GTM E4 V85TT Exhaust NOW WITH DYNO RUN

[GTM®]

Dyno graph below showing 80(!) rwhp with our GTM TT Werks Full system with the long Meg, DIY open air box with high-flow filter and RB EVO Fuel Kit w/GTM SAS Kit.

Proto Full System with Short Meg:


GTM Stepped Header system eliminates the silly covers. Skid plate stays:


Short Meg:

Long Meg:

Axis Dyno Full Kit 80 rwhp! GTM Full Werks Exhaust Long muffler (above), GTM RB EVO Kit, GTM SAS Kit with DIY open air box lid and high-flow filter (all available linked above):


DIY open airbox lid with high-flow filter element:

 

[Faisal]

Interest from those who have or will be getting a V85TT?

That looks nice. The finished product will look absolutely bitchin no doubt. Can't wait to see and hear the longer one with a cat delete.

Are you thinking of diversifying the design or will it just be one exhaust type?

How much gains in horsepower and torque do you except to see with a full exhaust system and a PCV?

 

[GTM®]

That looks nice. The finished product will look absolutely bitchin no doubt. Can't wait to see and hear the longer one with a cat delete.
Are you thinking of diversifying the design or will it just be one exhaust type?
How much gains in horsepower and torque do you except to see with a full exhaust system and a PCV?

Thanks, and diversifying how so? For the small few that will buy mine, I really can't spread my resources too thin. Everyone will likely forego mine for a bigger name brand, despite lesser quality and no dyno info.
Power gains: Based on my two decades of Guzzi dyno work, getting them to the crank rated power is pretty easy, so 80 rwhp. We shall see just how stifled this motor is here soon. Dyno info to come when done and the fueling kit sorted, which will take some time, as no one seems to have full access to the ECU yet.

 

[Faisal]

Thanks, and diversifying how so? For the small few that will buy mine, I really can't spread my resources too thin. Everyone will likely forego mine for a bigger name brand, despite lesser quality and no dyno info.
Power gains: Based on my two decades of Guzzi dyno work, getting them to the crank rated power is pretty easy, so 80 rwhp. We shall see just how stifled this motor is here soon. Dyno info to come when done and the fueling kit sorted, which will take some time, as no one seems to have full access to the ECU yet.

Have you seen the "big brands" you mentioned? Except for maybe one, they all look pretty horrible... That's a subjective matter, I understand, however; you need to actually be blind in one eye and have 90% cataract in the other eye to like the big brand designs over the GT-Rx design, even in its unfinished prototype phase.

I'll be waiting for the dyno results and the full exhaust system then. 80rwhp sounds nice.

 

[kiwi dave]

Is the new pipe going to allow a normal pannier on the LHS, rather than having to extend outwards to avoid the existing silencer?

I'd like to see a photo of the rear from directly behind.

 

[GTM®]

Have you seen the "big brands" you mentioned? Except for maybe one, they all look pretty horrible... That's a subjective matter, I understand, however; you need to actually be blind in one eye and have 90% cataract in the other eye to like the big brand designs over the GT-Rx design, even in its unfinished prototype phase.
I'll be waiting for the dyno results and the full exhaust system then. 80rwhp sounds nice.

I sure have! And to me, they are all painfully bad recycles.
Yes, I'm anxious to dig in. The ECU is in fact the same type as the California 1400 - with ride-by-wire of course.

 

[GTM®]

Is the new pipe going to allow a normal pannier on the LHS, rather than having to extend outwards to avoid the existing silencer?
I'd like to see a photo of the rear from directly behind.

Dave, I’ll snap one tomorrow. The stock muffler bolts to the outside of the mount, mine bolts to the inside as you see. I’m pretty sure mine is significantly inward. I also didn’t need to crush the connector pipe down like they did stock. My goal was to allow a symmetrically balanced bag set, yes.

 

[Faisal]

Todd,

Is there anything reasonable that can be done to the stock exhaust or cat that will cause a decent / adequate exhaust tone? Or is it too much of a hassle?

Something temporary until you're done with the exhaust system options.

 

[GTM®]

Is there anything reasonable that can be done to the stock exhaust or cat that will cause a decent / adequate exhaust tone? Or is it too much of a hassle?
Something temporary until you're done with the exhaust system options.

Nothing simple or easy, no. I guess I would start with just the Y-pipe, which is available now on the STORE link above.

 

[Faisal]

Nothing simple or easy, no. I guess I would start with just the Y-pipe, which is available now/soon. I should have one of mine ready to ship late next week.

I'll have to wait then. Shipping costs of several parts individually will probably cost as much as a muffler.

Also, removable baffle?

 

[GTM®]

I would like to see and hear the full exhaust (headers + y pipe + long muffler for bags). Will it have a removable baffle?

I'll can't show the long version until one is ordered. We dyno develop the muffler and db, so it would not be removable, however all of my systems have a nice deep sound and deliver great power.

 

[Faisal]

Full system prototype pic below. All pieces are modular and can fit the stock parts, including headers... however, the GTM headers and Y-pipe for the full system are larger diameter, so those would need to be ordered as a set. Muffler will fit stock or GTM Y. I’ll put the order page up in the next day or so. Based on the poll, looks like little interest right now, so they will be built to paid order only.

View attachment 17680

I see the skid plate for the headers are not installed. Is that just for photographic reasons or will they not fit due to the larger diameter?

Have you had any luck with the tuning process? I would like to place an order for the full system + long muffler but I'm waiting on tuning updates as well.

Thank you Todd. Great looking exhaust btw.

 

[Mayakovski]

Lookin' Sexy as Hell.

 

[GTM®]

I see the skid plate for the headers are not installed. Is that just for photographic reasons or will they not fit due to the larger diameter?
Have you had any luck with the tuning process? I would like to place an order for the full system + long muffler but I'm waiting on tuning updates as well.
Thank you Todd. Great looking exhaust btw.

Skid plate is still on. The silly header covers where they drop down to the tiny 1.5"/38mm diameter would not be reused, as those are just cosmetic covers.

 

[Faisal]

Skid plate is still on. The silly header covers where they drop down to the tiny 1.5"/38mm diameter would not be reused, as those are just cosmetic covers.
Tuning will take some time as they changed the Diag plug along with a new ECU for this bike. I will only sell the full system once I have the fueling resolved. For now, I will sell the Y-pipe and muffler.
Welcome otherwise. I'll update this thread as we go.

Alright, sounds good then.

I'll purchase the Y-pipe and muffler or possibly just the muffler until the tuning is done.

Just some clarification, please. You mentioned that the Y pipe and headers will be sold as a set since they are of larger diameter. Does that mean your Y pipe will not fit the stock headers?

Will Y-pipe + muffler combo cause deterimental leaning issues or would the bike be fine?

 

[GTM®]

Just some clarification, please. You mentioned that the Y pipe and headers will be sold as a set since they are of larger diameter. Does that mean your Y pipe will not fit the stock headers?

I will offer two versions for the Y:
1. One to fit stock headers and stock or aftermarket mufflers, or;
2. A larger diameter inlet on the one only used with my full header system.

Will Y-pipe + muffler combo cause deterimental leaning issues or would the bike be fine?

Several companies are offering the combo right now, but they have quite restrictive mufflers. Since I haven't yet seen any air/fuel data, I will say that it likely leans the motor out even more, which I say is detrimental until the fueling is fixed. That won't stop anyone else from buying the big name versions though of course.

 

[GTM®]

Stock bash plate with my prototype stepped header system, without the silly cover hiding the ugly/puny sized section of stock headers.

 

[Faisal]

Stock bash plate with my prototype stepped header system, without the silly cover hiding the ugly/puny sized section of stock headers.

View attachment 17687

I actually like the cover. I mean I don't hate it, it looks fine to me but to each his own.

Waiting on your sound clips! Can't wait to hear her burble with a proper exhaust.

 

[GTM®]

Will post a video tomorrow, but for now a pic of our first production muffler...

 

[Faisal]

Will post a video tomorrow, but for now a pic of our first production muffler...

Looks awesome.

How much longer is the long version going to be compared to the short version?