Magnaflow Catalytic Converters '82-'89 Spider

[smestas]

Here is a link to a complete system that will work on a '70 spider.

MAGNAFLOW Exhaust Systems Have Arrived !!!

PM or email if you are interested.

[Ripstinger]

I just put one of these in my 89 Spider. The fit was pretty straight forward, the length was right and the O2 fit, you won't be able to get a socket on the O2 but there isn't much recess so a wrench works just fine.

The problems are in the flanges in my case. The rear flange where it mates the middle section is a good deal larger than the stock flange. They provide enough slop in the bolt holes to make it work but it is less than ideal. The flange where it mates the manifold needed to be worked, the holes were off about 1/8th inch all the way around and the angle of approach interferes with the steering column. I had to open the top flange holes quite a bit to get enough play in the approach for a match. And even that only left me with a 1/16th clearance from the steering. The exhaust currently rubs on a right turn. I'm still working on that problem.

[jclark]

Quote:

Originally Posted by smestas Here is a link to a complete system that will work on a '70 spider. MAGNAFLOW Exhaust Systems Have Arrived !!! PM or email if you are interested.

[andytitterton]

Any comments regarding removal of the catalytic converter and running the car without?

Background first though - I'm in the UK and the whole exhaust was shot when I bought the car. I am not obliged to fit a catalytic converter because of the age of the car, and since they are quite expensive, I bought a standard exhaust system instead. I read up on the Lambda sensor, and since this measures the percentage levels of gases in the exhaust and feeds the signal back to the ECU, I welded it into place at an appropriate point the correct distance from the manifold. The car seems to run ok, but should I be leaving the Lambda off altogether or not?

While I have your interest, if anyone in the USA has a right side fender liner that they could post to Illinois, please get in touch.......

[Tifosi]

If you've got EFI, then you definitely want the lambda sensor regardless of the presence of a cat converter.

The sensor tells the EFI computer what it needs to know to adjust mixture, and without it, most systems revert to a significantly rich mixture across the board in an effort to not burn the engine up.

With it you get:

Stoich mixtures during closed loop operation
More accurate mixutre at idle (even though that's an open loop function, the ECU recognizes that the sensor is present and functioning and uses an appropriate fuel map instead of defualt 'emergency map')

What you get without it:

Slightly to horrifically over-rich mixture at all reve ranges and throttle positions

No stoich during cruising (resulting in a significant drop in miles per gallon)

Loaded or nasty plugs making for worse runing yet.



Do yourself a favor and leave it in there, really.

[andytitterton]

Thanks for your comments. Looks like I'm doing it right. I've had to mount the sensor in the section of pipe used for two cylinders rather than four, because otherwise it would have been too far away from the exhaust manifold, but I can't see this being a problem since it works on a percentage basis rather than the actual amount of gas.

[Tifosi]

Collecting from all 4 would definetely be better, but as yours is (should be anyway) the heated version it's not totally out of whack, it's just not the ideal way of doing it.

Prime advantage of sampling all cylinders is getting the better average reading. Worst case scenario would be you could drop one of the cylinders not being sampled and the system would never know the difference because the sensor readings would never pick it up. (then that dead cylinder ends up with whatever a too rich or too lean mixture does to it over time)

Of course now that you've got the bung in, its a bit too late to change, but in the future you'll likely want to get that reconciled. (the heated elements arent as evil in their requirements AFA how close they have to be to the head, which is the real issue associated with the single wire versions: they cool off and stop sending signals if you're not actually moving down the road at X pace)

[Alfonse22]

I will be needing a new cat and O2 sensor when I bring my '89 spider quad out of storage in the Spring. I was about to go to Centerline or IAP when I found Simon's post. Free flow is good and I want one.

But, Simon, can you address Rip's concerns about the flanges and how the fit? I'm not necessarily one with patience for cut-and-paste hardware.

[elle va]

Just finished looking at the pics. Looks great. Do you have one that will fit my 87 spyder veloce? Can this be fitted without having to lift or move the engine??

[alfa-sport]

Alfonse22 - I sent you a PM

[the_sicilian]

so we really dont think these can fit a 90? isnt the exhaust manifold the same? in fact, my block is even an 89 and the body as well. does the motronic really affect my exhaust at all?

are you sure this cant be fitted on an S3 1990 Spider? (theres some confusion at times that the 90 is an S4 since some 91 models have 90 body tags. but the 90 was an S3)

i am interested in purchasing, please advise. thanks alot

[Elio Comello]

Siciliano, the 90 S3 Motronic uses the S4 exh. manifold which is "better", but ir will require that you use an S4 downpipe.

Elio

[Slash]

Simon,

I apologize for not purchasing one of these systems as I said I would earlier in this thread. My cylinder head rebuild was an unexpected and large expense.

To make up for that, I will take advantage of your subscription program as soon as I can. Thanks for everything!

[Oski_Bear]

Is there an update on the misaligment of the holes to the manifold and rear pipes?

[smestas]

Sorry to those who have been asking. As of right now I do not have newer sections and still have two of the original parts left in stock. These two pieces are as previously mentioned slightly off where the flange meets the manifold. It can be cured with some drilling but not a perfect fit without some modifying. See the image below. Anyone interested in one of the last two pieces send me a PM or email.

As far as going forward we are planing on remaking this part but as a whole Hi-Flow system from the manifold all the way back. More on this later.