Engine sound/upgrade question
 

Hi yall..

I had an early porsche 2.0l with weber carbs in it I sold. What I want to do is upgrade my 76 to more HP but I want that classic early porsche sound. I can only assume this low end rumble came from the webers (correct?).

That being said.. whats a good route for me to go keeping a tight budget in mind.. I assume the best bang for the buck would be to sell my motor (which appears to be totally stock including tensioners and crappy exhaust) right out of the car.. its relatively quick, no smoke can only assume its gonna have good compression based on performance, lack of smoke and idle characteristics).. Probably1500- $2k in this economy??

But then what route do I go to get that awesome sound?

I assume btw that my motor would require cams to go to carbs which would be really expensive to do?

Also, note my car does not require inspection in this state as of next year.. she turns 30 which is the cut off point.

Third gear needs finesse in my 915 trans.. can be shifted with no crunch but requires careful upshifts which includes either a double clutch or a careful match-rev.

This is getting more expensive as I think about it lol..

I just miss that classic sound and want it back in my life.


Regards.

You'd get more of "that sound" by changing the muffler. Get a pair of SSI heat exchangers and an early muffler. It's a much cheaper option than swapping the engine, which won't necessarily do anything to change the sound. Fitting the engine with carbs will change the intake sound but that isn't what you are after.

JR

So, my assumption is dead wrong then.. it was NOT the webers but the exhaust?? Hell if thats the case Im all over an exhaust swap since mine is nothing but a motor baker anyway... (thermal reactors are still in place).

You sure about this? I thought for sure it was the intake that was letting me hear that low end rumble.. it also had those small K&N's on it fwiw..

If thats the case I'll throw some nice early heat exchangers on it and I guess if the muffler was part of the sound then I'll look for a new muffler.. I dont see a need to do SSI's here in the south..

Early 911 mufflers were a lot louder than the ones that followed. Anti-noise legislation progressively got more restrictive, to the point that most modern cars make almost no exhaust noise, other than a characterless hissing sound.

Webers will make more intake noise than CIS, but that's not the sound you hear when a 911 drives by. I suggested SSI's because they offer the same benefits as the early heat exchangers and they are contructed better. If you can find some early heat exchangers that are in good shape (not rusty) then go ahead and use them. I'd bet that route will be harder than finding a good used set of SSI's. Note that the muffler is the main goal here and not all two-in single outlet mufflers will sound the same. If you want a lot of noise, a two-in, two-out muffler will give it to you...

Have fun,
JR

Thanks for the help.. Im not looking for noise.. in fact I HATE the droning sound at freeway speeds some "sport" mufflers can make. I am about as far from a ricer as you can get when it comes to my sound tastes.. My 69t had a low end rumble that was not annoying as hell.. THAT is the sound I like..

Im glad I posted this as I think I was gonna go down the wrong road..

I need to take care of my thermal reactors before summer anyway... and I hear that early exchangers will buy me a few ponies in the process.. so it makes good sense all around..

I did some looking in the classifieds.. not a ton out there but patience will pay off..

Wonder what the difference in design in between my 2in 76 muffler and an early 2 in muffler like the one that was on my early car.. hmmm things that make you go hmmmmm ;) Maybe there is a loop inside the newer designs..

Im tempted to pick up an early muffler and just throw it on so I'll know.. would take about 15 minutes to install one I bet.

I can't answer that question directly but there had to be quite a difference. If you listen to an early car, it is much louder than a '76. In fact, I find the '65-67 cars to sound vastly different to the later long-nose cars.

As you say, it wouldn't take long to find out... the challenge would be to find an early muffler in good condition, as opposed to an aftermarket replacement muffler.

JR

JP,
Let me know how it goes on removing the heat exchangers. I've got the same issue, but after reading posts of what a pain it is to remove them I chickened out.

Thanks.. I'll do some looking around..

In regards to the exchanger swap.. I'll let you know how it goes.. I have a lift in my garage which will make it easier but Im not looking forward to removing the rusted nuts.. My initial thought is to use a air tool to cut a piece off of each nut effectively damaging a very small area of the threads in each stud... be a hell of a lot better off than breaking one off... I need to do some searching and see what others have done.. I have replacements for the thermal reactors that just bolt up to the existing heat exchangers but without the additional HP upgrade id get from SSI's or early exchangers my motivation has been very low....

To get the nuts off use heat as in get them "cherry red" with a torch. I tried getting mine off using Kroil and went right to the torch. All came off easily with the heat. New nuts and use copper anti-seize when you put the new ones on.

Glad I invested in acetylene. :) I'll try that first.. I've done this enough time to know a simple penetrating oil is a practice in futility.

How about trying a pre-muffler / Bursch exhaust combination before you remove your exchangers? It's a cheap route and you might like it.

I dont know what you mean... besides the exchangers pretty much have to go because the ones with the reactors (which I have) supposedly cooks the 2.7l..

But Im curious as to what you are refering to here...

He's referring to a later style exhaust configuration. Not what you have, or want.

JR

BTW.. it appears as though an early muffler will bolt up but the tip will be at the wrong angle.. I suppose nothing a little cutting and welding wouldnt fix but still.. not a direct fit... if someone knows different chime in.

OK please ignore my suggestion. After re-reading your post it seems 'droning' will be a major issue. But it does sound good. That's what's on my car when I got it. Good luck!

The thing is, his car has a different exhaust setup than yours. His system doesn't gather the exhaust from both sides at a common point on the left side of the engine. To do the a system like what you suggest, he would first have to add the heat exchangers that an SC or Carrera has as stock, plus the crossover piping for the right side. If he changes the heat exchangers, he's better off using the early style.

JR

So after some scraping and grinding and so on.. my muffler seems to say:

Bischoff 911 025 00 (and it looks like the 2nd 0 in 00 was replaced with a 2 or visa versa at one point) / 74

So 911 025 00(2) / 74

Trying to find info on it but coming up with very little so far.

JR, thanks for clarifying... did not know 76's are like that.

Hey,
I removed my thermal destroyers and replaced them with a set of "headers", they bolted right up to the rest of the OEM exhaust system. It was a good intermediate swap until I found some used SSIs. I also installed a Leistritz(sp?) muffler with a 3" single outlet, no cutting of sheet metal required. The sound is awesome, and the power is way up!
My exhaust system came off with out much drama.
eric

Thermal destroyers.. I like that.. :)

I noticed something last night with my setup.. It actually sounds nice at idle (dont really give a crap about that) but when you get on it.. nothing.. its a non-event.. so its the opposite of what I want.. when I got on my 69T she rumbled like a v8. Real LOW tones...

I think Bursch 2 in 1 out is what you want. Or fabricated 2/2 Dynomax muffler.

Question: why? Im about 90% sure my muffler was stock on my 69.. wouldnt I want that?

Bursch mufflers sound a lot different than the factory ones. In my opinion, this won't give you the sound you are looking for. I have no idea what a Dynomax would sound like.

I'd suggest that you keep looking for an early 911 muffler. Given that there have been a bunch of different mufflers used over the years and I haven't unraveled the meanings of all of the stampings on a given muffler, finding the one you want may take a little effort.

Happy hunting,
JR

Yep.. thats the plan.. there is one kinda beat up in classifieds.. wonder if it would be worth picking it up.. I have a welder and acetylene torches so not much I cant fix. I also bought a set of stock heat exchangers.. they should be here in a week or two.

I suppose I should hold out for a good muffler... the inner working may be all bent and messed up which could cause leakage.

Bursch sucks, IMO. Do what everyone has been suggesting, get some SSI's-they are the best route, period. It is then up to you on muffler choices. If you want that early crisp sound, get a stock banana muffler. If you want it a little louder, get a SS dansk muffler that has what I think is a 3 inch outlet (2 in, one out). If you want it even louder, go the MB route, 2 in, one out. If you want it to scream, get a dual outlet from dansk (tips come out the sides). And if you really want to piss the neighbors off, get the dual outlet sport muffler where the tips come straight out the back about a foot, then cut 6 inches off. If you want to go the custom route where you will need a muffler shop to weld it all up, go the dynomax, magnflow route which gives you a unique, but great sound.
When you are ready to install the HE's, post back and we can all help with the tools and procedures on how to get the old ones off.

Thanks.. but due to budget constraints and a lack of need for pretty shiney stuff under my car I went with stock early heat exchangers.. based on what I read SSI's would not offer much better flow.. regardless.. this is what I chose.. I'll sand blast em and give em a high temp paint job when they get here.

I have a lift which will help with the removal but it looks like its gonna be a bear.. I may just cut off the thermal destroyers to get them out of the way.. I have a bad back and dont need the crap in my way when I go to do this.. Im guessing heat up each nut cherry red and take em off should be the procedure.. I may start this today or soon anyway because if I wait till the exchangers get here I will rush and break a damn stud.

I was able to get 11 of the nuts off by just spraying them with PB blaster every other day for a week, but two of the studs came out as well which is no biggie as you can get them at any good hardware store. One would not budge even with heat, so I dremeled that one off. If you have no need for the old ones, saws all the hell out of them. To install, I used a swivel 13mm socket attached to a long 1\4 extension, attached to a 1\4 to 3\8's adapter and a ratchet. This by far is the best tool to get them off if you have the old style HE and installing the new nuts as I did not use any other tool besides a long Allen socket for the barrel nuts.
Do not forget anti-seize and if you have some high temp sealant, use a thin layer on the new gaskets so they stay in place while mounting the HE's
Good luck

classic early 911 sound = stock muffler; used will be cheapest so call a salvage yard near you

Monty is more rumbly and pretty spendy now, but Ben can surely fix you up with whatever you want

a dual cowhorn style will be louder; no 'extra' power

sport muffler can add a few but quite loud and you have to tune for it

So I'm done with phase one.. early heat exchangers:

My findings after about an hour of driving:

More power above 3500 RPM.. substantial? Seems like it anyway.. revs faster.

Exhaust note: Crisper, more defined.. can hear each cyl fire.. lower note..

But still not my 69t.. so on to phase 2.. early muffler....


http://forums.pelicanparts.com/uploa...1269793919.jpg


Nuts came off with heat.. had to work some of them slowly and reheat a few times.. patience is required.. few studs spun out but no big deal.