Gutting my cat


Well, I suppose if you don't like the heat blowing on you, you could always run the fans backwards so that they draw the hot air out the front of the bike rather than blowing towards the back of the bike. :rolleyes:

ASK ANY GL1800 OWNER LIKE ME AND SEE HOW WELL THAT WORKS :mad:
IF YOUR STOPPED FINE BUT 10-15 MPH :eek::eek::eek::eek::eek:
 
dont do it

Never gut out your cat! Its really doesnt do much as in performance. Its better to do the R6 header mod. Also if you not worried about your oem exhaust cut it from the cat back and have a muffler shop weld on a slip on.
 
Never gut out your cat! Its really doesnt do much as in performance. Its better to do the R6 header mod. Also if you not worried about your oem exhaust cut it from the cat back and have a muffler shop weld on a slip on.

You must not have read the thread. Why would i pay a muffler shop to weld when i have my own MIG??? Also why would you be anti - gutting but at the same time recommend cutting it off entirely? I want to retain the stock muffler sans CAT.


EDIT: I also mentioned above that I do infact have the R6 Header ordered already.
 
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Cars to motorcycles , cars make more power with a cooler T-stat .
190* to 210* is normal for a car , 160* makes more power .
I tune my truck fans to come on at a cooler temp to keep the engine cooler to make more power .
Of course if you turned on the heater at stop lights it would be the same thing wouldn't it ?
Higher temps burns fuel more efficiently/completely so they say .
Go to the drag races , as the temps get cooler in the evening the cars get faster , why , because cooler temps make less power ? No , more power .
 
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Mine likes to stay around 198. The highest I have seen it go was 218.
But I'm using a blend of the stock coolant and Prestone.

As goes for the exhaust heat....I have never had that problem. I can temp gun my exhaust and see how hot it gets.
 
Mine likes to stay around 198. The highest I have seen it go was 218.
But I'm using a blend of the stock coolant and Prestone.

As goes for the exhaust heat....I have never had that problem. I can temp gun my exhaust and see how hot it gets.

Well i'm in the Southeastern US so we deal with ALOT of HOT HUMID days. They will tax a cooling system's efficiency to the max. Also keep in mind that i'm used to my V-twin Honda Shadow, and Suzuki SV650, as well as my CBR sooo...
 
Go to the drag races , as the temps get cooler in the evening the cars get faster , why , because cooler temps make less power
That actually has nothing to do with the engines running hotter. It has everything to do with the density of air, cooler air is more dense, therefore you can add more fuel to the mixture. That is where the extra power comes from. That is also why they run world speed record runs in the cool mornings. Denser air means more fuel which means more power.
 
^^^This

Thanks!
 
Catalytic converters don't start working properly until you've ridden about 7 miles. They are supposed to get hot to burn up exhaust emissions. I would leave the cat alone.
 
Not sure why the cat/no cat stuff is going on... Any of you with an aftermarket exhaust has no cat. Aftermarket exhausts are free flowing for a reason for better performance. Also with no cat now though, you may need to do a PC to adjust your fuel/air stuff. Same as going to an after market/no cat exhaust.
 
Correct on the cooler air. That's where the extra power comes from. As for running the bike engine temp cooler, that's messing with how the ecu will function based on the new temp readings. The ecu monitors the intake air temp as well as the engine temp and uses that to alter the default MAP settings. If you run the bike cooler, you may cause the ECU to alter the air/fuel settings under different conditions (a fuel map is based on RPM and intake pressure).

This is not to say that running it cooler will be worse or better. You would have to do it and toss it on a dyno and see. It may find it cooler and rich up the mix a bit, possibly getting better performance, worse MPG. It may rich it up too much and you end up not buring as well and lose power AND mpg at the same time.

They spend a LOT of time setting up these maps based on this, as because our bikes don't have an O2 sensor, we have no real way to adjust the mix on the fly based on the actual output from the engine (exhaust).
 
Hmmm , cooler engine , doesn't make cooler air , weird .
True Ambient Air temp makes a lot of difference , but there are a lot of computer controlled car drivers that will tell you heat soak is a PITA .
A cooler intake makes for cooler air , at any Ambient degrees .
I don't have a manual on the bike as of yet but , in automotive terms there are more factors than just air temp , engine temp , I don't know what the bike has as far as monitoring devices ie ... MAP , MAF , IAT , IAC , CTS , but I would bet it is not as complex as a Automotive Computer .
CATs are emission , nothing else , EPA junk .
 
Hmmm , cooler engine , doesn't make cooler air , weird .
An engine doesn't make air, it sucks it in the intake manifold, rather quickly too. Ambient air temp is the key, not how warm the coolant temp is. Air coming into the intake manifold doesn't hang around long enough to pick up much heat from the engine, and it doesn't come into contact with the coolant. Heat soak is a different problem, and not even associated with an engine that is running, but an engine that has been shut down. When the engine is shut down, it allows the engine to soak heat because the cooling system isn't working and the engine has a lot of residual heat that isn't being removed by the cooling system. The factory set up the ECU to run within a certain range, messing with it will not make the engine run better. I submit that the factory engineers know more about their engines then the average guy. That being said, doesn't mean you can't get more power out of it, but there is always a price to pay for for messing with what the factory designed the engine to do. Could you get more power out of this engine, sure you can, but you will pay a price somewhere. Changing the coolant temp isn't going to get you the power your looking for. Just as running the oil temps lower will get you a messed up engine that never got a chance to eliminate water from the oil. If you wanted a hot rod, you picked the wrong bike, not that this bike is a slouch, after all, it turns low 12 second quarter miles. Not to bad for a 600cc bike. You are right about the CAT being just an emissions device, however our bikes are designed to run with one, sure you can take it off, if you will run any faster it will be because you removed some weight. Removing the CAT may cause less restrictions in the exhaust, but if you don't increase the fuel mix with a fuel nanny, you will run lean, and make less power.
 
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I think in regards to heat soak, what most auto's (track racing) talk about is the heat soak that happens on things such as superchargers/turbos and their intercoolers. Especially if they are air-water-to-air types. I have one on my 92 Supercharged Miata running 12 psi. Heat soak is an issue, as the unit is only capable of removing a specific amount of btu's per min and when I race it, after about 15-20 mins, the unit water temp for the IC goes up dramatically to the point where the ECU will shut down the engine. Solved this with a water injection kit, but you get the point.

As for the bike, the flow of air doesnt have the time to heat up.

I don't know what sensors we have on the bike, most ECU will require engine temp as well and intake air temp (and velocity) to properly adjust the fuel map. If it doesnt (I would be surprised) then cold air induction wouldnt help as more air is only useful if the ECO can detect it and adjust the A/F ratio to take advantage of this. Thats why most cars require a retune after adding cold-air systems as the ECU can't adjust enough to compendate for the change. But again, I would be surprised if it didnt have an intake temp sensor.

As a person that has changed EVERYTHING to get more HP, from cams to superchargers to ECU, valves, headers... there is a cost for everything.

Factory engines are set for reliability and drivability 1st for foremost. Power usually comes after that and nowdays, even for bike, after emissions requirements!

So, there is room for improvment, but you will end up with a tradeoff. For me, I love the tune, that's a real reason why I picked it. Smooth low and mid power delivery, where I spend 95% of my time.
 
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It is with a heavy heart that i concede defeat for the time being. I made GREAT progress on hollowing out the cat, but ran out of time and patience. For now she has a straight pipe off the header. It's loud as all hell and damnation, BUT - The bike definately runs cooler! It heats up at lights slower, and cools more quickly when you get going again. The general radiant heat when sitting still is greatly reduced as well, so that's the good news. Throttle response seems better, no noticeable power gains, per se. Besides without a dyno any gains could be nothing more than placebo effect.

Either way me happy for now with the heat problem solved. Now for the R6 header...... :D
 

One more thing... (it kind of hit me this morning) This bike is equipped with a heat exchanger. (mean the water warm up / cool down the oil) So running the bike too cold will bring the oil temps too cold too. Big NO NO! If the water is around 200F, that mean the oil should be around 220F. This is right on target! It might go up a bit when you're at a stop light but it's ok, no big deal.

This is why engineers invented thermostats so the bike stays in the appropriate temperature RANGE.
 

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