RX1 w/R1 Fuel Injection - What next???

[K-fab]

Okay, newbie here (man I hate being a newbie again... - new board for me).

I've done a bit of searching on this, but didn't come up with anything that really relates to my setup. (See, I know the rules - search first, especially as a newb, then ask)

Anyhow, here's my setup:
2003 RX1 engine - bone stock except for 2002 R1 Fuel Injection system and an R1 exhaust cam
Dyno Jet Power Commander
K-fab Exhaust System - with a carbon fiber bodied stock R1 muffler (probably restrictive). Header pipes are 1.5" in diam and cc out at 750, on average - so they're fairly close. I'm running a Tri-Y setup that mimics both the sled and the bike - cylinders 1 & 2 into a Y, cylinders 3 & 4 into a Y. Both of these Y's are 2" diam throat outlets and they go into a Y that has a 3" diam outlet. - all tubing is 304 Stainless, .049 wall
K-fab Velocity Stacks in custom airbox
Bone stock RX1 drive clutch
Team Driven clutch.

This is NOT in a sled - it's in a Desert Race Car (see the avitar?)

I'm almost finished installing the engine into the Dez (the car) and I'm looking for some HP.

I replaced an old used and abused Arctic Cat 1000 triple in the car with the RX1. The AC made right around 190 hp, but only 68 ft/lbs (or there abouts) of torque - the RX1 is supposed to make right around 160 hp with 125 ft/lbs of torque. - or something similar, as I know of another off road car with a similar setup (engine & FI, different exhaust) and these numbers came straight off his dyno runs.

Obviously the four stroke's gonna have a wider spread power band and a broader torque range than the two stroke did, so I should have a more flexible power plant now. I've been riding four stroke motocross bikes for the past 6 years, so I understand the difference between two smokes and four bangers, which is a lot of the reason I decided to change to the RX1 engine.

So, what I'm looking for is engine info - specifically ideas on upping the HP and torque, but not to the point of stressing the engine. I MUST have reliability over higher performance. It's NO fun sitting in the middle of the Mexican desert waiting on your crew to come find you. (don't ask how I know this....)

I would like to drop the peak HP and Torque down in the RPM range - I'd much rather run the engine at 8K - 9K instead of 10K all day long.

I can't use any sort of forced air induction. Turbochargers and superchargers are not legal for any of my racing. Must be normally aspirated and no NOS either.

What can I do to make gains? I'm guessing cams, porting, big bore kits???
I MUST keep the engine running on PUMP FUEL - 93 octane. I will NOT run race fuel under any circumstance. Been there, done that and it's a major pain in the #*$&@ - especially in the places that I race. I have to be able to pull up to the pump and fill 'er up.

I'm not stuck using the muffler that I have - it was an e-bay item that was cheap and fit the bill for, if nothing else, the build and install. BUT, the one aspect that I like about it is that it's QUIET. (I'm basing this comment on the fact that stock bikes are quiet, and the muffler says something about not being over 86db) I have not started the engine up yet - still waiting on one more gasket and some finishing work on the airbox.

I've put up with an obnoxiously loud (120+db) car for the past 5 years and now it's going to be under 96 db - even to the point of loosing engine performance if I have too. You have any idea what it's like not being able to hear your own horn??

I also need to find some FI mappings that I can d/l into the Power Commander - at least for a base line. I want to find someplace local that has a chassis dyno AND does Dyno Jet stuff so I can get the engine tuned to peak performance. - I know of a place in Mesa, AZ, but I'm in Ohio at the moment, so that's pretty worthless to me right now.

So, how 'bout it?
Anyone wanna throw me a bone and get a discussion going on how to make this puppy rip but still come home at the end of the day?

 

[LazyBastard]

I don't know where you're getting that 160hp from.. with those mods you have listed, in warm weather you should be around 125-130. Do around 140 in the cold. Fuel injection WILL NOT give you any more power. If you want to get the power up somewhere that you want it, you'll probably be looking for a turbocharger.

 

[K-fab]

I don't know where you're getting that 160hp from.. with those mods you have listed, in warm weather you should be around 125-130. Do around 140 in the cold. Fuel injection WILL NOT give you any more power. If you want to get the power up somewhere that you want it, you'll probably be looking for a turbocharger.

Okay, not to sould like a total knob or anything but, I was asking for help and information, not being told "this isn't it" and "do this" when I specifically stated that I couldn't "do this"...

I took the time to post all the information and specifics of my setup, the rules I'm bound by and the direction I want to go just to avoid this sort of negative, non-informational repy.

Please, if you have information to help me, then do so. If you don't, then don't waste your time or mine.

Yea, yea, I know I'm a newbie on THIS board, but I'm old hat on a bunch of others, with thousands of posts cumulatively, so I carry my "been here, done that" attitude with me here. - sorry if this is unacceptable.

The numbers I listed, as pointed out in the first post of this topic, were off of a dyno - a car chassis dyno. These came from another off road car setup with a similar setup to the one that I now have in my desert car.

I never said that the FI would increase my hp - I want it for the ability to tune with a keyboard, the fact that it's self adjusting to changing conditions and that I race anywhere from sea level to 6000 feet above sea level. No more jet changes is gonna be nice.

And do you not see that I pointed out that I must remain normally aspirated?

Thanks, but instead of telling me what I can't do, how about helpful info? It goes a lot farther instead of telling me I'm wrong or can't do it.

 

[givemeaboost]

Wellcome to the forum! That's a pretty wild ride you're building, it ought to really rip when it's done. Just FYI the 03's had a ring problem that caused oil use issues when they used premium fuel causing the rings to carbon up. You might want to do a search here on oil burning issues.
Your header is a work of art and should be worth some noticeable horsepower. The muffler looks good on there(I've got the same one on my sled) and should sound great. Mine's real quiet but it goes through the turbo which keeps the decibels down alot.
I hope you keep the stock center to center on the clutches so you can use the Yamaha belt because it'll outlast anything else out there. I'm wondering how good that type of clutching works in the dirty environment it's going to be in? Ken.

 

[LazyBastard]

Okay, not to sould like a total knob or anything but, I was asking for help and information, not being told "this isn't it" and "do this" when I specifically stated that I couldn't "do this"...

Sorry dude, your post was so long and rambling that I missed the line about no turbos. Don't get your panties in a bunch.

The numbers I listed, as pointed out in the first post of this topic, were off of a dyno - a car chassis dyno. These came from another off road car setup with a similar setup to the one that I now have in my desert car.

If that engine had only what was done to yours done to it, then that dyno is WAY OFF in its calibration, or the operator has no clue what he's doing.

I never said that the FI would increase my hp

How about this line from that website you posted:

One can adapt the fuel injection system off the R1 bike - instant HP - supposed to be right at 160 and now I don't have to jet anymore!!!

And this one:

With a gain of 15 hp, thanks to fuel injection

Now if you want to boost the power withOUT forced air, you're going to have to get some special rx1 cams, porting, high-comp pistons, etc., then you're going to have to spin it 11k+, and run it on race gas... but yeah, I know, you don't want to do any of that. Just keep in mind that power has to come from SOMEWHERE.

 

[low flying missile]

RX1 engine

You need to search these boards for posts from Supertuner and Dynoray. They are frequent contributors to this site and have extensive knowledge of these engines and how to tune them. Both have attained 180+ hp in naturally aspirated form. These engines are quite bulletproof and many have survived 2or more seasons at 250 or more hp with turbos. There have been remarkably few failures. Don't worry too much about lowering the operating range I think they rev them to 14or 15 thousand in bike racing. One thing I would do right away is look in the classifieds. There was a ported cylinder head with heavy duty valve springs that somebody wanted to get rid of bad. If I had the money, thats where I would start. While you have it apart you can throw in a new set of rings , degree the cams and away you go.

 

[K-fab]

Okay, not to sould like a total knob or anything but, I was asking for help and information, not being told "this isn't it" and "do this" when I specifically stated that I couldn't "do this"...

Sorry dude, your post was so long and rambling that I missed the line about no turbos. Don't get your panties in a bunch.

LOL!! Maybe I like my panties bunched up...
No harm, no foul.

The numbers I listed, as pointed out in the first post of this topic, were off of a dyno - a car chassis dyno. These came from another off road car setup with a similar setup to the one that I now have in my desert car.

If that engine had only what was done to yours done to it, then that dyno is WAY OFF in its calibration, or the operator has no clue what he's doing.

Okay, I can accept this. The info I was given was passed on to me by a secondary party. I trust this person, as he's never steered me wrong, but there's always a chance that the first hand info was incorrect. There may be more done to the engine too? I'll have to ask for more info.

I will look into getting print outs of the runs. The other thing that I was told was that they couldn't hold the car down on the dyno once it started really ripping - has to do with the ATV style tires the guy was running - at 106 mph, they started to blister and throw knobbies around the room. That must have been fun to see.

One thing about the FI setup - with a Power Commander and the dyno, they were able to map in the FI and get gains in the HP. How much? Dunno - 160 was supposed to be the magic number. I don't know much about the exhaust system that is on the car other than it was designed by some guy that supposedly knows what he's doing - then again, there are often many "experts" (expurts??) that don't have a clue.

I never said that the FI would increase my hp

How about this line from that website you posted:

One can adapt the fuel injection system off the R1 bike - instant HP - supposed to be right at 160 and now I don't have to jet anymore!!!

And this one:

With a gain of 15 hp, thanks to fuel injection

Ah, excellent point. Once again, this is info from source "a", if you will. Good to see that you did your homework on what I've done so far (written) and I appreciate you pointing it out.

As I've said, I'm passing on what I've been told. Hell, I've not even started this engine yet. If it ends up that I'm talking out of my #*$&@ - after I get proof with dyno work and such, I'll be the first one to stand up in front of the class and say "I was wrong". I'm not proud when it comes to stuff like that - I'd much rather talk the straight talk and deal with the real, proven, numbers.

I've driven a couple of the RX1 powered cars and they felt great as far as power and delivery goes - these were both normally aspirated, carb'd engines. When taking into account the weight difference between the cars I've driven and mine, the difference in power delivery of the RX1 and the AC1000 that was in mine, well, the RX1 SHOULD work nicely. - and, to be totally honest, I have NO CLUE what the hp of the two normally aspirated RX1 powered cars is. I would guess in the 140ish range, but it was a couple years ago and my butt dyno's not very well calibrated. The torque was definitely what was making things happen. If I can get more HP, I'll be happy to take it.

I have also driven a turbo RX1 powered car - man - that thing went too fast too quickly. I forget what the power was supposed to be - 220 maybe? - and it had a switch that added an extra 20 - waste gate control I believe. The thing ripped. No way it would work in the desert, though.

Supercharging would be the perfect option if it were allowed. No lag, smooth delivery that's connected directly to my foot. Oh well, I'm stuck with a sucker instead of a blower.

Now if you want to boost the power withOUT forced air, you're going to have to get some special rx1 cams, porting, high-comp pistons, etc., then you're going to have to spin it 11k+, and run it on race gas... but yeah, I know, you don't want to do any of that. Just keep in mind that power has to come from SOMEWHERE.

Now this is the sort of info that I'd like to get more of!

I'm not opposed to doing what ever it takes to make more HP, but it must remain reliable - and no, I just can't do the race fuel thing. I know I'm limiting myself on this too.

I don't like the idea of spinning the engine too terribly hard, but in general, I don't see WFO, long straights that often. It's mainly on and off the throttle, point and squirt style driving. The AC engine was set up to turn right around 7800 - 8K, but it probably lived it's life more in the 6500 - 7K range. I would imagine that the RX will see a similar drop in average rpm versus what it can/will do. - hence the reason I was looking to get the peak power down a bit lower in the rev range. - then again, I can/will tune the clutching to put my power delivery right where I want it.

Since an engine is nothing more than a fancy air pump, the more efficently we can make it pump air, then the more hp it will produce. Cams, porting and such will definitely help. Big bore is something else I'd like to find out about too. Unlike two-smokes, our beloved four bangers always respond to increasing the cc's. Got any info on big bore stuff??

One other option that I want to look into, after I get the car on a dyno and develope some mapping, is to upgrade and add the system (Dyno Jet) that controls the ignition and FI curves together. That's supposed to make the tuning even more controlable and increase the engine's output.

I'm on page one right now with this thing. I'm starting just where everyone else starts on a project or new venture: The Beginning.

It'll be fun to see where developement gets me by the end of summer :exc: - hopefully, with help from this board, it will be a ripper engine.

Sorry about coming across as a knob. :ORC

 

[LazyBastard]

You might want to talk to the guys at mountainperformance.com. They've got some goodies that might help you out. Yes I know, their main page is all about superchargers, gotta dig a little deeper. They've got big bore to 1025cc at 12:1 (also have it at 10:1, but thats for blowers). I forget where it is, but I have heard of a place that sells cams for these engines, supposed to get a decent gain with them. You might also want to talk to Freddie (search for username "supertuner"). He's got some magic up his sleeves. I've heard numbers like 180.

Now as for engine rpms... you would probably find on these engines, that they actually last LONGER at higher rpms. 2-strokes tend to blow from all kinds of nasty things at high rpms, particularly detonation, but the main thing that'll do in a 4-stroke is torque. Spinning it faster at lower torque means that there's less stress. Besides, everyone who has an RX1 holds it WFO across every lake they find anyways, and I haven't heard of any engine failures AT ALL that could be related to that. Don't be too worried about high rpms. These engines can take it.

 

[RedRX1]

The 5 valve design is defiantly meant to excel at high r's

 

[K-fab]

You might also want to talk to Freddie (search for username "supertuner"). He's got some magic up his sleeves. I've heard numbers like 180.

I've been pointed in his direction by a couple others via PM's - and have contacted him. It will be interesting to see what he can help me do. Freddie's already given me some good info.

Now as for engine rpms... you would probably find on these engines, that they actually last LONGER at higher rpms. 2-strokes tend to blow from all kinds of nasty things at high rpms, particularly detonation, but the main thing that'll do in a 4-stroke is torque. Spinning it faster at lower torque means that there's less stress. Besides, everyone who has an RX1 holds it WFO across every lake they find anyways, and I haven't heard of any engine failures AT ALL that could be related to that. Don't be too worried about high rpms. These engines can take it.

Great to hear this. - I actually find that I run my four stroke MX bikes higher in the rev range than I did my old smokers. I'm just having to adjust to the idea of spinning this new engine 3K more than I did the last engine in the car.

I know Yamaha designed them to run at high RPM, it's just hard to convince myself that it'll be okay with this new engine.

 

[K-fab]

Wellcome to the forum! That's a pretty wild ride you're building, it ought to really rip when it's done. Just FYI the 03's had a ring problem that caused oil use issues when they used premium fuel causing the rings to carbon up. You might want to do a search here on oil burning issues.

Thanks for the heads up. What's a more permenent fix for this issue? (I know, use the search... ) Can I switch out piston and rings, or rings or ???

Your header is a work of art and should be worth some noticeable horsepower. The muffler looks good on there(I've got the same one on my sled) and should sound great. Mine's real quiet but it goes through the turbo which keeps the decibels down a lot.

Thanks on the header compliment. A buddy of mine actually did all the welding and such. I just helped cut and hold the tubing while we tacked it all together. I'm very pleased with the way it came out too.

I hope you keep the stock center to center on the clutches so you can use the Yamaha belt because it'll outlast anything else out there. I'm wondering how good that type of clutching works in the dirty environment it's going to be in? Ken.

Don't I wish! I'm running one of the longest belts available (sorry, can't recall the size right off hand). I had to work really hard to get the clutches as close together as you see in the pix on my web site. It was a biatch!

As far as dirt goes. - it's surprising how well the clutches hold up in the environment they live in.

Dirt was never an issue for the belt and I never had any problems with the AC driven that I was using. I checked it often for any signs of binding or wear and it was always in good working order.

The driven, on the other hand had a much shorter life.

The first thing I had to change out was the helix and rollers. The stock plastic rollers would last for a day or so before they started getting sticky and not rolling well. Back shifting would suffer. The helix would also start showing signs of wear pretty quickly. Once I switched to the Aaen hardened helix and sealed bearings for rollers, I didn't have those issues anymore.

The biggest issue with the Cat driven was knocking off the towers. I went through a driven about every 1000 miles or so. Whoops (are everywhere in the desert) and landing off jumps while on the gas had a tendency to crack the base of the towers and after a few of these hits, I'd get a nice vibrating, then blown apart driven.

I've switched to a Team driven for this new setup. All the moving parts are sealed away from the outside world, there are no towers and the Team's proven to be very bullet proof with some high hp off road cars.

I'm hoping that this setup eliminates one more weak point of the car.

 

[BURMAD69]

Take better advantage of the horsepower you already have by doing some primary clutch tuning, What we use on our sleds most likely wont work for your application, but it never hurts to try. these engines have a lot of hidden power in the clutches. cdi box to increase revs, if your running R1 parts then spin it like the R1 these engines like rpm's if your cdi will allow it.


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Oh Yea Welcome to the site.

 

[LazyBastard]

Wellcome to the forum! That's a pretty wild ride you're building, it ought to really rip when it's done. Just FYI the 03's had a ring problem that caused oil use issues when they used premium fuel causing the rings to carbon up. You might want to do a search here on oil burning issues.

Thanks for the heads up. What's a more permenent fix for this issue? (I know, use the search... ) Can I switch out piston and rings, or rings or ???

The 05's have different rings, which are stiffer. Generally not a big deal if you keep the engine clean - running it hard tends to be good for it. Also, running it in warm weather is a plus for this issue. Most 03's do NOT have this problem anyways.

 

[K-fab]

Take better advantage of the horsepower you already have by doing some primary clutch tuning, What we use on our sleds most likely wont work for your application, but it never hurts to try. these engines have a lot of hidden power in the clutches. cdi box to increase revs, if your running R1 parts then spin it like the R1 these engines like rpm's if your cdi will allow it.

I haven't done a thing to the primary clutch yet - the only tuning thing I've been told to do is drill out the weight arms w/a 1/4" bit... Uhm, I think I'll do a bit more research and do the mods correctly.

I'm talking to a guy that's also working on a similar setup in his car - he's already way ahead on the clutching.

We're both reading our Aaen Bibles pretty deeply now and I'm hoping the two of us can get the drive clutch dialed in. - I'm hoping he gets his setup first so I can copy it and then work on tuning the Team driven.

It's all R1 electronics (even have the R1 dash) and fuel system, so I'm guessing I'm good to go then.

The 05's have different rings, which are stiffer. Generally not a big deal if you keep the engine clean - running it hard tends to be good for it. Also, running it in warm weather is a plus for this issue. Most 03's do NOT have this problem anyways.

Good to hear. I'm not real nice to my engines - they work for a living when I'm behind the wheel. :exc: - so that hopefully solves any possible oil use problems.

Thanks for the info, guys.

 

[alaskanbowtie]

search for posts by myself and Dynoray about the NA options for these engines, expensive but put ut 200+ h.p. on normal fuel. Cams, porting etc. Also I didn't read everything 'lazybastard" said but he's just like that , smart but always a smart #*$&@. I also know that with the fuel injection and all R-1 stuff you've gained some H.p. don't know how much but some for sure. Fundy power sports is the place that Dynoray works with/owns or something. They can do great things with normally asperated engines. Clutching a MUST and with the load your carrying, I'd do alot of trial and error for that to be what you want, it will be different then sleds for sure. Good Luck and welcome aboard, I bet your around 140 h.p. now maybe more........ Dyno it at the crank to see when you get the mapping done right. Check out boondockers efi box , maybe just what your looking for on the re-mapping your efi. good luck and post your results , welcome !