I currently have:
HMF pipe (usually run it wide open)
KN in the box w/ lid on
60% rwr springs
Back to stock cdi box and staying that way (unless I find a used vortex)
Mr.HP ported intake

I am also working on getting a TM45 (currently running the stock 42)

I know todays cams can give you power throughout the powerband for the most part which is what im looking for. I do all kinds of riding, everything from super tight technical low throttle woods riding to WOT dunes riding, so I would rather not have most of my power concentrated low or high.

All of my riding buddies own yfz's and with the weight difference its hard for me to stay ahead (I am 25-75 lbs more than them, plus the nearly 200 lbs difference in quad weight).

I am only 19 working a 7/hr job, so money is a bit on the tight side, so I need bang for the buck. I would assume there is more power with cams/piston which should be similar to the price of MR.Hp's trail/TT porting which is 600. One of my buddies with stock bore and only an HMF sent his head to a guy on ebay (risky I thought) and got it ported for like 180 (assuming he obviously isnt spending much time porting, and I was very surprised of the gains he got (about two bike lengths).

I do not want to run race gas, and some of the places we ride only 91 octane is available (93 is available locally, so only would have to run 91 on long trips when I run out of 93). What is the highest compression that can safely be run on 91-93? I would like to stick with whatever best suits my application, but I do like Mr.Hp's work and products.

What type of gains are had with the different available HPR cams? (is it just the hpr3 and hpr4 ive read about, or are there more?) I know there are also the woods cams which seems like a lot of people still reccomend the a1/a2 combo (I think thats right) what kind of powerband do those concentrate on?

If you guys cant tell I am lacking knowledge on this stuff, so any input and help is appreciated! I am about even with two of my yfz buddies and a few lengths behind on the others so I really want to be able to lead the pack again.

My other question is about what seems to me (again, not much experience except from reading about it) to be blow-by on my ds. For some reason ever since I did my gauge installs (oil pressure/coolant temp) I seem to have a lot of crank case pressure which is DUMPING oil out my vent hose. It got so bad on our dunes trip I had to tape 4 plastic bags around the breather just to catch all the oil. Now that we are back it is still dumping just as badly, and I dont know what it could be. I would estimate I am losing approximately a two tablespoons per hour of riding, enough that over a few hour riding period it is slightly noticeable in the resevoir level. I am pretty sure it must have somthing to do with the oil pressure gauge I installed, but I dont see how this is possible. It must be the gauges though because I did not do anything else to my ds recently besides the oil press and coolant temp installs. Am I experiencing blow-by? I understand what blow-by is on paper, and it would seem to me if there is a slight loss in the sealing, that there would be a pretty significant power loss? The quad seems to run just as well as usual with no odd characteristics so I am pretty confused. I just wanted to toss this in here so if somebody had a "DUH, you just need to do this" type of thing, I wouldnt have to worry about it still doing it after my new parts get installed.


Again, any help is greatly appreciated!
Mike

 

I cant really give an acurate account to which upgrade would sute you best. I had the same problems my buddies all weigh about 180 or so and im at 305. these guys were running off and leaving me. I did the whole mr.hp build at one time so i cant tell you which one gave the biggest power gain. From what i understand cams are a pretty nice upgrade. Since you do tight trail riding i would not recomend the hr4 cams these are super agressive. I told him i wanted a fast bike and boy did he come through. If you have the ported intake already and a pipe i would get the camsbut not to agressive. When i took the lid and snorkals off my bike i felt some difference in the power. Air is power more air more gas more power. Get away from the stock carb. good luck

 

Get the carb on. Its going to broaden your torque everywhere.

 

Roost,

I would recommend a TM45 to go with your ported intake. The Ron Wood A1/A2 Cams have a lot of low and and still do well on the top. If you dont want to run race fuel, you will not want a higher compression piston. Then I would put a nitrous system with a 15 shot. Its possible to go up to 20 with the stock piston. I like the Boondocker system because its pretty safe. You dont have to keep checking your bottle pressure to make sure you wont be too lean - and once it set up, its very hard to mess up. The A1/A2 cams work well with Nitrous. Plus, when you run Nitrous, you'll bring your power curve down another 1000 rpm - which will give you more power everywhere, including the low end. I'd recommend that you run a step up in pump gas - not regular, but plus.

The Nitrous is about 5 dollars a pound here. Just push the button when you need it for an extra 15 horsepower. You wont be able to go more than a 20 shot on the stock piston. The Boondocker is pretty easy to install. The hardest part is finding a regulated power source, and even that isnt that hard with a volt meter. The ones that I have put on take about 3-4 hours - but I'm pretty meticulous.

Keep in mind you wouldnt have to change out your carb to a TM45 if your decide to run nitrous. But it will help a lot when you arent running nitrous. The cams work well with or without nitrous and of course so does the carb.

This is probably the least expensive way to get the most power without causing any problems. That system would be very user friendly and would be very easy to maintain.

 

I think I worded everything badly, but the carb (tm) will be going on for sure, and I want to know what would be best, cams AND piston combo, or just porting alone (90% sure cams/piston are the way to go)

I just dont know what each cam profile delivers power wise on the ds, and I dont want to jump into this without knowledge and get stuck with crappy cams.

Thanks

**edit* posted the same time as you ^ !

I dont think I really want to run N02 just because I want what power I have all of the time (im greedy, I know...) One thing I just thought about was skipping the tm/piston/cams (assuming all would come to around 1k or a bit over) and getting the EFI setup from kms...but those setups only make one/two more ponies than a well tuned 46/45 right?

So many options...so little money [img]i/expressions/face-icon-small-sad.gif[/img]

 

Roost,

The only thing I would have your consider is the idea of a piston. I actually think that a 11 or 12:1 piston is a great way to go. But keep in mind that you wont be able to run regular pump gas. I thought I'd point that out since you originally stated that you didnt want to run race gas. If you have 98 octane pump premium, then the 11.5:1 is a great way to go.

As far as NOx, you may want to think about how you use your throttle. Most people dont run with the throttle wide open all the time - especially in "woods riding". So, having to be able to burst your power when needed, might be somthing to consider - just a thought...

Im not trying to tell you what to do, just a few thoughts to consider for your build.

 

The larger cam you go, the more its moving the power up the curve. Longer duration, less lift will produce more torque I think, and vice versa. Somebody correct me if I am wrong. Higher compression equals more torque in the real world. If you want a great torque monster, and rev at stock rpms, run a higher comp piston, stock cams, and the carb. I have still yet seen an efi setup that is true plug and play, I would wait till they get it right. 1-2 horse over a properly tuned 46hv? Ya i'd have to see that to believe it! I hear you can run 11-1 on 91 at sea level. I run 12-1 on pump 91 at 4500'. And run 100 with 12-1 with nitrous at 4500'. Hope that helps.

 

Jed,

You are absolutely correct, generally speaking, the more you move the cam up with lift and duration, the more the power is also moved up to higher rpm. But, if you simply add NOS by keeping everything else the same, you can subtract that movement upward by about 1000 RPM. I do hear of people running 11.5:1 pistons with regular pump gas. The margins of error are more slim in terms of pre-detonation.

I dont know if you were commenting on my post, but thought I would put that out there. [img]i/expressions/face-icon-small-smile.gif[/img]

 

I was just responding to Roosts post Mark my man. How did you learn about the 1000rpm difference?

 

Jed,

I first heard about it from TheBOM. And it has held true with the other NOx bikes I helped with.

Roost,

If you decide not to run NOx, then I would not recommend the A1A2 cams. I would go with something milder instead. If you want good all around power with a TM45 or larger carb, and 11.5:1 piston, you might think about the lowest Web cams 110 grind or keeping the stock cams you have.

A high end cam will simply not provide the low end torque needed for trail riding unless other power enhancing modifications are used such as the ones already listed.