rval_1999

Someone mentioned that an early model 3.4 liter engine can be moded to be stronger/faster/better than a 3.6 liter. Do tell........ (P.S.- I have the 3.4L 1999MY)

faris13

I might be wrong but I believe what has been said before is that in terms of "chipping" your 996, the 3.4 had more potential for gains than the 3.6 with the chip.

washington dc porsche

All I've seen is the my99 takes better to ECU reflashes than later models years.

rval_1999

Tell me about "chipping" and ECU flashes..... Who makes, how much $$, how much HP, and how noticeable???

washington dc porsche

I got mine through my local dealership but the company is www.evoms.com. The prices are on their web site.

nycebo

In terms of modding, yes it has been written that the 3.4 has more upside than the 3.6, but let's not kid ourselves, the 3.6 is starting with a 20hp head start. I don't think you'll be catching it soon unless you equal it and then count on the fact that the 3.4s weight less.

And of course, my response rests on the 'assumption' that mods add power. I think they do, but I'm not getting into that on yet another thread.

Mitty

Anything to do with cable throttle vs. e-gas?

agio

3.4 potential is greater than the 3.6? hmmm. Do you mean if one adds, say, 30 hp to either, then the % gain on the 3.4 = 10%; while the gain on a 3.6 =.09375%...is this the potential you're referring to? Or, is it something else...?

ElTorrente

One advantage of the 3.4 is that it revs faster. Lower recipricating mass equals real gains - in the same way reducing wheel weight does. Not to mention, of course, that the 3.4 cars weigh 100lbs or more less than the 3.6 cars - this is why magazines tested 0-60 as fast as 4.6 for stock cars (with drop clutch starts of course). The only disadvantage the 3.4 has is lower torque than the 3.6, but really it is a great engine. You get 220ftlbs of torque from around 2600rpms, all the way up to 6800 or so, with a peak of 256 around 4500 I think - this is an excellent, flat torque curve.

Some say that mods don't add any power, but that is simply ridiculous. Sometimes you may see optimistic claims on certain HP figures, but make no mistake that Porsche engines can benefit from some tweaking. It's funny that many people think that Porsches are perfect and can't be improved upon - yes they are incredible engines, but they haven't squeezed every little bit they can out of them- and they aren't perfect.

JimB

I think Grand Am Cup can provide some info here. In that series you have to add 100 lbs to run a 3.6 instead of a 3.4. You are allowed to do whatever you want to the ECU, intake before the throttle body and exhaust. Otherwise the engines are stock. Everyone has switched to the 3.6 so it's pretty clear it's the stronger engine. Even with mods and extra weight.

karlooz

how's it going JimB,

i was wondering if you could post or PM the details of your x51 3.6 conversion or a point of contact. a guy's (from another board) 3.4L engine needs replacement and he wants to do a 3.6L. it's something i want to do when/if my engine goes too. we both have non-egas early '99's

this is a reply from a race shop:
"Wiring is completely different type - cannot be rigged & and a complete wiring harness will not mate up with the rest of the car.
3.4L has a 2 solenoid varicam vs any 2000&up has 4 solenoids. Over 3500rpm the car may not run right or at all!
Dash pod is different.
No easy fix for the e-gas issue, even with programming."

this is a reply:

The e-gas is a simple issue to resolve, the simplest actually. The wiring on non c4 99 model years is a totally different issue. I would only reccommend it for a track only car. The Variocam wiring is a large part of the problem, as well as some of the security systems in the car. Can it be done, simple answer is yes, but there are issues that make it a more than simple swap. But hey, every job is possible it is just a matter of whether or not it is cost effective."

obviously the first race shop is wrong as you have the proof sitting in you engine bay, right?

any help would be appreciated.

JimB

Hey Carlos,
I hope all is well.

What was that line from Monty Python? Run! Run as fast as you can!

I would never suggest converting a non-egas car to a 3.6. With what we spent getting mine to work I would have been way better off buying a donor 2002 and upgrading it. Your mechanic's analysis is pretty good. All the issues can be overcome but you essentially have to build an 02+ car to make it work. Not an inexpensive process. I would buy a used engine for the 99 and trade it in on an 02. You would be money ahead.

Have a good day.
Jim

BBailey

The conversion is EXPENSIVE. Don't kid yourself. It simply cannot be done correctly on a budget. I don't know the exact amount I spent converting my 2001 3.4L Grand-Am CUP 996 to a 2004 3.6L, but it was upwards of $15,000 (don't remember the actual amount, I really try not to look to hard at invoices as it usually gets depressing, it might have been closer to $20,000 actually). Had I to do it over again, I definitely would not have gone that route. Would have been cheaper to sell it and buy an already built and competitive BMW E46 M3 or the new 2005 Mustang FR500C. Oh well, live and learn. Good news is, the car is now very competitive in the series. Bad news is, I'm racing elsewhere next season and no longer need the car.

Gordon Friedman at Autometrics did the swap on my car and did a fantastic job. Yes it was expensive but everything was done right. The car runs great and is much, much stronger than the 3.4L car even with the extra weight the series mandates for the 3.6L cars.

On the topic of the 3.4L engine. I had the PMNA ECU reflash for 100 octane fuel (~$1250 or so). Definitely helped though I would say the benefits would be minimal for a street car as most of the gains (SOTP) were in the upper RPM range, not really usable for a street car but great for a racecar.

Oh, almost forgot to mention, my 996 is for sale if anyone is interested. PM me for details or check the classifieds.

BBailey

Oh, if your friend needs a 3.4L with PMNA tuned ECU, let me know. My old engine is sitting at Autometrics and I'd LOVE to sell it to someone that could get some use out of it.

JimB

Brian,
Where/what are you going to race?
Jim