I currently have a 99 3.4L Cab. And just got my hands on a 3.8L 997 Engine. Whose done the conversion and what am i expecting before i take this on?
Is it better to supercharge the car? ST? or TT? And what's the price difference?
I opted for this route b.c the NA sounds a little more enticing due to stability and reliabitlity on the car..... but im pretty sure there's a number of you out there with the VF and TPC have no problems at all...... but having an NA 3.8L with 360 hp with 300 tq sounds pretty nice..... Please let me know what you guys think......... put a deposist on the 3.8 but NOT completely commited yet.......... maybe a tt or supercharger is the way to go...... Please Advise........!

 

WOW that will be a huge undertaking....good for you!
How much is a motor like that selling for,if I can ask?

As far as the two FI systems.....

Both offer something a little different with power delivery.
A VF supercharger will be quite linear and build boost/power with RPM's...like it is now only on steroids,LOL!
Turbo will hit hard right away and stay there........

TPC are the ones with the latest-greatest and seem to be getting some good feedback so far.
Whichever kit you buy ask the question of how much boost is expected and where they are measuring that boost....compare apples to apples!
Depending where boost is measured,you can get quite a different reading!
Bottom line IS what kind of boost is behind the throttle body!
I am making around 21RWHP/PSI of boost which would be in line with the chargers I know......I actually sold my first charger to Cattman and he HAS the same Gtech netRWHP I did +- 4 netrwhp
a Turbo will have a bit more power because you do not have to turn a belt.

GL and keep us posted....sound like a really interesting project!

Stacy

 

From my little bit of research it's not too easy.

 

We converted a Ruf RTS(virtually a 99 gt3) into a 996 GT2... Was not easy or cost effective.

 

Im fairly new to this board but from what I have seen there does not appear to be many members who have wanted to try the conversion to a newer motor but have instead opted to supercharge or turbo charge.

If you do the conversion document everything you can and take lots of pics and dont be afraid to ask questions....Im sure that depending on the question someone here would be able to provide a good answer or suggestion as to how to over come an problem.

 

I would love to replace my 3.4 in my 01 C4 with a larger engine but I am leaning towards a bi-turbo kit being developed by IMA Motorsport in Northern VA.
Good luck with your choice and please be sure to let everyone know what you decide to do.

 

I would suggest supercharging it instead of replacing it with 997 3.8. Their both not cost effective but the horse power gain is more substantial on supercharging your current engine. Now, the question is, is your 996 engine still good and can last long to make the surpercharging worth? If not, then might as well save the money on buying a brand new "off the crate" 3.4 engine with updated internals.

 

I did a 3.6l to a 3.8l conversion on my 02 c4s. It was fairly easy with the exception of the custom tune I had to get done by fvd, and not cheap.

 

A 3.4 to a 3.8 is much more difficult because of the e gear and a couple of other things involved.... doing more research it seems to be a better deal to just buy another porsche instead..... in regards to supercharging.... tempting but also the turbo kit for the nb..........

 

Any idea what the issues would be to convert a non-egas 3.4 to a 3.8? A member on Rennlist did a 3.4 non-egas to 3.6 conversion and said it was fairly easy. I believe he swapped the throttle body and ran a separate switch (?) for the variocam plus (?).

 

The difference between VarioCam (which is basically an on/off system) and VarioCamPlus really does not allow the use of a simple switch if you want true functionality. Take a look at this post I did awhile ago.

https://www.6speedonline.com/forums/...ks-primer.html

 

I am alway facinated by those who want to build more powere into a car not designed for the added power. There are many things to consider is transmission vulnerability to the added power, the suspension set up with the added power, etc. ANd then there is resale of the automobile... Usually a purist buyer would not touch such a car with a 10 foot pole. If it was me I would just look for a really clean Turbo. You will get designed speed with factory specs and good resale down the line. Sometimes we try to do too much with these cars and in the process we cheapen them.

 

Dharn55.... that's what the Porsche Tech told me in Beverly Hills...... he stated that it was easy to do...... then i did some research and found out that you will have to keep it on all the time..... no ore on.off switch

 

You could do a simple on/off based on the rpm's of the engine. The 3.4 system turns on at 1,500 rpm and off at 5,500 rpm. with some variation based on the temp and oil pressure. But it is on or off. The 3.6 varies both the amount of advance over a certain range and the lift based upon multiple inputs, so while it could be an on/off system it would not be the same. You really need the newer DME.

 

I did the conversion from a 3.4l to a 3.8l on my 03 c4s. There where quiet a few hickups and problems. I wouldn't do it again if I had the option. The power upgrade is nice but not worth the headache I went through.