Steve Arndt wrote: ↑Wed Apr 03, 2019 7:32 am
E120 is a lot of cam for stock valve heads on a small engine. I would advise choosing a better modern grind.
I'm sure that there is a better grind out there, but the 120 is proven to make power to 6300rpm (More with boost as we are forcing the engine to flow more). Plus I already have one with matching lifters.
How much difference do you think valve size makes on a forced induction motor? From what I've seen, its not nearly as much as some would think.
When you forcing air into a motor vs. sucking air into a motor (N/A), Valve size doesn't play as much of a crucial role.
buguy wrote: ↑Wed Apr 03, 2019 7:26 am
I think when most recommend bumping compression to make a cam work better they are talking NA.
Not necessarily, too little compression with a large overlap cam and the turbo will be working overtime to fill the combustion chamber. This would in turn cause higher charge temps which would make the engine more prone to detention. That's why the dynamic compression is so important. With a higher static compression ratio, you are using that extra compression to fill the combustion chamber during overlap.
I have always been taught to get away with a much compression as possible so long as it doesn't detonate. This is within reason of course.
Think about it this way, low compression with large overlap is like a professional marathon runner running a race is wooden clogs
I fully agree, BUT, they also recommend pushing it to the edge because of no boost. Add that turbo into the picture and your compression will go through the roof in a hurry.
That said, I don't own a turbo motor with less than 9:1 static. I also have fully embraced technology though, efi, intercooler, meth injection, and usually e85.
buguy wrote: ↑Wed Apr 03, 2019 7:26 am
I think when most recommend bumping compression to make a cam work better they are talking NA.
Not necessarily, too little compression with a large overlap cam and the turbo will be working overtime to fill the combustion chamber. This would in turn cause higher charge temps which would make the engine more prone to detention. That's why the dynamic compression is so important. With a higher static compression ratio, you are using that extra compression to fill the combustion chamber during overlap.
I have always been taught to get away with a much compression as possible so long as it doesn't detonate. This is within reason of course.
Think about it this way, low compression with large overlap is like a professional marathon runner running a race is wooden clogs
I fully agree, BUT, they also recommend pushing it to the edge because of no boost. Add that turbo into the picture and your compression will go through the roof in a hurry.
That said, I don't own a turbo motor with less than 9:1 static. I also have fully embraced technology though, efi, intercooler, meth injection, and usually e85.
Thank you for your feedback Chip. We will see how this all works out. As I'm sure you already know, keeping fuel ratios and timing in check will be key.
I have none of what you mentioned
Boost referenced fuel pump with o-ringed shaft, turbo prepped DRLA 36 and 009 distributor with a limiting screw. Is this all old school? Yes of course; Does it get the job done? Absolutely.
The whole point of my beetle is enjoying the simplicity of it
Steve Arndt wrote: ↑Wed Apr 03, 2019 7:32 am
E120 is a lot of cam for stock valve heads on a small engine. I would advise choosing a better modern grind.
How much difference do you think valve size makes on a forced induction motor? From what I've seen, its not nearly as much as some would think.
When you forcing air into a motor vs. sucking air into a motor (N/A), Valve size doesn't play as much of a crucial role.
I'll be testing that theory in a week or so. I'm putting my 40X37.5 heads on without any other changes so I can technically do a dyno run and check the differences.
I'll definitely test it with my butt dyno though.....
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.
John S. wrote: ↑Wed Apr 03, 2019 10:53 am
Frank,
Did you get all the drivability issues out of the single dell set up?
I honestly cant complain about too much. It runs really good cruising, part throttle and full throttle. My only complaints would be the lack of choke and an occasional small stumble when first hitting the throttle.
Splitdog wrote: ↑Sat May 25, 2019 5:15 pm
Cylinder pressure being the same, high boost/low compression will make more power than the other way around. I run 7:1 on 91 with 15 lbs.
Let's do two extremes for comparison. Say you have an 11:1 compression N/A motor. What is the cylinder pressure at TDC? Now say you have a 7:1 compression motor. But you boosted so that at TDC the effective cylinder pressures are the same. The second motor will make more power. Why? Because you're burning more fuel and air. Boosting increases displacement, compression doesn't. 15 lbs boost is double the natural air pressure. So at 15 lbs boost, you're effectively doubling your cc. So my 2165 becomes like a 4330 cc motor. It is moving that much fuel and air through. Now everything isn't exactly efficient, so my motor isn't exactly like a 4330cc, but you get my point. My engine runs fine at 7:1 off boost, too. I would never build a 9:1 or 10:1 and boost. Because you WILL have detonation problems. Do the math; if you ran 10:1 and boosted 15 lbs. the cylinder pressure would be insane. I hope this helps.
