slim72914
Oct 11 2007, 08:49 PM
Im going to pomona this weekend for the swap meet(hopefully). And I need exhaust for my 1.7. How can I tell whats what if I see anything in the swap meet other than assuming the seller knows what it came off of??
stateofidleness
Oct 11 2007, 08:55 PM
correct me if im wrong but ill take a stab at it:
i believe (most likely wrong) that the 1.7 and 1.8 exhaust is interchangable and it will have 2 outs on the heat exchangers.. the 2.0 has 1 out on each HE.
ok.. go ahead and correct it lol
jd74914
Oct 11 2007, 09:03 PM
WRONG . . . the 1.7/1.8L HE's curve up at the end. The 2.0 HE's are straight. Without comparing the 2 mufflers I don't know how easy it would be to tell the difference between them.
The 75/76 2.0 exhaust has one outlet on each HE but you don't want that, its evil.
stateofidleness
Oct 11 2007, 09:05 PM
well it was a feeble attempt... lol
i admit defeat
i think i was thinking of the years instead of engine size.
what's wrong with single outs on each side? serious question
jd74914
Oct 11 2007, 09:11 PM
There wouldn't be any problem with them, except that the 75/76 HE's flow worse than the early units which severely impedes performance.
It was a good thought.
slim72914
Oct 11 2007, 11:20 PM
QUOTE(jd74914 @ Oct 11 2007, 08:03 PM)
WRONG . . . the 1.7/1.8L HE's curve up at the end. The 2.0 HE's are straight. Without comparing the 2 mufflers I don't know how easy it would be to tell the difference between them.
The 75/76 2.0 exhaust has one outlet on each HE but you don't want that, its evil.
So then are the mufflers from a 1.7 and a 1.8 interchangable? or is there a difference where they bolt to the heat exchangers as well?
jd74914
Oct 11 2007, 11:45 PM
Yep, the 1.7/1.8 mufflers are interchangeable.
A 2.0 system will bolt onto your car too if you get the HE's and the muffler.
stateofidleness
Oct 11 2007, 11:45 PM
from what ive gathered.. you can put any kind of muffler on any size engine as long as it matches to your heat exchangers
if you have early exhaust it will have dual outs on each side... so then the muffler that will fit it will have to have two outs on each flange
same for the late models.. one out on each side.. one out on each muffler flange
jd74914
Oct 11 2007, 11:50 PM
Um, thats not quite right, close again though.
All of the early mufflers (both 2.0 and 1.8) may bolt up to the same HE's, but they might not fit into the car. The 2.0 muffler sits lower than the 1.7/8 does. That's why you can't put a triad collector/muffler on your 1.7/8 heat exchangers.
stateofidleness
Oct 12 2007, 12:04 AM
Rand
Oct 12 2007, 12:48 AM
1. Just to confirm: ALL the exhaust systems are interchangeable with ALL the engines, regardless of year and displacement, right?
2. Clearly the 75/76 2.0 is the worst exhaust system of them all. But how do the rest compare for flow / performance? Is there a significant difference?
3. Did any of the 1.7s and 1.8s change through the years?
4. IIRC there is a difference in the ID between some of these systems. Which one(s) are biggest? Seems to me I saw a pic showing a 1.7 system having the largest ID. If that's true, wouldn't it be the most desirable of all, even on a 2.0?
rhodyguy
Oct 12 2007, 07:46 AM
pictures coming after the sun rises.
k
orthobiz
Oct 12 2007, 09:24 AM
Somebody please NAIL newto914s unbelievably wonderful visual guide to exhausts and heat exchangers:
http://www.914world.com/bbs2/index.php?sho...&hl=exhaustPaul
Dave_Darling
Oct 12 2007, 10:27 AM
If you're talking the stock "sausage" mufflers, the 1.7 & 74 1.8 will have the inlets roughly near the middle (top to bottom) of the muffler, while the 73-74 2.0 muffler will have the inlets pretty much at the bottom.
Cheesy ASCII-art illustration:
1.7 == -O
2.0 == _O
The 75 1.8 used the same exhaust as the 75-76 2.0 did. Which is pretty bad, what with that really tight 180-degree bend at the front and the long crossover at the back.
--DD
Cevan
Oct 12 2007, 10:35 AM
QUOTE(jd74914 @ Oct 11 2007, 11:03 PM)
WRONG . . . the 1.7/1.8L HE's curve up at the end. The 2.0 HE's are straight. Without comparing the 2 mufflers I don't know how easy it would be to tell the difference between them.
The 75/76 2.0 exhaust has one outlet on each HE but you don't want that, its evil.
Why evil? Because they are more restrictive in terms of exhaust flow? Because they make it harder to adjust your valves?
I'm looking for 2.0 SS HEs. Did they only make them in '73 and '74?
For anyone who has put them on a '75 or '76 1.8, were you able to feel a difference in power?
rhodyguy
Oct 12 2007, 10:56 AM
porsche NEVER made ss hes for a 914 as far as i know. aftermarket product. one major benefit of the backdating, whether 1.7/1.8 or 2.0 is the exhaust options/choises. the late ones weigh quite a bit more, convoluted design, multiple connection points and gaskets to fail. even a resonably priced set of 1.7/1.8s, is a better way to go. start saving and find the best set of he's you can afford. i've sold 3 sets of ss 2.0s in the last few months. they went rather quickly.
k
davep
Oct 12 2007, 10:57 AM
Don't forget the muffler hangers are also different.
Complete exhaust systems are roughly interchangeable, where complete means from the copper washers in the head to the tip of the exhaust pipe and including the hanger.
The best stock system is the 73 & 74 2.0 especially with SSI heat exchangers. This will fit on any 914/4.
914werke
Oct 12 2007, 11:19 AM
QUOTE(Dave_Darling @ Oct 12 2007, 09:27 AM)
If you're talking the stock "sausage" mufflers, the 1.7 & 74 1.8 will have the inlets roughly near the middle (top to bottom) of the muffler, while the 73-74 2.0 muffler will have the inlets pretty much at the bottom.
--DD
Dave its interesteing that your chariterization of the OE mufflers as a "sausage" vs. the more commonly used nickname "Bannana"
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