The HP gain is extremely questionable on the 997TT, lots of big claims with no reproducable numbers. At this point in time the plenum is pure snake oil on the 997tt. Lots of BS chassis dyno smoke and mirrors, zero engine dyno numbers.

 

[quote=roadsterdoc;2251162]No, the pic is the GT2 expansion intake manifold. It is an entirely different setup...




in the the 80s BMW Alpina B7 turbo with the 6cyl 3,5stroke engine has a system like the Porsche "expansionssystem"

This system has a effect that the ignition on high output could increase 7points and the engine has more power in low rpm.......but you must go higher with boost to have the same power in high rpm......

This system from 997gt2 need a boost of 1,4 .....and i think the ignitiontiming must be tuned special for this "expansionssystem" For real high power output my understanding is that this system isnt to extend....you see a standard 997 gt2 with 1,4bar has 530hp.......what boost do we need with this system at 800hp like many members in this forum has on a 996tt ?

 

I'm not 100% sold on them as of yet either. Still need to test one, but even if I did receive significant gains, the price per HP given the fact to me it's likely the highest "Porsche taxed" part I've seen.

The above intake setup however will remove MUCH more restrictions that the factory ducting causes and will likely produce much better results, however this will also come at a likely considerable cost increase per horsepower as well.

 

This is one Mod I am skipping for now. IMO, It's either ALL or NONE, meaning intake before turbos and intake after turbos. I think we need to be in the 600+ whp dept to even consider this a noticable and cost effective option, especially with the bigger garrett turbos. Just my .02

 

lets say you already have the bigger turbos, but the flow is limited to diameter, even without the power wouldn't opening up the flow to the turbo and out make the turbo spool up quicker and generally work better, and run slightly cooler since it isn't having to work as hard, due to less resistance? I would think that if the engine is out, this mod would be a no brainer on any turbo bigger than stock turbos.

 

Ding! Ding! Ding! Give that man a cigar. The air inlet system will be restricted by its weakest link, BUT is not all-or-nothing...you can see some gains by improving individual parts, but to see significant gains everything must be upgraded. This is expensive, but that's what should be done for GT30 size turbos and up (to go above 600whp).

I would say the intake upgrade path goes as follows. Prices are estimates and vary depending on which product you choose, for example #4 from EVOMS for $2K or the SCarGo full carbon fiber setup for $4K. Don't forget labor cost:
1) air filter/air box $75-$900+
2) DVs (for reliability) $350+
3) intercoolers (including silicone hoses for relaibility) $3000-$4000
4) pre-turbo inlet piping $2000-4000
5) larger Y-pipe (pre TB), larger TB, and post TB Y-divider plenum $2800-3500

#5 takes a lot less labor than #4, but the restricitons pre-turbo are worse than those post-turbo.

For GT30 and larger turbos, it makes sense to go to the Protomotive setup which deletes the airbox, MAF, and lengthy twisted turbo inlet piping. Instead, each turbo gets a nice big (and short) inlet with its own K&N filter and a huge intercooler with integrated DV. Solid piping exits the ICs to a huge Y-pipe with relocated and upgraded MAF.

Protomotive intake. Pre-turbo filter, piping, ICs and DVs:


John D's car with Protomotive piping. Look at all the room now. Note relocated MAF prior to TB:

 

Yup, exactly what I said in the beginning.

 

and I believe you are correct. But I do agree that this mod isn't worth doing unless you already have to go in there for other stuff. This looks like a real pain the in azz to do if you can't bring the motor down.

 

Chris is pretty much correct in his hierarchy. I have 1-4 (midified Evo air intake we to the Proto/Ford MAF and full Proto fuel system w/ S-Car-Go pre-turbo carbon fiber intake and EVO IC's.

#5 would give me a touch more ponies and a touch better spool but I am done modding and just enjoying what I have.

 

Does not requie engine drop, takes two to three hours if you are moving fast. Again a personal choice with experience and IMHO adding another 20HP on top of what you have is worth it.

 

Art, I'd gain 20hp with 75mm IPD plenum from Vivid?

 

PM sent.

 

Todd,

There have been several back to back dynoes of the IPD plenum and none of them have shown 20 hp gains. On NA cars maybe but not on the 996TT.

 

I'm willing to pay the labor to install and dyno just to see. Dan would give me my money back if I was not happy.

 

Not sure you would see much gain under 600whp? Especially if you don't have all big piping and intercoolers too?