered to be the equal of headers for all but the most modified engines. Plus iron is much more durable.

The Motronic Spiders deelop about 130HP or so and benefit from an improved cam design and higher compression than the Series 3 Spiders. You won't gain much if anything with headers. Mild porting and polishing on the valves would be a better investiment, but it still won't be a quantum leap.

You've got the most refined and advanced Spider variant. I wouldn't mess with it.

Bill Bain
AROC Atlanta
'83 Spider
'87 Milano

[John M]

I agree with Bill on the exhaust. Not much point in messing with a good thing there. Especially since they are a free flowing type. I wish they did make 130. They only get a whooping 120. My son calls the 92 the "slow Alfa". Of course my 78 is built up so it blows the 92 away. I don't think much is going on with the cams that is much different from the late 80s series 3. Its got a VVt though. Compression went to 10:1 which helps a little. Here is a thought our two to generate some discussions:

Possibilities to generate 170 hp out of a series 4

1. normally aspirated - higher compression pistons, oversized valves, performance cams, and a port and polish if the head. You would have to chip the computer with a new timing and fuel map to prevent detonation. And another thing, balance and blueprint. My 92 engine is not as smooth as it could be.

2. engine swap - do a twin spark conversion or V6 drop in. Got to have some serious brains and know how to get this done correctly. You end up swapping motronic units, etc. But it can be done and has been done in both cases. Get into custom headers, custom engine mounts, etc.

3. boosted engine -
3a. higher boost turbo - 10-15psi. Replace pistons with low compression pistons 7-8:1. Oil jet the back sides of the pistons. Drill the mains. Balance. Intercooler. Custom headers. Duct work. Custom fuel/spark management setup. But when done much more than 170 HP. Intercooler the oil as well.
3b. low boost supercharger - 5-7psi. Remap fuel and spark in stock computer. Custom mounting bracket. Custom pulley setup. Duct work. Maybe oversized injectors. Maybe intercool the charge or oil or both.

I like the looks of 3b. If you can apply a low boost to the 2L and control the fuel/spark management with a custom programmed chip for the motronic so that you don't detonate, to me that may be the easiest road to get 170HP. And a spider drivetrain and body can easily handle that sort of output. The biggest problem in the series 4 Spider is space. We got a nice size power steering box near the brake master. We got the huge air box like on series 3. We have a power steering pump dead center top of the motor. Most have AC down in the passenger bottom corner of the front of the motor. Little room for a turbo or supercharger without pulling stuff off. My thought is to custom fabricate the PS pump bracket to include a side mount/air box side for a supercharger. And ditch the old air box as there is access to the front of the car with an air ram already in place. Kind of how the aftermarket Behr AC setups...where the compressors were mounted on spica cars....above the alternator. Then you have to fashion a tensioner pulley and decide where you getting the belt from.

Anyway...food for thought. 170HP........Then I wouldn't have to race minivans from light to light to switch lanes!

Best Regards,
John M

[backfeeder]

John M,
How about just trashing the power steering pump and looping the hoses? That should give back some of that much needed space.

[bianchi1]

..backfeeder.. would it not be easyer just to get anon power steering box/system out of an 89 and earlyer car?

[John M]

Wow...nearly 5 years ago!

I suppose you could. I love the PS especially with those heavy phonedials. I have flip flopped back and forth over what I would like to do to my 92. Alas, she is still very stock. I did chip the computer.

Best Regards,
John M

[backfeeder]

bianchi1
I would think that sourcing and replacing a box out of a non power steering spider would be considerably more work than just pulling the pump and rerouting the existing hoses. ???

[backfeeder]

John M, So the chromed Cromodoras must be on the '78?
Did chroming them add a lot of weight?

[bianchi1]

backfeeder, just thought it might save some wight, and removing the steering system is not all that hard,i have it down to 15 mins. to remove and 20 to instale a 84 steering box..

[backfeeder]

Cool! Thats good to hear. Can you tell me more about the process?
I'll be happy to call up someone like APE and try and get an older steering box.

[John M]

Quote:

Originally Posted by backfeeder John M, So the chromed Cromodoras must be on the '78? Did chroming them add a lot of weight?

[backfeeder]

bianchi1, I just read the instructions you wrote in the Burman/ZF steering box removal/installation/interchange thread. Is that what you're suggesting for me to do also? That ZF steering box replacement does on the surface seem to be a much larger undertaking than a 35 minute turn around time. For instance just removing the steering wheel takes some people days to do. I'm more fortunate but it did take me 30 to 45 minutes to pull my steering wheel when I replaced it with a Nardi. I will go ahead and replace the power steering if I can somehow retain my A/C....Just cannot survive without it here in Florida. Either way, I am grateful that you have taken the time to shared you experience and expertise.

[backfeeder]

John M,
Thank you for follow up. I hope that I'm not becoming a PITA by asking a couple of more questions. I really like the idea of chroming the wheels. I'd like to know if you had them done locally or shipped them off and at what was the cost?