Looks like everything is coming together as far as picking up the new bike. Should know in a week or two when it's going to be shipped me. Yay!Also, I was looking into that Ecotrons EFI system a little more yesterday. Turns out they have a Bluetooth module that you can hook up to the ECU and a Droid app that turns your smart phone into a Bluetooth data logger. Bitchin'!Scottie
I'm not sure where the idea came from about advancing the cam timing, but a boosted engine typically wants exactly the opposite.
The Garrett GT1241 Turbocharger is well-suited for 0.4 to 1.2 liter displacement applications including motorcycles, snowmobiles and other small frame applications. The turbocharger comes complete with internal wastegate and an actuator. The recommended horsepower for this turbocharger is 50 to 130 horsepower.
Yes, when boosting a motor you want the spark a little more retarded than usual. The idea of advancing the camshafts was more of a thought/question as to whether it would help me achieve a higher RPM redline or not. The trick with turbos, as you probably know Ace, is to get the happy medium between a small enough volume turbine that will spool quickly, but big enough in order to produce respectable boost. Much like your Fireballs, it's not as simple as throwing parts at a motor and saying "That will make 50hp". There is a lot of math (volume figures) that needs to be calculated before the build ever takes place. If it doesn't add up on paper, it will never work well in the real world. Fortunately, Alex knows all these numbers and calculations to base mass, flow and RPMs with the cylinder displacement and head flow.He was also telling me that higher lift cams can help, but with boost, it's more important as to how smooth the air can flow thru the heads/cambers as opposed to HOW MUCH air can travel thru. Because when boosting a motor, you are forcing air into the engine, it is not as important to have a higher lift cam because the air is stilling being forced into the same area. Therefor adding larger valves would essentially have the same effect on a boosted motor as having higher lift on a NA motor. Both are flowing more air, just in slightly different ways.Ice - What turbo charger is that? Always curious about more options. This is directly from Garrett in regards to their turbo I'm looking at, it is the smallest turbo Garrett makes. After using the formula provided by Hitchcocks, I was able to figure out that the actual engine size of a 700cc twin with a +.040 bore with the standard 90mm stroke is good for 746cc, or .746 L. This Garret turbo is actually perfect for my engine size. The turbo from the Ecotrons system is only rated up to 600cc and won't flow enough air to make efficient power at higher RPMs. If I had a Bullet Thumper then the Ecotrons turbo would probably work well, but I'm looking to be breaking some speed records, and for the 1st time ever, I'm ready to throw down some serious dough to build the meanest fastest Enfield ever built.Scottie
I am familiar with the math and the techniques.I'm sure he knows that the intake lobe center angle for a boosted engine is almost always much wider than what is standard on the Enfield twins, and that on boosted engines the exhaust valve is almost always larger than it would be on a normally aspirated engine, along with a more advanced exhaust cam. And that the overlap period is really needed to be very short on a boosted engine with a crossflow hemi, to reduce blowing too much out the exhaust pipe during overlap.Wide lobe center angles are the order of the day for boosted engines.I'm sure he'll agree.
I've heard him mention most of that stuff, I'll definitely show him your message though just to make sure.Ace - Are you familiar with the math for gearing bikes? Is there some kind of formula like HP/speed=gearing for this?Scottie