The Zilla in question is an 89, stock head, stock Wiseco piston and mild overall porting, , 41.5 carb, Boyseen Carbon fiber reeds and running on a mix of 93 and 100 octane. Humid as hell and about 85 degrees. The first run is with the out-frame FTZ drag pipe, the second is with an LRD set up in the top-end setting. Bearing in mind that the FTZ is suppose to produce far more top end power than the LRD, which is an in-frame design, Numerous runs were made with each pipe, this paticular one held the greatest margin of difference at 9hp. This was an all gear run. 4th gear roll-ons also produced higer gains for the LRD in the neighborhood of 6hp. Also, the LRD made more low-end power and torque than the FTZ. Gaining 9hp on an aftermarket pipe over a stock one is a great improvement, but gaining 9hp over a aftermarket drag pipe is unreal. The runs were made at High-Lifter in Shreveport La, great guys by the way,very friendly, helpful and knowledgable. I have stressed the LRD pipe before, but this time I have something to back up my seat-of-the-pants feelings. If I have left any info out, please ask.

http://www.ls1camaro.net/freehosting/FTZvsLRD.jpg

The blue line is the FTZ and the red is the LRD

 

I am sure that an FTZ drag pipe is designed for a built to the max drag engine. Mild porting and mild compression doesn't mix well with a huge pipe....... Using a pipe that is too large for your engine set up will equal a loss of power.

Also, did you change the jetting for the larger pipe?

 

Your dyno chart

One more thing, what's the deal with the ups and downs all the way across your dyno run?

 

It was an all gear run, meaning what the engine was allowed to rev out in each gear, 5 peaks, 5 gears, the downs are when the bike was shifted, shifting too fast on a dyno will result in "clutch spikes" and will not allow for accurate testing. It was understood that the FTZ would shine as heavier engine mods were added, but it would still be a feat for the FTZ to pick up 9hp and equal the LRD even with this considered.

 

Also, an A/F ratio was taken throughout all runs, and the ratio never moved more than .3 points between the 2 pipes. Both were just a hair rich and WOT, but nothing to cause a mesuarable loss in power.

 

The FTZ and LRD pipes are totally different designs.

Where are you measuring the A/F ratio?

Also, did they give you a dyno sheet that shows RPM's. If so, please post that as well.

I would bet that FTZ testing was done with their all out race ported engine package. At a minimum, I would bet they are running around 230 pounds of cranking pressure with 108 or 110 race gas.

Don't get me wrong. I'm not knocking the LRD pipe at all. I just think you're waisting your time with a huge drag pipe on a mild mod engine that doesn't even require race gas. A big pipe needs big porting, and it especially needs high compression.

 

the AF was measured with a sniffer inside the tailpipe,If you look to the left of the dyno sheet where it says "Power HP" that will also double as the RPMs, 30=3000RPMs, sorry I left that out. Peak power was around 6000 give or take. I completly understand where you are comming from, and I also feel quite sure that with about 200+ of cylinder pressure and a drag port job the FTZ would wake up considerably. We have dynoed the LRD against the Trinity, CT, PT with the LRD always comming out on top by a considerable margin. We were just curious if there was anything to be gained by going to an all out drag pipe since the LRD is more of a top end orented pipe and it was beating the hell out of everything else.

 

Good info....very interesting. Check out the graph and power compared too gearing. The engine is making the same power, but the gearing alters real world power. It's making more power with more gear....this is why gearing up can make a quad quicker.....IF, you have the power too pull the additional gearing. Makes me wanna get my extra gears back out...[img]i/expressions/face-icon-small-smile.gif[/img].

 

Is it common to use an A/F ratio measurement at the tail pipe on a 2 stroke?

Peak power at 6,000 rpm's....... That seems really low, doesn't it?

I assume you will eventually go all out on the engine. Keep us posted on how it turns out.

 

Yeah, Quadzillas are a relatively low RPM engine, especially for a 2-stroke, If you have ever ridden one you would feel that they rap out very quickly, especially if you dont have a pipe that caters to higher RPMs, I used to get off my Banshee and get on my 500 and find myself running it to high, just because I was used to the Shees higer RPM capabilities. As far as the AF ratios go, unless you tapped the pipe and ran a wide-band O2 sensor into it like you do on a car, a tailpipe sniffer is usually the tool of choice for measuring AF ratios.