How to tell if my spyder is running lean or rich?

[LongBeard]

I recently installed a slip on Voodoo exhaust on my 2008 Spyder GS. Removing the stock exhaust deletes the catalytic converter as it is housed in the exhaust itself. I bought a Juice box because I read that it is recommended due to it possibly running lean. I was not able to install the juice box though because the wiring harness would not fit my fuel injectors. I learned after that they do not make a juice box for the 08s nor do they make a power commander, so I returned it. I called the dealer and they essentially told me there is no way for them to tell if my Spyder is actually running lean or not, and there is no way they could get it on a dyno to tune it. The only way I heard is to take out the front spark plug and inspect it for a white build-up or corrosion. I am not getting a check engine light or any difference in performance other than the change in sound from the exhaust but I do not want to damage my baby if it is running lean or rich. Is there any way to tell such as a noise or a difference in performance? Everything is stock other than the exhaust. I am not a mechanic so any input is appreciated, thanks.

[Peter Aawen]

Basically, given the way these things leave the factory, if you haven't got a juice box or had the ECU Upgraded, then it's almost certainly running lean. Tossing the OE Muffler & cat converter, even just reducing the back-pressure a bit will contribute to it running a bit leaner; plus, you'll probably hear a bit more crackling &/or popping on over-run/deceleration too, which is another indicator....

But like I said, if you haven't got the juice box &/or had an ECU Upgrade, then it's running lean... If you've tossed the cat converter/reduced back pressure, it's running even leaner. Maybe it's not too much overall, but it's still running lean - it's done that way by design to reduce emissions.

[Gwolf]

But if you really want to know, most any good auto shop will have an exhaust sniffer that can give a reading that is accurate.

[Mikey]

You need to find yourself a person who can tune your ECU. When you start to play around with your exhaust it's a put and take thing. I am no expert on this, but you want to make sure that you're not running too lean. The computer can only adjust itself so far and you have to know where that is! Good Luck!

[BajaRon]

I've got a Juice Box on my 08 GS. At the time, they specifically advertised the unit for the 08. Not sure why they would say they don't make one. Or why the one you had didn't hook up. Maybe they discontinued it.

[2dogs]

I recently installed a slip on Voodoo exhaust on my 2008 Spyder GS. Removing the stock exhaust deletes the catalytic converter as it is housed in the exhaust itself. I bought a Juice box because I read that it is recommended due to it possibly running lean. I was not able to install the juice box though because the wiring harness would not fit my fuel injectors. I learned after that they do not make a juice box for the 08s nor do they make a power commander, so I returned it. I called the dealer and they essentially told me there is no way for them to tell if my Spyder is actually running lean or not, and there is no way they could get it on a dyno to tune it. The only way I heard is to take out the front spark plug and inspect it for a white build-up or corrosion. I am not getting a check engine light or any difference in performance other than the change in sound from the exhaust but I do not want to damage my baby if it is running lean or rich. Is there any way to tell such as a noise or a difference in performance? Everything is stock other than the exhaust. I am not a mechanic so any input is appreciated, thanks.

Not sure if this applies to you but here goes. I did the same thing to my 14 RT as you did to your 08 GS. First I did the cat delete. No appreciable change in performance or MPG. Only the sound changed, "a little". Then I installed stage II. WOW, what a change in performance and MPG. The performance went over the top and MPG went in the toilet, no change in sound. After a couple of tanks of gas MPG came back to normal but performance stayed up there. Then I got a 2Bro's muffler and the sound was over the top. WAY too loud. I baffled it and got the sound down to a liveable tone. MPG went into the toilet again but came back after a couple of tanks of fuel. So, what I get from this is the ECU (ECM) is looking out for you all the time. Mine only "pinged" once and that's what you want to watch out for. That means it's lean and you may need to run 91 octane to prevent pinging. I kept an eye on my exhaust tip for excessive residue but none showed up and my MPG came back to normal. That tells me it's not running rich. Good luck hope this helps.

[LongBeard]

Not sure if this applies to you but here goes. I did the same thing to my 14 RT as you did to your 08 GS. First I did the cat delete. No appreciable change in performance or MPG. Only the sound changed, "a little". Then I installed stage II. WOW, what a change in performance and MPG. The performance went over the top and MPG went in the toilet, no change in sound. After a couple of tanks of gas MPG came back to normal but performance stayed up there. Then I got a 2Bro's muffler and the sound was over the top. WAY too loud. I baffled it and got the sound down to a liveable tone. MPG went into the toilet again but came back after a couple of tanks of fuel. So, what I get from this is the ECU (ECM) is looking out for you all the time. Mine only "pinged" once and that's what you want to watch out for. That means it's lean and you may need to run 91 octane to prevent pinging. I kept an eye on my exhaust tip for excessive residue but none showed up and my MPG came back to normal. That tells me it's not running rich. Good luck hope this helps.

I ordered two of these: https://www.voodoomoto.com/ProductDe...ductCode=VEPSC today to hopefully help give some back pressure. Also, what do you mean by "pinged"? How much did you pay for your Stage II upgrade if you do not mind me asking, and was it through this company?: https://wick-itperformance.com/shop-...-can-am-spyder

[Mikey]

I ordered two of these: https://www.voodoomoto.com/ProductDe...ductCode=VEPSC today to hopefully help give some back pressure. Also, what do you mean by "pinged"? How much did you pay for your Stage II upgrade if you do not mind me asking, and was it through this company?: https://wick-itperformance.com/shop-...-can-am-spyder

You see that fabric wrapped around that baffle you got? Your going to need to find that material to repack that baffle on occasion! I had a XS1100 years ago that I had to have a new exhaust, so I went the header route, it was great when I first put it on, then a year down the road I could not stand it, ever since that I am a fan of factory pipes! After a few hot suppers that packings going to blow out of there. Have fun, ride safe!

[2dogs]

I ordered two of these: https://www.voodoomoto.com/ProductDe...ductCode=VEPSC today to hopefully help give some back pressure. Also, what do you mean by "pinged"? How much did you pay for your Stage II upgrade if you do not mind me asking, and was it through this company?: https://wick-itperformance.com/shop-...-can-am-spyder

Here's where I started looking for baffles. https://www.ebay.com/sch/i.html?_fro...ffles&_sacat=0 I had to order two baffles and cut them and weld them to fit my application. (You can find really low temp welding rods that work with just a butane torch if you don't have a welder.) Voodoo looks good but I didn't wrap my baffles with packing. The 2bro's muffler already had packing. Pinging is a pre-detonation sound that occurs from fuel igniting in the cylinder before the spark plug fires. This is a very bad condition and can destroy your motor if allowed to continue. (IE; breaks pistons bends rods and valves and so on.) I bought stage II through Wick-It and it cost me $500+. Great modification. Whatever you do if you get stage II, don't let it get away from you when you nail it in the lower gears. Good luck and be safe while having fun at the same time.

[Rednaxs60]

Agree with Peter Aawen, and others that changing the exhaust system changes the engine operating dynamics. The OEM has programmed the ECU to use engine parameters and ancillary component influences (exhaust system being one of these) to meet emission standards and to deliver the correct amount of fuel to achieve the correct air-fuel mixture at all times, it's a package deal. The OEM has delivered a product that is the best compromise for every day operation. Engine timing, dwell settings and the likes are used as well. We have no idea what is inside that black box.

The short answer that I can give is that an exhaust system change can result in a fuel rich - fuel lean condition, or both depending on the new exhaust system design, but now for a short story.

Changing the exhaust system changes the exhaust system exhaust flow harmonics, these go back and forth in the exhaust piping affecting the back pressure on the engine, affecting the manifold air pressure, affecting the pressure differential across the fuel injectors, affects the fuel rail pressure, affecting the amount of fuel being injected into the engine at any given time. This can cause the engine to operate in a fuel rich - fuel lean condition to varying degrees that the ECU cannot compensate for because the ECU does not monitor exhaust system dynamics. O2 sensor readings affect the ECU fuel calculation, but this is always an after the fact impact. No one sensor can 100% compensate for an aftermarket change.

O2 sensor(s) are used in the "closed loop" operation (generally at idle and low engine powers), and are normally in the "open loop" operation at higher powers and do not affect the ECU fuel calculations. A good book to read on this is Stealing Speed by Max Oxley.

The good news is that an EFI system can be calibrated to accept the new exhaust system if you have access to the ECU programming and the programming can be adjusted to bring everything back into line so to speak. If you do not have access to ECU programming, sometimes best to leave as is, but if you do make a change, nice to know what effect it may have on the engine.

We pay a lot of money for our "toys". Aftermarket additions are great, fulfill a personal need to make a product our own, but one has to wonder how the product was designed and tested. I did the same with my '85 Honda Gold Wing FI model. Changed the fuel injectors for a set from an '85 Honda Prelude. Different size, smaller. Injector data is different than the OEM originals. Engine appeared to work well, or did it?

Had the OEM fuel injectors cleaned, flow and leak tested at different shops. One shop indicated an injector flow rate of 280 cc/min, the other 315 cc/min, huge difference. No issues with the fuel injectors using the OEM ECU - OEM system designed to use these, huge difference with the aftermarket DIY ECU. Had the 315 cc/min fuel injector data for the aftermarket DIY ECU, made a difference in being able to start tuning the engine. Think the 315 cc/min is the true flow rate.

Was fouling the plugs on my '85 Honda Gold Wing FI model with the new aftermarket DIY ECU. Found out there are no less than four fuel enrichment percentages used that augment the amount of fuel being delivered to the engine before the engine reaches normal operating temperature. Go figure.

How do I know about this? I am changing the OEM ECU to an aftermarket DIY ECU for my '85 Honda Gold Wing FI model. There is no information regarding the OEM ECU programming, and there are no shops that can do any changes to the OEM ECU.

I like making changes, doing modifications to make my "toys" my own, and would never say not to do so. In mentioning this, the better informed I am, the easier the decision process.

Short story and hope it helps. Nothing is ever simple. Cheers

[LongBeard]

Monster Fuel Injection got back to me and informed me that stage II flash requires a electronic throttle, but a stage I flash can be done. I am going to try to contact them via phone to get some further answers about whether or not this will fix my issue. Thanks everyone for the information. Ride safe!