I'm picking up a 74 2.0 car for Sandy. It is coming with a 75 engine. I started thinking about the H.E.'s and the difference in years. I'm not going to use the air pump stuff.

1) I don't recall is the 75's have a cat. Anyone have a photo of a 75 Exhaust from under the car?

2) I have a 72 steel exhaust. How much different are the 1.7's from the 2.0's?



I think it would be cool if we could get a thread with photos of the different exhausts and how they perform.

Header conversations are cool too.

The 75 HE's and the early 1.78 and 2.0 are completely different. I've never owned a 75 or later, but I've been under a few. I don't have pics either unfortunately. Got PET? Look in there.

No PET. Are you saying the 75 are the short set with CATS? Never owned newer that 73 and never a 2.0

Only CA 75's had cats (I think). I know nothing about cats. You can put any set of HE's on any 4 cylinder 914 if you have the right parts. PET will tell you the difference. You can view it on the Porsche site even these days. Someone posted a link in the last day or two. In Mary's thread I think.

OK cool, that helps. This is a 75 2.0 engine so it may have cats. I think the inside diameter is smaller with the 1.7 than the 2.0's I'm really just wondering if I'm going to have to search for a 2.0 H.E. set or if I can use what's on the engine. I will know what I have in a couple weeks.

Didn't the 75 and 76 have the funny triangle flange instead of the 2 side by side?

I do know first hand the 1.7 is different than the 2.0, and even the muffler and hanger are different.

What were you trying to fit? Got any photos?

Rick, I just removed a 75. Its sitting on the floor, I can get a pic and post it tomorrow. The ssi's are all the same diamater inside. The 75 he's will rob you of signifigant HP.

Cool, This will help alot. So your saying the inside diameter if all H.E.'s are the same or all the Stainless sets are the same?

Then are you saying the 75-76 H.E.'s rob HP? Because? of the cats? Can you remove the cats and get the HP back without replacing the entire system?

We don't have inspections here in MN. So IO'm not planning on running the air pump stuff.

Just a bunch of 1.7 and 2.0 stuff on the ground right now. The 1.7 come out higher at the end and has a bend in it. The 2.0 has bigger tube and come straight out. It's really raining out, so cant get pics right now. I do not have the later units at all.

Oh, ok, I think I'm catching on. (just a little slow today )

Post what you have when you get a chance.

The late he's are made different. They have a piece that goes forward from the header then makes a u turn, and bolts to the he's.

SSI's are the same 1.7 0r 2's

Thanks Curt, I'm going to have to see if I can find a photo of the 75-76 system.

Thanks for the clarification of the SSI's

Should be on the PET.

I'm pretty sure there's a post in the Classics forum with pics.

The 1.7 and 74 1.8 use the same exhaust. The 73-74 2.0 is a different one; the heater parts interchange with the earlier exhaust but the muffler and muffler hanger and heat exchangers are different and not swappable.

The 75-76 exhaust is different, and restrictive, and pretty much none of the parts interchange to the earlier setup. But you can swap on the whole exhaust and heater setup from an earlier car onto the late cars.

--DD

Thanks Dave! I'll try to find it in the Classics thread

Not all 75 or 76's (mine's a 76) have the cats. It's my understanding the cats were for CA cars. I would you could easily find someone in CA(without the cat set up) that wants to DEQ thier car would swap in a heartbeat.

Man! I wish I knew this earlier! I had a whole 76 2.0 (HE's included) tipped on it's side in the back of dad's pickup! ...and I had my camera out!

We had quite a converstion about the 75-76 exhausts. I will try to take some pics tomorrow.

Yup, cats are for Cali cars. I have a catalytic converter off of mine in my attic.

Did you replace the entire exhaust or just remove your cat?

I guess I'm wondering if you remove the cat and fad a "test pipe" as the chevy call it, is that enough to recover the hp lost through that system?

That photo would be a big help. Thanks.

I did a search last night for the PET but didn't find it.

Here ya go Rick.

sadfdsa

Oh...now I get it....... That will never do. I'd be better off with 1.7 h.e.'s than something like that.

Thanks for that photo. I have never looked under a 75-76 car.

Bingo!

They also increase oil temps.

Rick,
Replace exchangers with 1.7/1.8/2.0 from any pre 75 car, muffler hanger, muffler and exchangers are a matched set. 75/76 cars hanger is unique to those years. As I recall you'll need to replace just some of the heater tubes. Pull all the air injection stuff.

Now, the ECU, MPS and throttle postion sensor(fuel overrun) is unique to the 75/76 as well as the TS2 I believe. Your car will run lean and you'll need to richen the mixture a bit to get it to run correctly, especially at low end rpms. The ECU knob will usually not richen the mixture enough for the low end circuit. I tricked the ECU by adding some more resistance inline with the TS2...works great, but you may get some flack from some that say it doesn't work. I've done this mod a couple times now with great succes. PM me if you're interested.

Good Luck,

Hey 4kids, Can I copy your link to the google 914 search? Works way better than the one here.
Sorry Andy

The 75-76 HE's used the J tubes same as a bus which robbed HP by its crapped design, no scavenging of the exhaust pulses.
75-76 run the 043 MPS same as the 74 2.0L so no need to adjust that. I would run a LM1 on the engine once everything is done to check the AFR.

There is a good pair on Samba now for $350

If I needed some I would buy them.