Triumph Rat Motorcycle Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Bike of the Month Challenge!

1 - 20 of 34 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
I have an '06 Scrambler which I purchased used. It has the TOR mufflers and the air injection has been plugged off. It runs fine, so I assume it was re-jetted but can't verify. It has the stock air cleaner set-up.

I'm looking to max out the power using the parts already installed, but without going inside the engine. I'm figuring the only thing really left then is choosing the right air intake. Either I can replace the existing filter with a K&N and install one of those snorkles for the air box - or toss the air box all together and get small K&N filters for each carb. Cost-wise, the former is probably cheaper. I'd also have to think about which jets I should be using, depending on how I deal with the air intake.

Any thoughts out there as to the best approach? Have I missed anything that should also be done?
 

·
Moderator
Joined
·
30,527 Posts
Yes, removing the airbox and adding good pipes is certainly one method. And a good one, 'cos I did it. The poster did want to keep $$s down though, hence recommending the gutting of the airbox.
 

·
Premium Member
Joined
·
1,016 Posts
like prop mentioned, gut the stock airbox, and put on some emgo pipes and rejet.
 

·
Moderator
Joined
·
30,527 Posts
Yes they do. Not sure how good the emgo ones are in comparison - don't know if they fit the scrambler. You may as well stick with TORS - they are reasonable and you wont notice a whole lot if you spend the $$s and only gut the airbox a bit.
 

·
Registered
Joined
·
5,543 Posts
Randy,

Prop makes very excellent points. Check out the thread(s) on airbox mods, especially the total gut out, dual entry to the filter, and Velocity Stack installation portions.

"Bang for the Buck" - wise, arguably one of the the best mod you can do. The stacks are Mikuni's, part #'s, etc. are in the thread. You can get these in the US for about $12.00 each.

The TORS should be fine for a while. The difference in flow, unless you are building a drag bike or dyno racer, will not be an issue for a while, or until you perform major, major air flow mods through cylinder head flow work and camshaft changes. Realise that requirements for more air CFM are relative to RPM. That said, the difference in exhaust airflow during average street riding, i.e., < say zero to 6000 RPM, is not tremendously different from brand to brand, especially when you factor in $$ Spent / HP gained in that powerband. Usually the powerband with less and less restrictive pipes is just shifted upwards, or narrowed, so again, the difference in your case, and under your prescribed budget may not be worth the investment. The exhaust sound may be different of course, and that's a personal choice.

If you do the Airbox mods, check out the aforementioned Thread(s) carefully for jetting recommendations. IMHO, a good start point would be #140 mains if you do the total gut, dual entrance, Velocity Stack method. I've been up to #145's but the trade off between power gained and loss of MPG was not worth it, so I backed off to #142.5's.

Trust me, you'll love it, and you've only spent $24.00 for the two stacks, $54.00 for a K&N or Unifilter Intake Filter, and say $13.00 for jets. Obviously your labor charge is free.

Timewise, I would dedicate the better part of a long Saturday to do the mod's. If you have a Motorcycle Jack (Torin or Craftsman, about $70.00-excellent investment), jack the bike up slightly, disconnect the two shocks, remove the left side silencer mount, remove the seat, the battery, and the rear fender. Disconnect all the wiring harness's and misc. stuff from the airbox sides.

Now you can jack the bike waaaay up, and as the rear wheel/tire stays down, the rest of the bike rear goes way up, and the airbox slips out the back easily in one piece.

It sounds like a lot of work, but only takes about 15-20 minutes tops.

Again - before the usual flamers have a field day - this is a budget minded mod. If you have an excess of cash to spend, there are an endless, endless amount of mod's you can do, but the challenge was to improve things without "entering the engine".

There is also an intangible enjoyment from doing this type of work, as it takes a certain amount of craftmanship and ability to perform this style of handy-work, which returns a different type of satisfaction than say a "bolt-on" replacement type improvement. It's a lot of fun, and a good way to spend a Saturday..
 

·
Registered
Joined
·
1,687 Posts
I have an '06 Scrambler which I purchased used. It has the TOR mufflers and the air injection has been plugged off. It runs fine, so I assume it was re-jetted but can't verify. It has the stock air cleaner set-up.

I'm looking to max out the power .............
Any thoughts out there as to the best approach?
Well now!! Where do we begin!!

+1 on all the above comments.
You pays your money and you takes your choice, and almost all of the choices are detailed in the link which Prop has provided.

As has been said, cost-wise your best place to focus is on the airbox and the exhaust.
Everything you need to know, airbox-wise, is probably contained here....
http://www.triumphrat.net/1132928-post9.html

There has been much discussion and contention in which is the preferable direction to go but it has undoubtedly been proven now that the gains to be had by purely removing and/or gutting the airbox are closely comparable.
You will tho have to do a little more than "replacing the existing filter with a K&N and install one of those snorkles for the air box"

As Gob says, the entire gutting/opening/modding of the existing airbox can be carried out in less than a day at only minimal cost.
The alternative ARK'ing will take about the same, but the cost implication will be much greater.
The results tho will equate fairly closely.

So, the choice is yours.
The choices of many others have been well documented on this forum so all the info you will need to make a decision are contained here.

Enjoy the journey!!

V.
 

·
Registered
Joined
·
8,877 Posts
I think maybe you guys should look at the cost of cutting the air box and finding a deal on some pods .The cost is about the same if you buy the filters at the right price.What one needs to look at is what will I do later as far as mods go.Some had got good power with the air box in place with pure stock motors .But if later you want more hp after a point the stock air box will no longer cut it.I am in no way saying anything againest the guys that have done the great work on there air box and made good power with them ,but for every one of them that went that route there are 20 that made the same power with out the air box.Maybe its just me but why do all that testing to make the air box work its kinda like reinventing the wheel to me .
One thing that is fact the highest hp these bikes have made has been with no air box.
 

·
Moderator
Joined
·
30,527 Posts
I think your point about thinking ahead to future mods is well made Mike, but in this case the performance improvement doesn't cost anything - it's merely modifying what you have.

Should the OP gut his airbox, and then further down the road decide he wants to go with even more serious improvements, he can simply remove the airbox at that stage, and won't be out any cash on the deal, but today will save some $$s. It's different to (for example) buying a medium set of carbs, only to find out a bit later that you want big carbs and are therefore 600 dollars or so out on the deal.

It won't take much work to do, because people like Ventura have posted the "how to" details - it's a no brainer to me. Gut the box, pull it out enturely later on if you do more serious stuff.
 

·
Registered
Joined
·
8,877 Posts
I think your point about thinking ahead to future mods is well made Mike, but in this case the performance improvement doesn't cost anything - it's merely modifying what you have.

Should the OP gut his airbox, and then further down the road decide he wants to go with even more serious improvements, he can simply remove the airbox at that stage, and won't be out any cash on the deal, but today will save some $$s. It's different to (for example) buying a medium set of carbs, only to find out a bit later that you want big carbs and are therefore 600 dollars or so out on the deal.

It won't take much work to do, because people like Ventura have posted the "how to" details - it's a no brainer to me. Gut the box, pull it out enturely later on if you do more serious stuff.
That is true what i was talking about is buying stacks and a filter is about the same cost as some cheap pods and cutting the box out for them
 

·
Moderator
Joined
·
30,527 Posts
Yes that's fair enough - a matter of choice at that point.

Of course you can do what some others have done, which is cut away the airbox almost entirely and put the pods on. There are some good threads on that in my original link too, which is I believe what you are referring to.

That way you can use the bottom prtion of the airbox as a little storage area too, if you're into that sort of thing. Keef did that, and his thread is linked there.
 

·
Registered
Joined
·
1,394 Posts
Sounds like you want the most for the least ( or practically nothing ) .

If the Scrambler is going to be an on road sunny day bike you can do an airbox removal kit . But ant offroading I'd say keep the air box , buy a K&N or a Uni filter ( Uni filter's cheapest ) . Check your jetting . Simple . unscrew the bottom pieces ( the bowls ) on your carbs and you'll see the brass thingies ( the jets ) . One will hang lower . Unscrew it using a flathead. If it says 110 it's the mains ( the right ones you're looking for ) and get some bigger ones . 115 , 118, 120s or even 125s . Depends on the bike and where you are . Or simply take it to a shop and tell them to rejet your bike . Chances are your bike could of been purchased with the TORs and Triumph recommends that you can use stock jetting with TORs . You can but the bike runs a tad too lean . Best to up the main jets . 1 or 2 sizes .
A rejet would set you back at a shop 100-150$ at most I think . The bike will run 10X better too. Won't be chasing Busas or anything but it'll run better .
 

·
Registered
Joined
·
5,543 Posts
Maybe its just me but why do all that testing to make the air box work its kinda like reinventing the wheel to me .
One thing that is fact the highest hp these bikes have made has been with no air box.
Mike,

I'm extremely surprised to hear this type of statement, especially from a respected modder like yourself.

This from the guy who has at least replaced big bore kits, carbs, cams and exhausts all within the past 12 months?

"Re-inventing the wheel" is what development is all about. I'm sure back in the late 1800's someone thought that putting a motor on a bicycle was a pretty dumb idea too(LOL), but then look what happened!

In the end, it's how much high velocity air that can pass over and around the valve face,through the valve seat, and efficiently fill the empty cylinder chamber.

Putting less and less retrictive air filters on the bike is effective only up to a certain point, after that, it doesn't force more air in, as you know. I don't know of anyone in the past that opened up both side of the airbox to take advantage of dual filter inlets, then totally gutted out the airbox, then fitted velocity stacks. That said, it's not re-inventing the wheel, it's being innovative, creative and new. The total area of the intake openings - both sides - far exceed the openings of the carbs, and the box itself provides a chamber to prevent excessive turbulance, and that is an excellent and proven excellent provision. One could also argue that the additional length provided by the velocity stack lengthens the intake plenum and aids in the pulse reversion charge as well.

Many in the past have drilled holes in the airbox, but this as we know is not recommended - allowing unfiltered air in - and also the total area of the small holes doesn't equal the area of the carb inlet unless you drill a ton of holes, and then you have unfiltered air PLUS a lot of turbulance at the carb opening.

It would be interesting to place one of these highly developed airboxes on a flowbench to actually see how much air it can flow. Anyone have easy access to a flowbench? If the airflow then exceeds the CFM requirements of the motor, done.

I'm not certain anyone has tried one of these new airboxes as outlined above on an motor that has had extensive cylinder head work and a specially developed cam profile for high velocity airflow, so making the blanket statement that these would not work is counter to the spirit of this forum. It's "Twins Technical Talk", not "Twins Technical Listen", isn't it?

Let's all be a little more open minded and flexible, and support development and new ideas. I know you better than that Mike, so no offense meant, but it needed to be said. Let's not get so stuck in our ways, and automatically refute the efforts of other modders on the site.

Happy Mothers day!!
 

·
Moderator
Joined
·
30,527 Posts
That's all very interesting, I think Mike was just offering the option of cutting the airbox away and putting pods on as another similarly priced means of getting a similar performance improvement.
 

·
Premium Member
Joined
·
722 Posts
I have a question.....the Triumph manual does not mention that the rear wheel must be removed to get the box out. And indeed, another poster in this thread does not include that step either. I have read here that you have to do that to get it out.

It's insane to go through that hassel if it is not absolutely necessary IMO.

I read where a guy took one side of the box off and got it out as well. You can always put it back together with the screws after removal.

So there is a conflict here. What is the MINIMUM required removal of parts to get it out WITHOUT destroying it?

In the near future I am going to purchase either the NARK kit or the BC kit. Any recommendations as to which one is better?
 

·
Registered
Joined
·
8,877 Posts
air flows best in a stright line if the air comes in the side the air box it has to do a right angle turn.That may work fine with near stock heads and carbs.I have yet to see it work with the big carbs ,a high flowing head and big cams.Have you seen anyone make 90 hp or more with the air box ? I have seen some with pods do that.For that mater haveYou made 85 hp with one of our motors yet? I got a pretty good idea how to get these motors to run ,unless something makes more hp I dont play with it,no need to.If I had to run a air box to be legal where I live I would be testing stuff to ,but I dont and I know the right pods flow more air .Thats my 2 cents take it or leave it lol.
 
1 - 20 of 34 Posts
Top