Are log designed manifolds that restrictive?

[nocutt]

...
What kind of effect does the firing order play when you are talking about a turbo and the manifold/header design? I would expect the 1 2 3 4 5 6 firing order to work better either way having alternate firing on each bank compared to alternate/sequential firing orders between banks for other V6 and V8s. Inline 4 would be 1 3 2 4 right? I don't know what variations there are for a 4.

It is not so much the firing order but the way the exhaust pulses...if you noticed the cylinders fire once per bank...so no two cylinders on the same bank are opened together...which is typical on most v8s and 4 cyl...(this is seen usually as reversion, etc)
So from this principle, you either take advantage of these pulses or not (I guess this is where the application comes into play...)
In any event, manifold/header design will rest the type of turbocharging one wishes to do...two theories out there are "pulse turbocharging" and "constant pressure turbocharging"...

[SappySE107]

How can you have constant pressure when the engine has pulses? Perhaps that would be using all 6 pipes to 1 collector? Sounds interesting.

[nocutt]

How can you have constant pressure when the engine has pulses? Perhaps that would be using all 6 pipes to 1 collector? Sounds interesting.

Exactly...although there are situations were both systems can be hybridized taking the advantage of each systems and minimizing the disadvantages...

Here is the link to the SAE paper I already provided the author of this string...

http://ir.sun.ac.za/dspace/bitstream/10019/165/1/BestW.pdf

good stuff...

[gectek]

actually with the waste spark system, each cyl on each bank fires 2 times

[SappySE107]

That doesn't matter for the exhaust pulses.

[gectek]

yah i was just informing the other guy... should have quoted him tho

[--X--]

you guys I appreciate it, this technical stuff seems over my head but after reading more into it I think I am getting it
nocutt ince you are aleady in here, do you mind to clarify why you decided to go with your setup? I am asking because in one of your emails you had stated "pulse turbocharging" does create more backpressure, which makes more sense!

[nocutt]

...nocutt ince you are aleady in here, do you mind to clarify why you decided to go with your setup? I am asking because in one of your emails you had stated "pulse turbocharging" does create more backpressure, which makes more sense!

Oops...
well I was actually going with tubular headers till I ran into a Bank's turbo system (diesel and gasoline). After talking to the Engineers there I also decided to do my own research as I already mentioned to you, what I found was varying results but mostly based on bias and/or mis-information. In any event, I decided that since in my case my engine was a good candidate to this idea why not give it a try?
So WCF (Chris West/www.westcoastfiero.com) built me a "log style manifold"
here
I call it a 3 pulse system, if one cylinder fires 120 degree from the next in sequence; one bank fires 240 degrees apart...in effect these pulses follow one another evenly spaced...also one bank never "sees" interference from the other bank as these pulses are 'divorced' due to each bank's secondary piping terminating in a divided housing
The benefits are already stated in the article posted, although we also incorporated elements of the constant pressure system. Obviously diesels and most street turbocharged 8 cyl do not turn a lot of RPM, these systems can run into a lot of backpressure when they do...pulses need to be spaced evenly, when turning more RPM this diminishes...mind you, this is very dependent on the type of pulse system one is running...

[--X--]

Oops...
well I was actually going with tubular headers till I ran into a Bank's turbo system (diesel and gasoline). After talking to the Engineers there I also decided to do my own research as I already mentioned to you, what I found was varying results but mostly based on bias and/or mis-information. In any event, I decided that since in my case my engine was a good candidate to this idea why not give it a try?
So WCF (Chris West/www.westcoastfiero.com) built me a "log style manifold"
here
I call it a 3 pulse system, if one cylinder fires 120 degree from the next in sequence; one bank fires 240 degrees apart...in effect these pulses follow one another evenly spaced...also one bank never "sees" interference from the other bank as these pulses are 'divorced' due to each bank's secondary piping terminating in a divided housing
The benefits are already stated in the article posted, although we also incorporated elements of the constant pressure system. Obviously diesels and most street turbocharged 8 cyl do not turn a lot of RPM, these systems can run into a lot of backpressure when they do...pulses need to be spaced evenly, when turning more RPM this diminishes...mind you, this is very dependent on the type of pulse system one is running...

email sent will be calling Chris