Triumphrat

FrankBlack · 03-18-2008

After much thought, I'm about to take out my airbox and install K & N pods this week. But just so's I know what I'm in for, I'd like to hear from those who've done this mod and what the pros and cons are that you've found (I've done lots of searches and haven't come across anyone expressing any 'cons' yet!). For example, how your fuel consumption compares before and after changing to pod filters; what your dyno readings were if you had that done; how well your bike runs throughout the rev range; whether you've any regrets about doing it. It may also be useful for others if you were to list your jetting and exhaust setup.

All the best.

pabonne · 03-18-2008

Do some searching and you'll find a ton of info on this. When I KARK'd mine I lost about 5 mpg but felt like I got at least 5 extra horses (butt dyno). Plus the sucking sound at WOT can't be beat.

As a daily driver, one thing I was concerned about was riding in the rain, but I've been caught in downpours with nary a hiccup.

Loxpump · 03-18-2008

I did the air box cut up, with K&N cones, and have never regretted it. Not sure if I lost any MPG's but I get about 50 mpg now so I'm not complaining. I think there was a noticeable seat of the pants boost, it sure seems to wake the twin up, and like Pabonne said the air induction sound is incredible. I'd say go to the dark side.

MudTub · 03-19-2008

Have done all these mods, and put 250 miles on bike the last week since mods finished, no regrets (or cons) other then my local dealer had a bit of a fit at my removing the airbox, didn't want to touch my carbs at first, but I think after they saw (and felt, put 10 miles on 'testing') the difference, he'll be doing it on his bike!.

Definetly makes the motor purr (maybe a small growl

), throttle response much better, engine braking not as nasty.

Did air box elimination, air injection elimination, new Dominator 'Sport' model silencers, 145 main jets, 42 pilots.

Taking it down to a local race shop next week to have dyno tuned, will post the after results, sorry, did not do a before.

RedBird · 03-19-2008

Frank,

A little advice...be careful comparing jetting, etc. between the 790 engine and the 865 engine. I believe both benefit from the airbox removal modification; however, the 790 may benefit a little more because of the different cams and cam timing.

I noticed no difference in before and after mpg on my 790....I still get 50+ mpg after 22,000 miles. I would recommend highly that you check your jetting on the dyno. IMHO, these carbs can vary greatly on jetting required. Mine dynoed at 67.5 RWHP at 7800 rpm. Max torque was 54.3 at 3600 rpm. Throttle response is very good throughout the rpm range, IMHO, for my 790.

I have no regrets after 18000 miles with the NARC. I haven't touched the carbs in 18000 miles, either. It starts better, idles better, runs better, has more hp, and I get the same mpg....I'm a happy camper!

FrankBlack · 03-20-2008

Thanks Larry, Fred, Mud. That's encouraging. I'm aware of the jetting anomalies from carb to carb, and the apparent differences in main jet requirements between 790 and 865 engines. I guess I haven't heard anything said against replacing the airbox and I suppose I'm a little of wary of win-win 'phenomena' (being a cynical Scot).

But it is encouraging to know that your fuel consumption hasn't dropped (much, if any). This seems to be the only 'con' I've heard so far (oh, and some loss of mid-range response for some people), and even then opinion varies. Indeed, some have reported better fuel consumption and mid-range gain, which is interesting, if not a wee bit confounding.

Anyone anything to say about their airbox removal on 865 engines?

Thanks guys.

Mattrat · 03-20-2008

Make sure you remember to install the carb brace

FrankBlack · 03-20-2008

Thanks Matt - I got this one:

raproe · 03-20-2008

I have a newly installed NARK. Because it is still winter here I have only been able to run it for about a day...but, like others have said...its a whole new bike. It really makes it want to run.

I strongly recommend following the Jenks Bolts guide ( http://jenksbolts.com/product_info.p...de8522bb4901af ) for the rejetting. I have an 865 T100 with Togas. Following Jenks, I put in 140 main jets, put one shim on the needle, kept the 40 pilots and turned them out to 3 turns (Jenks also recommends drilling the slide; I didn't do that yet). Since I hadn't run the bike in about 2 weeks, I feared it would be a nightmare to even start. Instead, it fired right up and felt like it just wanted to rev. I took it out for about 10 miles, brought it back to the garage, balanced the carbs and then took it out to see what it would do.

I had the Togas and the NH Bellmouth before I put the NARK in. With that setup, the T100 pulled real strong from about 2500 RPM to redline. I was afraid the NARK would reduce that low and mid range pull in exchange for a boost at the upper end. Not so. The engine now feels like an electric motor and pulls strongly through the whole range.

I'm looking forward to better riding weather so I can see what the mileage changes might be and see how it pulls through some of my favorite twisties. My only concerns are getting more tickets and wearing out the back tire sooner.

Rich

gaptooth grin · 03-20-2008

yes,well i went that route last winter and although i havent really had the opertunity to make an in-depth evaluation, after going around the block a few times ,,i can`t say that i noticed all that great of a difference/improvement over the previous set up ,,of uni. polaris,sans restrictor,and 128`s but i did notice a considerable increase of sound eminating from the intake area, but to be honest, i was so cold that i just couldnt really tell, but in the coming weeks, i plan on wringing that puppy out!
then i`ll either be bitching or bragging