Dyno proven 675-700 HP 540CI recipes?
08-06-2015, 07:29 AM
#301
Registered
I hear ya on the noise. Icdeppl had stellings steroid headers, that were huge. I believe they were 2.25 primary ID, with 2.5" or 2.75 outer jacket , into 5 inch dry tails. With twin blown 540s, they were nasty loud when the mufflers were off it. He has switched to gen 3s, and still full dry tails. Its still loud, not sure if they are as loud as the big steroid headers though. I have the regular stellings on mine, with 4.5 full dry tails. It too can be pretty loud, esp when you start getting into boost.
Loud is cool, but it gets old as well. Esp when you are at the ramp/dock trying to tune or fiddle with something. People get pizzed off much faster than they would if you had a pair of 454 mags and wet exhaust.
Loud is cool, but it gets old as well. Esp when you are at the ramp/dock trying to tune or fiddle with something. People get pizzed off much faster than they would if you had a pair of 454 mags and wet exhaust.
VIP Member
12-11-2015, 06:01 PM
#305
Gold Member
Gold Member
Okay, so what happens during overlap when someone is using wrong collector length (btw: if your riser/tailpipe is same ID as your 'collector', then they too are part of the collector) and right when your exhaust valve opens, an big exhaust energy wave on it's return path enters thru the exhaust valve into the combustion chamber ?
Answer: You re f*ked and the engine become a turd.
It's all about the energy wave timing while your exhaust valve is open...especially during overlap.
When you exhaust valve opens, a large pressure wave shoots towards the atmosphere. When it hits the atmosphere, some of it comes right back. It's physics. This pressure wave goes back and forth, back and forth, slowly decaying in energy. Again, it's physics. We do not want this pulse/wave to hit the xhaust valve when it opens. We want it to be going toards the atmosphere and we want it to be doing so during overlap, to help as much fresh air/fuel mix to be in the combustion chamber when it becomes trapped.
We can call overlap the 5th cycle...on a 4cycle engine.
As I keep saying, like a broken record, with a NA engine, the more cam (overlap) you add, the more important it is to get your exhaust correct.
Answer: You re f*ked and the engine become a turd.
It's all about the energy wave timing while your exhaust valve is open...especially during overlap.
When you exhaust valve opens, a large pressure wave shoots towards the atmosphere. When it hits the atmosphere, some of it comes right back. It's physics. This pressure wave goes back and forth, back and forth, slowly decaying in energy. Again, it's physics. We do not want this pulse/wave to hit the xhaust valve when it opens. We want it to be going toards the atmosphere and we want it to be doing so during overlap, to help as much fresh air/fuel mix to be in the combustion chamber when it becomes trapped.
We can call overlap the 5th cycle...on a 4cycle engine.
As I keep saying, like a broken record, with a NA engine, the more cam (overlap) you add, the more important it is to get your exhaust correct.
12-15-2015, 02:18 PM
#306
Registered
iTrader: (1)
Not to hijack, but if I needed especially long tail pipes (of unequal lengths) off Eckert manifolds, would you decrease tail pipe diameter to keep velocity up or increase diameter to slow gases down and make tail pipe not part of collector? I've been worried about just what you said here. I have side exhaust and inboard manifold outlets are a long way from exhaust exit location. I want to try to equalize exhaust pulses between both banks.
If you want to make the tailpipe not part of the collector, ie: taking the tailpipe out of the tuning of the exhaust, you'd have to make what's called a termination box after the collctor. The box is of a specified size that acts just like dumping into the atmosphere. Without figuring out the size of the box, i can tell you you wouldn't have room to install one in the engine compartment.
If you want, you can PM me all your engine specs and I can see what best size and lengths (there are multiple 'best lengths' for all engines, just as there are multiple 'worst lengths' for all engines) are for your 'collectors' including the tailpipes.
08-07-2016, 05:29 PM
#307
Registered
iTrader: (7)
I just had to bring this thread back up only cause I was looking to see if there was any 565 recipes that I should potentially reconsider for my builds. I didn't read every post but several of them. What I got out of most of it was nothing to do with the thread for the most part. With that said it seems as of reading some other recent post I recall OP took pretty much all the great advice he was given and what happened? So to the "OP" after all the bs and money spent what would your input be at this time be to the original thread. Not to raise your blood pressure or to bash anybody but just honest opinion. I only ask cause I am up against same thing with 555/565 NA builds.
