In a recent Excellence Magazine tech question, owner asked about the negative effects of ethanol in his Porsche.

The reply was, in Germany, it's pretty much the norm & the cars are tuned accordingly to perform their best w/ethanol.

Leaded gas was a big no-no......

 

Just make sure it's unleaded and not plane fuel like you said!

I'd look for Sonoco. Like on the pic I sent you.

 

Thanks, searched out looks like there are a few sources local to me. I'll try to get over and get 5 gal and see what happens..

 

Keep us posted!

 

I know this is a 991 forum, but all this talk got me worked up. I took advantage of the Suncoast plenum sale, minutes before the sale ended at midnight. I'm stoked. Apparently the plenum is much more accessible on the 997 than on the 991. I had a hard time reconciling the 4-5 hour installation time estimate, but there's a lot more digging to do on the 991s.

 

Awesome. Keep us posted!

The plenum should have the same performance on either the 997 or 991

 

On the 991 you have to remove the rear bumper cover, you didn't have to do that on the previous 997.1 or .2 to install the IPD.

Dave

 

Thanks, I looked in the engine bay, and it actually looks like an easy DIY on a 997.1.

 

Not correct. The OEM 997.1 plenum is much less efficient than the .2 and 991. For the 997.2, Porsche made it more similar to the IPD plenum. I'm sure that helped with the 30 hp increase between the two.

 

That's an interesting point. I hadn't realized it, but there must have been some intake plumbing differences when Porsche went to DFI. I'm feeling better still about getting the plenum! Thanks to you and my other 991 cousins.

 

Steve O -- where have you been??

What do you think about the IPD for the 991? Know anything about it and any benefit form it? Any downside?

 

With the exception of the 997.1, the newer cars won't benefit as much. You also have to think in terms of the overall shift of the power curve versus max hp gain. Max gain is meaningless as it's a single point of the curve. You want more power across the entire curve, and better mid range throttle response. Many of the IPD kits include the larger 997 GT3 throttle body (TB). The combo would be very noticeable. If you're just switching out plenums (less 997.1), you may not notice much, although it will flatten the curve which is good. In my cars the plenum and TB will make huge differences as Porsche tapers the intake from the stock airbox to mate to a smaller TB. The GT3 TB and airbox exit port are the same size. Porsche purposefully underpowered the 987 using this smaller TB trick. Luckily IPD makes it reversible. Ultimately a more efficient plenum needs more fuel to take full advantage. The ecu will compensate, but with a stock TB it can only do so much.

 

Soooo..... Trying to follow you.

If you had a 991S would you make any upgrades? Nothing exhaust wise.

Any opinion on the GIAC software tune? Familiar with it?

Not really looking to open a can of worms with risky mods. If anything is a sure thing and causes no risk of problems I might consider.

 

The best mod is a better set of tires!! That and PCCB which I'll never again buy a Porsche without!!!

Ultimately I'm all modded out in my life. I don't think mods ever amount to as much as you hope, and it's usually lots of money for little return. Porsche has done an outstanding job to keep increasing the performance level with each evolutionary step. Why mess with the balance they've achieved? If you want more power, you bought the wrong car. Buy the power you want. Notice I didn't say buy the power you need. No one needs more power than these cars offer. I've always believed more power makes for lazy drivers. As an alternative if you want more power, spend more time at the redline.

My biggest complaint with the 991 is that you have a limited tire selection. There aren't any extreme performance options like the Bridgestone RE-11. You're stuck with Michelin or Pirelli max performance tires, or Pirelli and Continental track tires which won't last long with a 80 UTQG rating.

Cheers!!

 

I did a software tune with a sponsor and only noticed a spark knock. No extra power. And my wallet was $800 lighter. I wouldn't waste my money again.