The problem is, when you lower the compression and raise the boost, you essentially net similar results. I will explore this option in greater detail and figure out if it is a worthwhile and viable upgrade.

 

Not when your Vortech V2 is generating significantly more CFM's @ 7-or-8psi (than 5psi) to bring you back up to the same effective compression ratio as having 5psi on stock comp. (11.3-to-1). ...definitely look into it, I see you guys breaking records and changing the whole "911 resale market" with ~460+rwhp stage II M96 3.6's ....haha.

 

Todd - the dyno's on your site for the 997 cars with the supercharger are through the stock exhaust correct?

I think what needs to be figured out is how much power is lost by dropping the compression and how much boost it will take to surpass that point on pump gas. If dropping the compression with a head gasket the same way RUF does it allows more boost creating more hp safely on pump gas I don't see a downside to this and I don't see why this wouldn't be possible.

 

Why wouldn't 1 bar be possible? 500 wheel should be achievable theoretically.

 

You can put in as much boost as you want as long as you do not exceed an effective compression ratio of about 17:1 or so. If I was to build one, I would lower static compression to what RUF did (9.7:1) and pump in 11 psi. However, consideration and adjustments have to made to how you can get enough fuel to the cylinders. Even tho your effective compression ratio can be the same, the more air you can compress with the blower before it enters the cylinders, the greater amount of fuel can be added for more power. This is effectively increasing the size of the cylinder. It doesn't matter (as far as fuel mixture goes) how much the static compression ratio is...the amount of fuel you will need is dependant on the amount of air entering the cylinder. Therefore, an engine that has a lower static compression ration but more boost, will deliver more power than an engine with less boost but the same effective compression ratio.

Can the fuel system (pump) handle the increased volume of fuel that will be necessary. Can you turn a Vortech blower fast enough to produce a net boost of 11 psi after plumbing and aftercooler? How will the emission sensors respond? What will be the lifespan of the blower that is turning that fast?

 

theoretically it's possible to go extreme like that....but practically there are A LOT of other factors which need to be rediesigned to make that a reality. Just a FEW that to mind....intercooling & fuel system upgrades. To achieve 500rwhp you have to significantly lower the compression to perhaps (9.3-to-1) or two full points (possibly more) to run the boost needed to make that kinda rwhp (11-12psi). #1) That "may" cause off-boost drivability issues with a "centrifugal style" F/I'ed motor when at low rpms and you have no/little boost. #2) "PSI+" creates heat and you would have to increase your intercoolers abilities/efficiency to compensate for the additonal 6-7PSI of boost/flow over what the stock EVO's system was designed for. #3) Injectors may have to be swapped for larger ones being your making significantly more power than the stock kit. With a complete re-tune by GIAC to go with it. #4) Pulley's may have to be made to accept larger belts due to "possible" belt slippage issues at the higher boost levels your trying to get out of that blower....etc, etc...all can be addressed with a decent amount of R & D however.

...I am not suggesting such an extreme and ambitious target HP however where things become more difficult and NEED to be redesigned. Bumping up the stock EVO system by just 2-3 PSI or so will negate having to do almost all the things I just mentioned but will still give a NICE increase in rwhp that'll take the 996/7 owner to another level/notch UP in speed, cheap.

 

Hahaha....I just read the thread after posting my reply to sticky question/comment and you beat me to the punchline this time...for once our posts mirror each others* ....don't get mushy on me though!

---Kevin

 

I think it makes sense and will work. The problem may become too much boost with the stock head bolts and rods. We have built these motors before and the head bolts will have to be addressed at some power level yet to be determined. The same goes for the rods. We already have new head bolts and rods in development. In theory this all feasible but testing the limits will be another story. I like the idea of 8-9 PSI with lowered compression but if we can upgrade some other components while we are replacing the head gaskets and get more reliable power, then it may become even more attractive for the money spent

 

what kind of HP could you achieve doing this while not blowing up the motor? are we talking 30-40 hp or 90 plus?

unless it's gigantic gains, i can't see it being cost effective. i'm sure there will be some that will do it anyway, but the bang for the buck ratio will be way out there with this setup.

i'm not sure how much parts will cost, but i know labor cost would double or triple over the base kit with a package like this. combine that with the added cost of the rods, headbolts, head gaskets, and other misc stuff to make this work, this is going to get expensive fast.

i'd love to see some people on here undertake this project. it would make for some interesting testing.

 

deputydog95,

That is my point. To spend a large amount of $$ for an additional 30-40 HP seems tough to swallow. Additionally, there are not that many companies in the US that have or will want to purchase the OEM Porsche tools to time the camshafts. This limits the installation to a Porsche dealer or at our facility. I am not sure how many takers there will be. I will gladly do the R&D but there has to be a long term payback for the effort process. We need to make sure that there is enough benefit for it to be attractive. If it were $5K and 100 reliable HP, I am sure it will be worthwhile. But $5K and 40 HP, I am not sure.

 

*$5K for 50RWHP* is definitely worth doing the upgrade Todd. That would take the performance level of the light 996/7 C2 to another level that clients would definitely come out another $5K for... (i know i would)

---Kevin

...there's a BIG difference between a ~420rwhp and a ~470rwhp 996/7**

 

Congrats on getting it into the 11s... Always knew that thing was fast! Actually all the SC'd cars we've done over the past year or so have pulled great and I've just never had the chance to drag race one. I've "threatend" to but this is great and gives folks an idea of what their cars could run. Knowing the weight of the 997 3.6 vs the lighter 996 3.6 SC'd cars I'm very sure a 3.6L SC car would run high 11s also. I'll try to nab one to test...

 

Can TIP handle the upgraded power?

 

Mishref, yeps it can... We did a couple in the past year (996s). It's more complicated in terms of the install but otherwise works.

 

Sharky and/or Todd: How do you think these kits respond to cat bypasses? I know there will be a CEL, but as far as performance, what are your thoughts? It won't foul the ECU up or anything, right? Are there significant gains to be had using the bypasses in conjunction with the SC?