intercooler testing done

[Prof J]

lol, thanks

I like the stock wheels. I have BST's on one of my other bikes im not sure if I will add them the H2sx or not

David, what are your thoughts on your BST reasoning/choice?

im not sure what you are asking me, I actually have BST's on order for it

Was hoping you had them installed, and what your thoughts were on them about any differences you felt/experienced.

[vcyclenut]

not on the h2 yet , they are ordered but I don't have them , but considering the wheel weights on this bike are relatively heavy to the my 1299 that had the upgraded forged wheels on it I can tell you they make a great difference in the bike

make it stop better, go better, turn easier and make it easier for the suspension to do its job. Its quite remarkable the difference it makes. This will be my 3rd set of BST's

I can get you a great price on them if you decide to get them

[Prof J]

not on the h2 yet , they are ordered but I don't have them , but considering the wheel weights on this bike are relatively heavy to the my 1299 that had the upgraded forged wheels on it I can tell you they make a great difference in the bike

make it stop better, go better, turn easier and make it easier for the suspension to do its job. Its quite remarkable the difference it makes. This will be my 3rd set of BST's

I can get you a great price on them if you decide to get them

Thank you,I appreciate that. I'm looking forward to your review posting after you get them installed.

[Racer-X]

Could someone please explain the advantage of having the intercooler? I get that the cooler the air the more dense and hence more oxygen so more power but is that all or is there some impact to the longevity or health of the engine when the intake temps rise?

ie would you damage the bike if you were to do a trackway and ride it hard all day without an intercooler?

[vcyclenut]

Could someone please explain the advantage of having the intercooler? I get that the cooler the air the more dense and hence more oxygen so more power but is that all or is there some impact to the longevity or health of the engine when the intake temps rise?

ie would you damage the bike if you were to do a trackway and ride it hard all day without an intercooler?

I am going to pretense this with this is my understanding of everything and I am not a mechanic and may have some details not exact but overall this is what is going on.


Any time you increase pressure you increase temperature. Its just physics nothing you can do about it.

so as we are spinning the motor and spinning the impeller on the supercharger and making boost we are increasing the temperature inside the airbox above ambient. Put you temperature gauge on boost temp and watch it go up even when cruising at highway speeds, now do a couple pulls and watch it.

as this temperature increases and the temperature of the intake charge is increased we increase the likelihood for detonation. Detonation is when some of the charge starts to ignite prior to the actual spark plug firing. detonation many times is silent but can sound like marbles. Detonation is VERY BAD for a motor. It puts lots of extra forces on parts like piston tops and connecting rods.

We are lucky enough to have knock sensors on our bike that detect knock, as its happening, and pulls a bunch of ignition timing out to protect the motor. Power drops significantly as it pulls timing. It always pulls more timing then needed to be safe. Still this means you did have some detonation.

any times the intake temps are over around 160 degress your bike is pulling timing to be safe

so to answer your question the intercooler allows for more power to be made and provides a nice level of protection against detonation. When I did my 203 mph run my intake temps were in the 150's. Pre intercooler on a 192 mph run they were in the 190's. My recommendation is if you run your bike hard you should install a intercooler. I don't sell them and gain nothing by making this recommendation.

[danham]

David,

I'm a former Porsche/Audi tech and NIASE certified and just wanted to say that your explanation appears to be very accurate. I would only add that modern knock sensors (in general; I have no direct knowledge of the ones on our bikes) can detect detonation so quickly -- part way through one turn of the crankshaft -- that there is little or no chance of engine damage. But as you say, performance suffers.

One small correction -- with my own over-simplifications. Your mention of fuel charge detonation happening before the plug fires is actually the definition of pre-ignition, which unlike detonation is caused by hot spots (such as glowing carbon deposits) that torch off the mixture too early. Detonation is when the charge fires in a location outside the normal flame envelope, usually right as the plug sparks, but still too early in the piston travel. In other words, a normal charge event starts at the plug and travels slowly (in engine terms) to fill the space with high pressure that drives the piston down. I say "slowly" because it is less rapid than an explosion, more a very rapid burn. Detonation makes that happen too soon and is an explosion, hence the pounding on the piston crown which can have a force of several tons and makes the rattling noise we hate. Detonation happens under high chamber pressures (think supercharging) and temperatures (think no intercooler). Pre-ignition can happen at much lower temps/pressures.

This is why retarding timing can "fix" detonation because the whole show begins later. But it can't fix pre-ignition because the timing does not affect a glowing chunk of carbon in the chamber.

-dan

[Champ87]

Excellent response dan. In the video link below, Kevin Cameron provided an excellent explanation (as he always does) of the differences.

Link:

Kevin Cameron - What Is The Difference Between Normal And Abnormal Combustion In A Motorcycle Engine? - Cycle World

[Racer-X]

Thanks for the detailed explanations guys! A wealth of knowledge on this board as always

[danham]

Excellent response dan. In the video link below, Kevin Cameron provided an excellent explanation (as he always does) of the differences.

Link:

Kevin Cameron - What Is The Difference Between Normal And Abnormal Combustion In A Motorcycle Engine? - Cycle World

Love Kevin's writing, especially when he reminisces about the old days and the H1s at Arlington (MA) Motorsports. A friend bought a 750 triple from them and had them put on a beefy Barnet clutch and some pipes and riding that bike left me with indelible fear and soiled undies.

So thanks for the kind words and the link.

-dan

[Champ87]

Love Kevin's writing, especially when he reminisces about the old days and the H1s at Arlington (MA) Motorsports. A friend bought a 750 triple from them and had them put on a beefy Barnet clutch and some pipes and riding that bike left me with indelible fear and soiled undies.

If you rode one of those triples now you'd probably wonder what the fuss was about. I have an H1E that I'm rebuilding (slowly). When it's done the only fear will come from the terrible handling, weedy brake(s) and appalling gas mileage. One thing in it's favor - it will remind me how far things have progressed.