Triumphrat

Ventura · 02-13-2009, 09:29 AM

Some time ago, after completing various airbox mods (without removing it) I fitted a 790 Inlet cam to my '06 865 Scrambler.

The post from that time is here:

http://www.triumphrat.net/1154426-post1.html

I've since had it on the dyno, which has produced the following results.
To serve as a comparison I've overlayed the stock unmodified Scrambler traces which I plagiarised from the T'Bike website.
(I assume its accurate!)

I'm very happy with the results which more or less backs-up what the SOTP was indicating.
The max hp figure is now up to that of a de-airboxed Thruxton and I've managed to retrieve most of the lost low-down torque by having Pieman work his magic on the igniter, both in remapping the ignition advance and increasing the rev limit.
The difference between the stock figures and now are pretty good, and when considered against how relatively little I've had to spend to achieve this, the bangs/buck value is extremely good!!

One thing I'm very happy with is the almost flat AFR trace.
Just goes to show how useful a tool the A/F gauge is, as I couldnt have achieved this without it.
I'm told that the richening at the top end of the revs is to be expected. Im assuming the low-end readings are an incorrect indication and must be a product of whacking the throttle open for the power run. The readings were actually flat from tickover to 8500rpm.

Another point of note is that the two traces are showing the difference a Thruxton needle makes against the standard Scram needle, this being the only change I made between runs.
More power, more torque, and across-the-board effect on the A/F ratio.

Most of my mods were in gutting the airbox to almost as far as is possible without removing it (so no ARK to purchase), fitting the cam and purchasing the Zard exhaust. Everything else is as per my signature below.

I realise that it will probably be pointed out to me that I could flatten out the top of the power curve (or even increase it) by removing the airbox and fitting pods, but really I've no inclination to do so bearing in mind what I've achieved thus far, and by the means I've achieved it.

I look forward to hearing the comments of those who are more conversant with dyno run results (this being my first!) and most of all I cant wait for Mike's valuable input!!

V.

propforward · 02-13-2009, 10:11 AM

That is very well done indeed Ventura! Cooo - ell!

That certainly verifies the effectiveness of that a/f guage - I am even more pleased I bought one now!

fullplat1 · 02-13-2009, 10:22 AM

Hi There
nice job!!!!!! I guess you could do the cut-away air box and fit pod filters, would only cost you the filters

Anyhow.... what A/F guage did you use and was it sourced in the UK????
Phil

beemerrich · 02-13-2009, 10:38 AM

Very nice improvement. You're exactly where I'm at with my thruxton w/ nark & d&ds...though your torque curve carries 50 ft-lbs+ later than mine (I peak at 3500) and has an earlier/wider peak HP band.

You must be pleased as punch with that fat, 60 hp+ powerband spanning from 6200 through 7800...undoubtably a joy to ride.

Ventura · 02-13-2009, 11:00 AM

Quote:

Originally Posted by fullplat1

.... what A/F guage did you use and was it sourced in the UK????

Phil,
I bought the A/F kit from Burton Power here in UK

http://www.burtonpower.com

The details of the install, including costs, are here:-

http://www.triumphrat.net/twins-tech...e-install.html

Quote:

Originally Posted by beemerrich

...undoubtably a joy to ride

Certainly is B'rich. A transformation of the bike I bought 8 months ago!!

V.

sweatmachine · 02-13-2009, 02:30 PM

Quote:

Originally Posted by Ventura

I realise that it will probably be pointed out to me that I could flatten out the top of the power curve (or even increase it) by removing the airbox and fitting pods, but really I've no inclination to do so bearing in mind what I've achieved thus far, and by the means I've achieved it.

You're right, and fitting bigger carbs (a la FCRs or Mikunis) will get more of everything everywhere, esp on top.

congrats! I'm sure it is a lot more fun to ride than stock!

MONTTU · 02-14-2009, 07:18 AM

Interesting,

Almost identical result as mine. It seems that having 790 ex cam too like I have does not make much difference.

B02S4 · 02-14-2009, 09:54 AM

Good show; keep in mind this is a DIN correction factor when comparing numbers.

mikeinva · 02-14-2009, 01:21 PM

Quote:

Originally Posted by B02S4

Good show; keep in mind this is a DIN correction factor when comparing numbers.

Yea but thats still over 58hp sae.Not bad for a stock scram with a air box.Bet theres a few more hp there waiting to come out if it could get some more air.Even more with some real good cams,If i am not mistaken even those 270 cams still fall short of the 360 790 cams .Those sould be close to 865 360 cams but I am not sure.Anyone know how they compare?
I can tell everyone this I have said how do we know the after market cams are any better cams then the old 01 790 cams.Well I have a set of 813 tpusa cams now and I can say they are more cam then the 01 790 cams.More lift ,more duration, but not enough to make them afect the ride abilty of our bikes.This is a good thing because if you buy 790 cams now you get the 02 and later cams .

Ventura · 02-15-2009, 11:26 AM

Whichever are the strongest cams, I think the results here show just how much can be gained from basically installing an off-the-shelf. relatively inexpensive alternative to stock, which only takes about an hour to fit.

A definite Hp/(Buck, Pound, Euro)/Hr bargain!!

And the efforts and advice of the likes of MONTTU, Mike, JohnyC and Pieman are certainly appreciated in pointing the way.

V.