3.4 upgrade HOW TO pdf - 986 Forum - The Community for Porsche Boxster & Cayman Owners

oliverg · 08-24-2006, 08:19 AM

In my search to learn more about upgrading my 2.5, I found a guy who had updated his 986 to a 3.4 from a 996. He posted a manual on how to perform the procedure (as a pdf)

LINK:

http://www.carltonbale.com/hosted/boxster_3.4_swap.zip

I thought I'd share this with everyone as this guy has obviously taken a lot of effort into doing something that we've all dreamed about.

It took him a weekend to do (staggering!) but he believes if he did it again he could do it in a day.

Some points to note;

- He is using the stock 2.5 exhaust until he has the $$s to upgrade the to custom 996s

- He believes he is getting 300+hp

- He used to have a TPC SC on his 2.5 which he found underpowered at the top end (which lead him to deploying the 3.4!) but he found it reliable and bulletproof.

Enjoy everyone

MNBoxster · 08-24-2006, 11:51 AM

Hi,

Nice contribution. I have saved the .pdf for future reference. Thanks!

Happy Motoring!... Jim'99

Sammy · 08-24-2006, 01:59 PM

And here I thought all I needed was a hole saw and some bigger pistons...

Wow! What a great write up!

oliverg · 08-24-2006, 07:03 PM

I also found this in another section. Sorry I'd saved the text from a thread a while ago so I can't credit it to anyone apart from "Joel Reiser"

QUESTION
----------------

This is a follow-up question to "Boxster 3.4L Upgrade" In this detailed reply from Joel Reiser he mentioned a Resonance Flap and a part from the Home Depot Plumbing Dept. I have a 1 week old 1997 Boxster 3.4L Conversion with a 1999 996 3.4L engine. This engine has a Vacuum driven Resonance Flap.

Resonance Flap:
Joel stated "You also need a 996 ECU, or a Boxster S one, to operate the resonance flap (like VarioRam only not as involved). Without this it will make no power whatsoever, less than before. That feature also requires running a pair of wires from the engine to the ECU"

Q: What pins on the ECU need wires to be added to them?
Q2: Where do these wires go? 12v Vacuum Valve? If so Part Number?

Home Depot Part:
Joel Stated "An air cleaner hose has to be adapted, we've used a Home Depot hose from the plumbing department." MAF to Throttle Body

Q: Can Joel provide a better description of the part? What is it used for in the plumbing Dept, etc. How much it cost approx?
This info might help me locate the part for my project.

ANSWER ---------------------

I can't tell how far along your project is. If it's been up & running for a week, and making more power than it did before, you should be OK. But if you mean the engine is in, and now there are things to hook up before testing, then read on.

After all your hoses and wires are connected and all fluids topped off, idle the car and rev it by hand gently. With the car sitting at idle, you should see the resonance flap switch over at 3120 rpm and switch back at 5120 rpm if the throttle is open by at least 30% momentarily (!) as you rev it by hand. That vacuum device you mentioned will pull its lever to operate the flap when the ECU tells it to. So, yes it is vaccum, but it is also electrical. If it does not operate, you'll be down about 50 or 100 hp. I don't know why it makes such a big difference, maybe the ECU goes into limp mode awaiting a tow truck and a repair. If you don't connect the resonance control line to the right ECU, the entire project is a waste of time.

If you used a 996 or Boxster S intake system you already have the resonance flap and its actuator (solenoid). If you used the Boxster 2.5/2.7 intake system, you have to take it all off and start over. That intake does not have the second cross plenum, nor the resonance flap hardware or tuned chambers. When you finish flipping the 996 intake system around backwards, to get it to fit in the engine bay, the air intake duct from the airbox does not reach the inlet of the motor. Now we're ready to go to Home Depot. Just measure how far you have to go, and your diameter. Go in the plumbing department and look at the big black hoses, there is only one that is even close, and it is almost perfect. I did not record the SKU number the few times we did this, sorry. They can change the SKU number anyway, any day of the week, retail store rules are different from car parts.

The 996 3.4 liter engine vacuum unit for the resonance flap is part #993.110.462.02. Same as is used on the Boxster S, and on the 993 obviously.

You need to run a white wire from its pin 2, to pin 59 on the ECU. You will likely find your wiring harness connector has an empty hole there instead of a pin. So you need a few new pins. It's an Audi part but I don't have the part number.

Yes 12v is a good guess, since the other side of the connection is to the nearest handy source of switched & fused power, red/black on the VarioCam adjusters. Or you can run that back to the ECU as a completed pair, like I do, using pin 54 just because its compatible and its adjacent. Use something sharp to poke a hole in the rubber grommet that passes through the firewall, then plug the hole with your two wires. Use cloth electrical tape to tie your pair in to the harness, and hand yourself $450 for not having to change out the wiring harness.

Joel Reiser /

oliverg · 08-24-2006, 10:04 PM

Quote:

Originally Posted by 98Boxster98

Sorry, Oliver. Not picking on you:

Why would I think you're picking on me? It just seems your on a crusade to make sure the original sources are linked - the content of what you've linked is no different to what's already been posted? I've not tried to take credit for the original posts in any way. Good luck to you - perhaps next time you should initiate a thread yourself?

z12358 · 08-25-2006, 03:56 AM

Just curious...
Are there any limitations that would preclude placing a twin-turbo engine (from the 996 TT) into a Boxster? How much would that cost approx? (No, it's not for my new S, but a 97 Box + TT engine would be a dream track car.)

oliverg · 08-25-2006, 07:50 AM

Quote:

Originally Posted by z12358

Just curious...
Are there any limitations that would preclude placing a twin-turbo engine (from the 996 TT) into a Boxster? How much would that cost approx? (No, it's not for my new S, but a 97 Box + TT engine would be a dream track car.)

I saw a twin turbo Boxster with a 996TT engine in one of the earlier threads so it looks like it is possible. The back of the car was Gembella (had the exahust pipes actually coming out of the body) - apparently was 500+hp, I'll see if I can find the link.

Also - someone managed to do a 3.4l egas into a non egas car - here's the link

http://www.renntech.org/forums/index.php?showtopic=8238

oliverg · 08-25-2006, 07:58 AM

I found the link to the TT Boxster!

http://www.renntech.org/forums/index.php?showtopic=10145

Its somewhere in our forum earlier but I couldn't locate it.

Kind regards

PS I saw a TT engine being sold for 45k $AUD (about 36k $US) on ebay, does that seem a little expensive?

Roughly, how much can a 3.4l 996 engine (suitable for dropping in a 97 boxster) be picked up for?

z12358 · 08-25-2006, 08:46 AM

Thanks for the links oliverg. Looks like the TT Boxster is a 3.2 enlarged to 3.6 with a TT added -- not a 996 TT engine drop. Sounds fabulous nevertheless. They also mention $175k somewhere there which spoils the party quite a bit.

$36k doesn't seem too much for a TT engine, especially if it's relatively new. (But what do I know?) I just figure, if you can get a $16k 97 boxster and spend $10k on labor and extras you can have a TT Boxster Monster for about $60k total which is not bad at all.

Grizzly · 08-25-2006, 09:10 AM

Quote:

Originally Posted by z12358

I just figure, if you can get a $16k 97 boxster and spend $10k on labor and extras you can have a TT Boxster Monster for about $60k total which is not bad at all.

That was sort of my thought process with our '97. When the motor goes up, rather than cry about it, I swap in a 996 engine and still have less than $30,000 in the car...but then Mrs. Grizzly caught me draining the oil out of it. Busted.

oliverg · 08-25-2006, 10:09 AM

I found this twin turbo kit - $6995 for a 2.5!

http://turbowerx.com/page1/page3/page3.html?gclid=CIumy4i3-4YCFSI7GAodCkULIA

Has anyone tried this? I'd love to know what its like.

Kind regards

MNBoxster · 08-26-2006, 09:50 PM

Quote:

Originally Posted by oliverg

I found this twin turbo kit - $6995 for a 2.5!

http://turbowerx.com/page1/page3/page3.html?gclid=CIumy4i3-4YCFSI7GAodCkULIA

Has anyone tried this? I'd love to know what its like.

Kind regards

Hi,

It actually looks to be some fairly nice kit. But, I'm generally averse to Forced Induction and would rather go the 3.4L Naturally Aspirated route instead.

My reasons are two-fold. First, a Turbo complicates things immensely with additional plumbing, electronics, Fuel mapping and HEAT! Secondly, with rare exception, I hate the schizophrenic personalities of a Forced car - one OFF Boost, the other ON Boost...

Happy Motoring!... Jim'99