Hello,

Many of you probably think 'please not another muffler advice' thread. Yes, you are absolutely right, but after reading through several threads and Google research I still have no solution for my problem.

My Vette is a 84 with 350 block, ported alluminium heads, 454 TBI injection, cam 236/241 - lift .552/.547 and mid-length headers (biggest one that fit - 3") with a custom stainless steel exhaust system with stock diameter size - cat and 2x straight-through mufflers (no name).

The engine mod happend 5 years ago and in the past I was happy. 90 decibels idle and the outside sound pressure is now too much, especially at night in narrow streets (It seems I'm getting older). This is the reason why I start to avoid driving the vette.

When I read threads they handle either the muffler options for stock engines or 'you should have to life with the loud cammed sound'.

I already checked the usual Vette parts shops and was wondering, what happend to all the C4 exhaust options like 5-10 years ago?

Sacrificing few hp is no problem for me! Is the Walker quiet-flow 3 muffler too restrictive? Any other options?

Thank you so much in advance!

 

walker makes good exhaust systems, probably one of the few companies who actually make ALL of the exhaust systemes really. i used to live a mile away from a walker test shop, miss that sound of dyno's revving out all day to be honest. walker dynomax used to be a really great sound with performance to back it up. not sure if they make em anymore

 

Corsa

 

cat back, is not an exhaust system... imo, that is what they call fart can exhaust i think. but you know how opinions go i guess

 

I’ve been very happy with the stock LT1 system with an x pipe added and the resonator swapped for straight pipe. No drone, barely louder than stock, throaty sound that opens right up with throttle. Can be retrofitted to any C4. That said, I‘m cammed and only a trained ear could detect it with the stock mufflers, so if you need to hear that chop this setup may not be for you.

 

Man I want to here more about another TBI 84. Is it still a crossfire etc etc.

I really do think exhaust note is in the ear of the beholder and if it was me I would discuss options with the local exhaust shop if you trust them. My car had X Force mufflers when I got it (but I don’t know if they are available in the US). When I did the exhaust the exhaust shop said give them a go and if you don’t like it we can make other suggestions.

 

I think that you'll get what you are after with Walker.

Summit Racing has some in-stock. If you find a better price, just call them and they will beat it. :-)

https://www.summitracing.com/parts/w...model/corvette

 

Thank you for your input, probably I'll try the Walker quiet flow and will let you know how it worked out.

No, it's not a crossfire injection anymore, as it was not really possible to tune it. Back when I started planning the engine rebuilt, this renegade manifold wasn't available at Summit (https://www.summitracing.com/parts/ems-msren-100p). One of my first mods were the mid-length headers, but unfortunately the car didn't ran very smoothly because the old 84 ECU couldn't handle it. So I already installed a programmable ECU which could handle two injectors. As crossfire was no option anymore, I switched to a 454 TBI from a 90ish truck with only minor changes of the wiring harness, installed bigger injectors and increased the fuel pressure by a bigger pump.

 

Yeah that’s not a bad way of going. I was fortunate enough to get a decent Renegade and I used a Dynamic EFI EBL flash II to tune it. In the future I’ll probably convert my circuit racing 84 to a Holley Sniper system or something similar it currently has a 750 double pumper and a Victor Jr intake.

 

Hello,

If I were going to I buy another exhaust system I would consider the Chambered Exhaust system. They have no mufflers to have hanging out the rear and they make power while sounding good. You can buy them with different sound levels. Mine are like side pipes noise wise but it all goes out the back while I am cruising. I bought my Chambered Exhaust systems from Allen's Stainless Exhaust in Indiana. I also have a Chambered system on my C4 which makes the tame L98 sound like a "real" engine. It sounds far more intimidating with the current sounds and has no drone as I replaced the Catalytic converter with a High Flow unit. The Gtech indicated that it gained almost 14 hp from the exhaust change.

Hello again Greg!

You can't go wrong with the Holley Sniper if you decide to buy one. The folks who sold me my system would be the best bet, even in your case. They offer support AFTER you buy the system. They have an expert on staff who will answer your questions right away. The one thing you need to be careful of is the placement of the throttle body and which model you use. The standard Sniper is an east-west orientation (a bit wider) whereas the Sniper Stealth looks just like a Holley Double Pumper. I use an original L88 hood on my C3 and I don't think I could have used the standard sniper with it's limitations. My base plate for the air filter is a drop base but would not clear anything unless shaped like a carburetor. The Sniper would not allow me to use this base plate. It does however fit perfectly with the Sniper Stealth. The Super Sniper Stealth is $1247.95 where as the one I bought is selling for $1100. The "Super" version offers several inputs and outputs that are programmable. I wish I had bought the "Super" version as I could easily use the extra inputs and outputs that I could use. The Holley uses the newer CAN-Bus communication system that can be connected to your Lap Top. The entire system has data acquisition built in as well. For a race car that would be important. The extra touch-screens they offer for the Holley systems allow you to set up a custom gauge setup, the touch screens are expensive so I am happy using the 4" touchscreen that came with my Sniper System. Even on the hand held screen you can customize the way it displays the data YOU want to see. It has the ability to have a block turn Green for "okay", Yellow for "warning" and Red for a "problem" and you pick the various points yourself. It helped me out when my alternator decided not to make any power as it showed the voltage as green to start and turned to yellow as it dropped into the 11 volt range. It is a very well designed system that should make your race car even more fun.

The most important part was that my L88 Hood stay functional. The L88 Hood is the major difference and keeps my compression happy with ambient temperature combustion air, not the Hot engine area air that enters the combustion process already hot. The cooler the intake air the more power I can make. The cooler air also slows down the detonation and the faster you go the air pressure forces more air into the engine. This Hood was one of the Tricks brought out by Chevrolet in the early 1960's on their Mystery motor used in several race cars. I have read that this hood actually makes power for the Engine by forcing air into the intake from the base of the windshield.

Since you have been actively racing you might benefit from the Super Sniper Stealth as it has a bunch more features I wish I had. The basic sniper software is absolutely amazing all by itself. Have you downloaded a copy of the Sniper Software and looked at what you can do with these systems? Try it and you will be sold as the software lets you add Gauges on a single wire and even add a Nitrous system wet or dry. Since you have the 11.5-1 compression ratio you might benefit from the second fuel tank option offered in the Holley Software. With this software I can connect my Water/Methanol injection system as a 2nd fuel tank and control it with the vacuum signal. The one thing it does not have is a Knock sensor but I am working on a way to incorporate one into the new Holley system. I was actually thinking of installing a Edlebrock Pro Flow 4 system with a new intake manifold with injectors mounted on it and a throttle body on top. I decided I wanted my C3 to look like a C3 when you open the hood. With the drop base plate the throttle body is centered perfectly in the L88 Hood and nobody will be the wiser unless they see 60 psi versus 6 psi on my fuel pressure gauge. I am going to remove the glass faced gauge from the system after I am finished setting it all up. I really don't want 60 psi of gasoline spraying out over my engine so no glass gauges stay on my engines. If I need a fuel pressure gauge I will buy a sending unit and an electric gauge.

I am looking into the fire control systems. Fire is the one BIG thing that scares me with older Corvettes. I have protected all my fuel lines from heat and abrasion. I want a fire control system that is a bit better than my small Halon extinguisher I keep in each Corvette. When I first installed the Headers and Chambered exhaust on my C3 is when I bought the fire extinguisher to keep in the Corvette. My cousin told me about the Corvette Fires he had seen due to people trying to put headers too close to the fiberglass. I like being safe and having fun. But with gasoline at 58-60 psi and water/methanol at 150 psi in the same engine compartment I would really like to have some sort of automatic system. I don't know what the extinguishing gas of choice is today But I need to do something.

I survived my heart surgery and was told to take 14 days to recover. It feels much better to have that behind me. The doctors did the whole procedure through my Femoral Arteries and a couple BIG veins. They just don't want you to have a leak at the femoral artery as you have less than 90 seconds before bleeding out. I was Black and Blue for 2 weeks in my gut afterwards but they did not have to split my chest open...

I hope that you and your family are all doing well and staying away from the Covid virus! Take care and Good Luck with your Corvettes!

Best Regards,
Chris

 

Good morning Chris it’s always good to hear from you.
Yes I think the Holley Super Sniper stealth would be the go. I think Holley has purchased Racepac so all the Vnet CAN bus stuff is available, it’s the same a Haltech CAN bus V2 I think. Mind you I think that Vnet stuff is extremely over priced, here anyway. I’m not ready to upgrade the racing 84 just yet but it is a medium term plan. When I do I will contact you because I think after sales support is important especially with a non standard setups. My racing corvette has that huge Lunati cam that only comes on above 4000 and make max power around 7000 or so.

With regard to fire suppression my race car has a big dry power tank with four nozzles. Because it’s for a racing car the tank is just mounted on the floor in the passenger foot well, but in a C3 road car maybe you could put it in the luggage compartment behind the seats. There are two types an electrically activated version and a manual version. We installed the manual version which is activated by a pull handle near the rear vision mirror. We have one nozzle pointing at the carby, one pointing at the drivers harness buckle, and two at the fuel tank and fuel pump which is located behind the driver and protected by an aluminum firewall. Halon has been band in Australia for quite a long time now. All the data centers and computer rooms I work in these days have CO2 systems now (which will also kill you) but they won’t really work in a car so dry power is probably the go even though it’s messy.

I don’t think I knew you were going in for heart surgery but I’m glad you sound like you have pulled through ok. Try and stay healthy and keep away from the Covid. We are pretty lucky here with not many cases now, but it’s a trade off and things change quickly.

kind regards Greg

 

walker/dynomax super turbos practically the same thing, both are good.
Mufflers dont really restrict much unless youre making a bunch of power and have a lousy set on.
Talked to a Dynomax rep a few yrs ago and said they are slowly phasing those mufflers out so get them if you can. (ive had a set in the box 3 yrs and finally about to put them on).