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Denlasoul
09-11-2003, 10:26 AM
HI there:

ANyone know if there is a difference in im's from a C43 and CLK55/E55? Im curious if they are different diameters or something like that.

THnaks

DLS

speedybenz
09-11-2003, 05:00 PM
DLS,

I dont know if they are different but then your engine may not want a larger intake manifold runner diameter. It could hurt flow. You would have to try it out and see.

After looking at the ports for my C43 I am thinking they are too large as they are and would work better if they were smaller in cross-section.

Jeff

Denlasoul
09-11-2003, 05:30 PM
Thnaks Jeff:

I was wondering, how is the best way to determine if a mod you can buy is actually better for you.

For example, suppose I decide on getting some MKB headers. Outside of before and after dynos, is there another way to quesstimate an increase? Maybe like flow rates or something? Also, with so many different options, how can you tell which is best? Like most people, I dont have the bankroll to buy a product, test it out, not like it, and try another.

There is alot out there for our cars, but I am skeptical of buying something based on someone else's claims. It appears that all your mods are carefully thought out and tested. I would like to go that route too.

Regards,
DLS

speedybenz
09-12-2003, 08:46 AM
DLS,

One way I check some performance mod is look what is working on other cars with similar engine size. The new 4.6liter Mustang engine is a good example. If the header tube diameters of the MKB headers are the same or very close to what good aftermarket people are producing for this car I would say you are safe.

You want to stay away from headers with larger tube diameters.

I would sign up for Autospeed.com. It is a great site full of DIY performance stuff that works and he goes through the testing procedures in detail. Also N2 performance.com is a great site. Visit the library section for very technical write ups on how an engine works.

Buy Smokey Yunicks book Power Secrets. Its a great book on American V8 engines but everything still applies to our engines as well. It even applied to my 15,000rpm superbike engines.

Bottom line is you have to educate yourself so you can tell the BS from fact. 99% of what you hear is BS and it will come from tuners with pretty good reputations. You will soon find out that many of the "So called Tuners" are a monkey see, monkey do type operation and they do not really understand why there product works or doesn't, its just whats been done in the past.

Just remember that your engine is an air pump. It needs to suck in lots of air, mix it gas, burn it and get rid of it. The higher the speed of air flow in the ports the better, which means big ports or headers are not good.

If you have more questions please ask. I sort of rambled on.

Jeff

CKlasse
09-12-2003, 10:09 AM
Jeff,

AIR PUMP indeed, I was looking at a high performance intake manifold for the GM V8s - These new manifolds are OVAL instead of larger round shape. Their research indicates that smaller bore tubes with the same volume capacity as a bigger bore will produce MUCH MORE velocity. In short, two 1" bore will push much more are than one 2" bore. Hence, the oval shape of the manifold (think of combining two 1" bore instead of using one 2").

Furthermore, you see the dual downpipe of the 350Z, they are ovals!

I just thought these are interesting facts for those who's interested in building intake or exhaust manifold :)

Three Point 6
09-20-2003, 08:07 AM
Speedybenz quote,

'4th, you get the head done. You may end up making the intake ports smaller, but with a better shape and since the valve stem is smaller you get more flow'

Read: LS-1 Chevrolet
Chevy's LS-1 has a narrow 15 deg intake path which was considered previous to 1997 as 'un-streetable' on only for racing. They achieved this with a very tall, narrow, unshrouded path into the combustion chamber. The idea was re-hashed from the late 60's Buick V-8 designs that had amazing torque/hp figures(they had 23 deg entry angles though?) That is why the LS-1 pushrod motor makes such high end hp! The philosophy is, let the air do what it wants to do, and that is one reason this motor is considered such a marvel over the previous 50yr old design.

Notice the 'church steeple' shape - wickid...... http://www.corvettefever.com/corvettefever/techarticles/p66907_image_large.jpg

Anybody got pics of MB intake ports? C55, C43, C36,

CKlasse
09-20-2003, 12:29 PM
Yeah, that's the shape I am talking about! That's just sick. Now they are available for the 350 and just about anything GM.