Advice on GYTR quiet insert or Promote billet silent insert.

[Nixinus]

I'm new to the forum and a new owner of a 2007 WR450. The bike is street legal but cops around here notice loud bikes. I also would prefer if it were a bit quieter.

Bike has the stock exhaust with the pea shooter removed. All free mods done amd AIS removed. It's been jetted by the previous owner (spot on, maybe a bit lean on the top end). I want to quiet it down but not loose much power. I'm looking at getting a powercore 4.1 with quiet insert but I dont know if it will quiet things down and financially I would prefer an insert, for now.

What are your thoughts and experiences between the GYTR insert and the one from Promotobillet?

Thanks!

[FORMA MOTO]

The pipe you have is quieter than the Q4, and WAAAAY quieter than the Powercore....even with the quiet insert.

Both inserts are essentially the same.

[Nixinus]

I've read the insets might net you about 10 db, depending on what you start with. Any change to the jetting? Since I'm coming from a more open system I figure it will richen things up by restricting air. Would this affect the low end or the top end more?

[FORMA MOTO]

4 hours ago, Nixinus said:

I've read the insets might net you about 10 db, depending on what you start with. Any change to the jetting? Since I'm coming from a more open system I figure it will richen things up by restricting air. Would this affect the low end or the top end more?

You can't do it that way.

The intake flow and exahust flow need to be matched.

If you restrict air, it will just be slow and have terrible throttle response.

[Nixinus]

23 minutes ago, Krannie McKranface said:

You can't do it that way.

The intake flow and exahust flow need to be matched.

If you restrict air, it will just be slow and have terrible throttle response.

Ok, thanks for the info. 

Since the airbox is opened up (baffle out and holes drilled in the top) would putting either of the silencers on the stock exhaust restrict it enough to cause issues? Between the GYTR and Pro Moto, which would you think would be a better option?

Thanks again and sorry for my lack of knowledge on this subject. This is my first 4 stroke dirt bike. Everything is a learning experience.

[FORMA MOTO]

10 minutes ago, Nixinus said:

Ok, thanks for the info. 

Since the airbox is opened up (baffle out and holes drilled in the top) would putting either of the silencers on the stock exhaust restrict it enough to cause issues? Between the GYTR and Pro Moto, which would you think would be a better option?

Thanks again and sorry for my lack of knowledge on this subject. This is my first 4 stroke dirt bike. Everything is a learning experience.

The stock exhaust is not straight through even with a new end. Both ends are about the same.

The opened airbox is fine

You want jetting of  160main, 45pilot, NCVS or JD Red needle on 3rd clip, stock everything else.

Service the apump with the new upgrades

Service the hotstart for corrosion, and put on a alloy cable cap, as the plastic one is probably shot already

If you go to a straight through exhaust, you can go up to a 165 main