New exhaust...too loud

Well, I finally got the IM on the road, with the new 2110, 44 DCNF Webers and new custom exhaust. DCNF carbs, 911 shroud and center pull linkage...what a hassle! The car goes great, with the 44s, but when I boot it, boy is the exhaust loud. It's okay just cruising around, but all hell breaks loose when I floor it! I think the Magnaflow is just a bit to 'free flowing'. Would a resonator, at the tailpipe, help quiet the muffler down? If not, I may have to go to a more restrictive (meaning more quiet) muffler. Interestly, there was a big difference in noise when I switched from the Weber 40s to the 44s. The exhaust system sounded nice with the 40s, but seems too loud with the 44s. I think a lot of that noise is intake noise from the 44s. I noticed that one of Henry's new cars had plastic air cleaner covers (looks like a Tupperware container turned upside- down). Anyone know what they're for? Would that help quiet down the intake noise?
Ron


(Message Edited 3/31/2003 7:39:39 PM)

Ron,
I believe they are rain shields

They are rain shields and 1) they restrict air flow to some degree, and 2) on an IM you really don't need them unless you use a hose to wash your car and are very careless.

One of the problems with having a custom exhaust made is that it may turn out to be obnoxiously noisy when you put your foot down. If the Magnaflow is larger than 2 1/2" in/out you might try going to a smaller Magnaflow. Or if it is a 2 1/2" unit try a Borla or Dynomax.

Ron, I sometimes unbolt my Supertrapp and put on a set of 911R racing megaphones...and a set of earplugs! Its music!

Brian

I like a loud exhaust (drowns out the loud 911 fan noise). It just borders on the line between "loud, but it sounds sooo good", to "Oh boy, this is too damn LOUD". As I said in my inital post, it's only 'over the top' when I floor it. That's why I thought that a resonator might quiet it down a bit.
When I put the 911 fan shroud in the car, I had to cut out some of the fiberglass rain shield under the grill. Consequently, water drips directly on to the fan and is spun to one side of the engine bay. Luckily, not a lot of water leaks in.
By the way, all this talk about mufflers blocking valve covers and causing so much extra work to get at the valves is just talk. Took me no more than 10 minutes to drop the exhaust on one side to get at the head, so I could try out some 1:25 rockers to help liven up my Engle 110 cam. And since I adjust the valves no more than twice a year, it really is no big deal. I can actually adjust my valves without dropping the muffler, but it is tight.
Ron

By the way, Brian, you just can't compare the sound of 911 and the sound of a flat four VW engine. The 911 has that distinct sound, a cacophony of mechanical sounds. Nothing else sounds like it. I still remember, back in the 70s, watching racing 911s go by me, flat out, along the the straight-a-way at Westwood racetrack. What a sound! Forget the stereo. The real soundtrack is controlled by your right foot.
Ron

I got a ride in my buddies 1969 911, that engine sounds incredable. I'm sorry to say (I know I'll get hell for this) that my car will never sound that good. Flat fours have a great bark to them but a 911 has such an incredable whine to it that it can't be compared to.

As for the muffs being too loud, try a resonator, that will help a bunch!!! The resonator takes the high pitch noises away and leaves a cleaned up toned exhaust note, they are also inexpensive.

J-P

That's true, JP. A resonator is about $50 up here, but a new more restrictive Magnaflow, Bora etc., would be at least $150. Plus, the resonator just bolts on. I agree with you on the sound comparison between a VW four and a Porsche six. No matter what you do to a VW exhaust it will never come even close the the sound of a 911 six.
Ron

Ron, if you just "bolted on" the 1.25 to 1 rockers to replace stock rocker arms you might want to check both your pushrod length and all of the other related things that could be a problem when increasing rocker arm ratio. Everything is probably OK but it's better to KNOW they are OK than simply HOPE they are.

I changed the push rods. The ones I had in the motor were too long.
Ron

When I had the motor done I had the transmission done too. Well, the transmission is not right and may have to come out (my builder's problem, not mine). At that time I may spilt the case and change the cam from a Engle 110 to a 120 or 125. Might be a good time to get the heads done too. (The trouble with joint bank accounts and master cards is that I can't hid anything from the boss. Is it just me, or are the rest of you also nut(car) cases with rational spouses? I guess it's a good thing. If my wife was like me...we'd be living in the backseat of our car...but boy, would it be a nice car!)
Ron

Ron, don't feel like the Lone Ranger. I'm just lucky my wife loves horses as much as I love cars. I think I'd rather live in my car than on a horse.

Don't choose a cam until your heads are done, then ask the guy who ported them which cam to use. Or, tell him which cam you want to use before he does the work. Cam/ports should work together.

Ron: Who built your motor? Darren Krewenchuk lives in Burnaby and is petty much the man for air-cooled VW motors for this part of the world. He is quite helpful and worth talking to.

Where do you live, Bruce? Darren built my original motor-a 1776. I wanted to run heater boxes and at the time the only thing available were 1 3/8" heater boxes...so I settled for a mild 1776. The power was okay and I was happy with Darren's work, but I wanted more go. Also, my 911 fan sucks more power than a regular doghouse shroud. I ended up having a fellow who lives in Chilliwack (only 15 minutes from my house) redo my motor and upgrade it to a 2110. He's very competant. He drag races a 10 1/2 second (1/4 mile) beetle and really knows his stuff. He's been building high performance VW motors for at least 15 years, so I trust his judgement when it comes to cams etc. The fellow that will do the heads is the same guy who did my builder's race heads. I'm hoping for approximately 140 hp. I don't want to overdue it, since I put a lot of highway miles on my car each year (a lot is a relative term...around 5000 miles a year, which is about 1/3 the miles I put on my pickup truck).
Ron

Ron: I live in Vancouver a few blocks from Intermeccanica.

I was looking to tone down the sound of my megaphones and CIP suggested a set of Harley baffles. They said they are heftier than the aftermarket VW stuff and when I checked on Ebay you can usually find a set for $20 or so as most Harley owners remove them.

Brian

Bruce: I lived down in that area when I went to university...back in the early 70s (those hippy-dippy days). Lived just off 4th Avenue-a few blocks east of Burrard.
Brian: Monza exhaust systems: www.pacesetterexhaust.com/tips.htm
Nice selection of resonators in various styles and diameters. Harley baffle sounds like a good, inexpensive choice too. I think I'll stop in a my local Harley dealer and check them out.
Ron

Ron: If you are looking for Harley baffles, try an independent Harley shop instead of a dealer. There are a ton of aftermarket parts available that the dealers do not stock and the price will be MUCH better. WWW.jpcycles.com are good people and have an online catalog.

Chuck

Thanks Chuck.
Ron