33 replies to this topic

[Dave Lewis]

Mazdacomp exhaust will fail w/1.6 and pass w/1.8, or the other way round. I forget. I'm old, ask Ralph or Dutch.

[RazerX]

Does anyone know what dB the MBS does run at our pass?  90?  92?  97?  I'll shoot over an email to MBS as well. 

 

BTW, NA mazdacomp was very quite I had one for Laguna and never had an issue. 

[38bfast]

The MBS is more quite than the Mazdacomp

[RazerX]

That seems amazing.  HP / TQ as good as an SD and the sound quieter than Mazdacomp.  Guess I am ordering...

[Jerry Cabe]

Thanks for all the input; I may contact one of you in the near future to discuss in more detail once I decide which way to go.

[Sphinx]

One unanswered question in this thread is whether an MBS exhaust meets MRLS's 90db limit - anyone?

[Sean - MiataCage]

We have dyno'd the MBS on multiple 1.6L cars and multiple occasions and it was not good.  Someone talked me into this thing saying it was the cats PJ's.  It sucked, all numbers went down.... I'm pretty sure It ended up on a chump car.  The piece is nicely built, but it didn't make the power.

 

I like Ralph and I don't discount what he is saying, I am just saying we saw something completely different.

 

If you are going with one of these exhaust systems I encourage you to dyno before and after the installation.  You can do it at the dyno and it will tell you for certain if it helped or not.  For Laguna we just bolt on an additional muffler in the old stock location like Saul said back on page 1.

 

Buyer beware......

[38bfast]

The top power generating cars on my dyno had the MBS exhaust on them. We have puled cars with may different exhaust on them and across the averages the MBS works the best for us. I have no skin in the game with MBS but they work for me. Dan had Kooks make a very similar exhaust for him and he has seen gains with his as well. 

 

Sean I am not sure why you are not seeing the gains we are. I do have to change the tune from one exhaust to another. 

[Sean - MiataCage]

Thanks Ralph... I never thought about changing the tune..... That must be it.

[Jim Drago]

My results agree with yours Sean..

I have never put an MBS on that worked as well, let alone better than an SD exhaust.. The MBS fits much better, looks better.. but does not perform as well. I have tested countless times in every way imaginable with a-b-b-a testing. We wasted two full days on the dyno a few years ago testing exhausts, plus, oils and several other things.. We wasted two days

Jim

[mhiggins10]

My results agree with yours Sean..

I have never put an MBS on that worked as well, let alone better than an SD exhaust.. The MBS fits much better, looks better.. but does not perform as well. I have tested countless times in every way imaginable with a-b-b-a testing. We wasted two full days on the dyno a few years ago testing exhausts, plus, oils and several other things.. We wasted two days

Jim

It's not necessarily a waste- at least now you know where to put the money in a build.

 

(And so do we- at least on the plugs and oils.  Thanks for sharing!)

[Sphinx]

My results agree with yours Sean..

I have never put an MBS on that worked as well, let alone better than an SD exhaust.. The MBS fits much better, looks better.. but does not perform as well. I have tested countless times in every way imaginable with a-b-b-a testing. We wasted two full days on the dyno a few years ago testing exhausts, plus, oils and several other things.. We wasted two days

Jim

 

Thanks for clarifying, Jim.  Post #16 indicated that you had found no difference, but I'm glad you chimed in.

 

On the suggestion of a couple of local guys, I'm getting a muffler attachment for my SD that will work at MRLS.  TC Design is the local race/fab shop.

[Sphinx]

Today's question:  So, I can't get a MRLS exhaust fabbed up in time.  If I short-shifted all around the track, could I keep it under the 90 db?  Say 6000rpm, instead of 7000? (this is for a track day).

[Bench Racer]

Have you tried an elbow and turned it the opposite way of sound mic?