NZ951

Yes if you get a guy that cant port the head, you will go backwards, Im not recommending that lol, you can flow test to prove the gains...

drbooba1

I would be interested in the thread link where the engine developed a hesitation an high speed or high rpm
and finding out what fixed his problem. I would not think FVD or any other sales organization would venture into a radical camshaft profile the would cause that behavior and or that it would need to be remapped.
Remapping only if the RPM threshold is increased beyond what limits the OEM program sees fit, and it would be highly advisable with the 996 platform that one would not do such a risky thing.
One really needs to know what he has timing and duration wise and what he will be buying. it looks in the FVD specs posted that the intake lift at TDC numbers are transposed one to another.

regards

Tbred911

I have an email out to Porsche regarding the stock 3.4 camshaft values... once I get them I will post.

With respect to porting the head that is what FVD told me... I'm sure there is an explanation for it and don't doubt that porting works but in this case they advised against it!

thx for everybody's help here... I'll re-post what I find.

Tbred911

thx logray for that! certainly answers my questions about the power curve... wow their package looks to be quite the upgrade.... (!!)

torque everywhere and loads of it above 4000 rpm...

logray

Flat 6 can make an engine with enough torque to make your eyeballs suck into the back of your head.

As for the cam profiles, they are in various docs, 1. workshop manual (google) 2. Porsche technical training manuals (available at renntech.org for contributing members).

Also the profiles have been posted here in the past.

I would be very surprised if Porsche releases this info to an end user.

Tbred911

I don't doubt what Flat6 can do.... I'm looking for an upgrade at a fraction of the cost or an engine rebuild... cost is a constraint here... and from the graph the FVD solution looks good... would like to find somebody who has done it and running with it for a while to confirm though....

NZ951

To suggest not to port with the head out, is a bit odd, clearly they dont do the work, so nothing to sell.

neffets

A friend of mine did the complete fvd upgrade last autumn, cams, headers, mufflers, air filter kit, and ecu upgrade.
Short story, at first it didn't work when it came out of the porsche shop, he took it to another porsche shop, and they found the timing to be off...
So now it works perfectly, and you can definetly feel the difference.
We will probarbly try to compare with a stock 996 3.4 soon to see how much the difference is when driving/accelerating

Tbred911

I looked into this and apparently porting the head is only worth 5 hp

logray

None of these mods by themselves are going to add massive horsepower.

Only when you put them all together.

If you are looking for massive horsepower or torque you need to look at forced induction, or better yet, sell the NA and buy a Turbo.

NZ951

Pretty hard to look at that in isolation, just about a system of changes. If you take the perspective the engine is an air pump, the CFM through that pump is critical. It also depends if the comp is raised in the headwork, and how many cc are taken out etc. Either way, your penny.

Tbred911

Both FVD and another shop have stated headwork ain't worth it. There is still much cfm in overall system to gain even without headwork! Look at the fvd torque graph. Looks good to me. And that is without headwork.

NZ951

Well if its a matter of being worth it or not, cams arent worth it either... for the USD6.5k they ask for their setup, I could turbo my stock motor and make 50WHP more all day.

http://www.fvd.de/us/en/Porsche-0/-/...LBF-FT%29.html

Tbred911

what something is worth is different to different people.... if you strapped on a turbo the car ain't built for it and you couldn't track it reliably... this is why we stay normally aspirated... as far as a gain goes it's quite a nice gain when you look at the graph... all over the curve... not peaky.... this makes 288 ft/lb of torque... very close to what a 996 GT3 puts out... maybe a little narrower powerband but that's a lot of torque for a 3.4

Tbred911

Steffen,

do a roll-on from 2nd gear @ 3500 rpm and then the same test from 3rd gear @ 3500 rpm right till 7K rpm ... should be interesting...