IT-7 MUFFLERS

[Dick Elliott]

What kind or type of muffler is everyone useing on their IT-7 race car? Any one try a spiral type muffler, like Moroso sells? Thanks, DICK.

[theenico]

When I was still working at a race shop, we used the Magnaflow 3" in/out round mufflers. Once the packing eventually burns out, we would then cut a 4"x6" hole out of the side of it, fill the muffler with lava rocks (for a BBQ grill), and then rivet a panel back over the hole. It's basically a cheap alternative to Mazda-comps Lava Rock muffler.

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Nico Prelogar

[Dick Elliott]

Which Magnaflow muffler? The stainless 6" Race muffler only comes in 3 1/2" or bigger sizes. The street muffler is 5" in dia and does come in a 3" model. Wouldn't the oval model give more room for the rocks, after the packing blows out? Thanks, DICK.

[This message has been edited by Dick Elliott (edited July 17, 2005).]

[theenico]

The 5" round fits in the car better. If you have a fuel cell, or a triangulated panhard mount, the oval one is a mother to get in there.

Forgot to add: You need to smash the rocks with a hammer until they are between 1 & 2 inches in diameter.

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Nico Prelogar

[This message has been edited by theenico (edited July 20, 2005).]

[ScottNutter]

I don't use a muffler. I'm probably not the fastest but the last 3-4 years I've been running a RB dual header and mid section(with prescilinesers) and straight pipes under the axle to the rear of the car. I've hit 100db but usually around 97-98db.

For what it's worth

[Dick Elliott]

Back in 85, I had a very simular set up on both my IT-A and GT-2 RX-7s. Only difference was the pre-silencers were at the back bumper. Worked great. Any muffler will be quiet'r at the end of the system.

[benracin]

What's the reason for putting the lava rock in? I'm putting an old Ultra flow back on my car and I'm wondering if this is something I should consider cause I'm not sure if there's any material in it or not. And are we talking about the rocks that actually look like lava rock, or are we talking about the fake charcol that you put in a gas grill?

[MaxEnergy]

Either ones work but I like using the used ones from the grill they smell great and when competitors get too close they get hungry and lose their concentration :-)

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Jamie Kekeisen
86 ITS RX-7 NER
92 325IS under construction

[Dick Elliott]

IS THAT LEGAL? Why not use cow patties so people will stay way behind you.

[This message has been edited by Dick Elliott (edited July 23, 2005).]

[mustanghammer]

What kind or type of muffler is everyone useing on their IT-7 race car? Any one try a spiral type muffler, like Moroso sells? Thanks, DICK.

Dick,

I have been experimenting with a LOBAK augger style muffler that is 3"ID X 19" long. I have been using a Dyno Max 2.5" ID bullet muffler filled with lava rocks that Nico built for my car. Both mufflers easily meet sound and the LOBAK sounds kick ass. However, owner (that would be me) induced carb troubles limited my findings on the LOBAK at HPT last weekend. I hope the the LOBAK works because it is lighter that the lava rock muffler and will last a long time.



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Scott Peterson
KC Region
IT7 #17

[Dick Elliott]

When I last talked to the Lobak people in Ca, they told me the cars at the Skip Barber school were useing a stainless Lobak on all their cars. I've used them for the past 30 years on piston engines, but never on a rotary. Have you put enough miles on one to see if they will last? One thing about them: no packing to blow out. Thanks for your info. DICK.