What to build- 3.6 N/A or 3.6 TURBO
 

I have been thinking about this for too long and I still can not come to a decision on this matter.

I have been thinking of 2 options.

#1 N/A 993 3.6
1-STB set up (INTAKE)
2-aggresive cams (7500-7800 RPM- Red line)
3-after market EMG
4-aggresive exhaust
5-upgraded -ROD BOLTS
6- NO POWER STEERING

With this set up I would hope to expect at least 325-350HP

#2 Turbo- N/A donner 993 3.6
1- single turbo
2-JE lower comp pistons- 8.5ratio maybe 9.
3- aggresive cams (6900-7500RPM-red line)
3-after market EMG
4- upgraded rod bolts
5-NO power steering

Expected power 380-425HP . I will not be getting crazy with BOOST.


What set up would be the most rewarding??? Stronger turbo VS weaker N/A.

For some reason I am favoring the weaker N/A set up just because throttle responce + sound will ( I think) be so much better on the N/A set up also I would not have a heavy turbo hanging out back.

Then I think of the power a well set up turbo has available and the money I would save on the N/A STB set up .

MY brother and I will be building the turbo set up + the help from fellow pelican's so I will not be paying a shop for any work .

I would really apreciate any opinion's on the N/A VS TURBO

A redline that high on a 3.6? Isn't that asking for trouble? I'd build the turbo; I think the motor would live longer.

Really..... I would like to think that 7500RPM red line would be on the cautious side, maybe 7800RPM is pushing it, but 7500RPM... I will be very surprised.
I mean its really only 600RPM more than stock.

I am really after the most electric driving experience possible. I know that a turbo will be faster but I just feel that some of that edgy character of a N/A would be lost with a turbo.

I wish I had more experience with these 2 styles of cars.

Herman, turbo will definitely give you that electric feeling. You can machine down the stock mahle pistons(per henry@supertec) for the cr you want and save the JE money. With the increased displacement, CR and efi you will definitely achieve better drivability than a cis 3.3 that you've heard about/or perhaps driven that you feel isn't edgy. A quick spooling turbo will also help since all out power is not your goal. Turbo=ELECTRIC....but then again I'm a bit biased;)

I am biased also. Go turbo. Every car I have has a turbo. I have had a turbo on at least one car I have owned since 77 save a couple sad years in the mid 80's.

So why don't you try to go for a ride in comparable cars and see which one floats your boat. Or you could just do the right thing and go TURBO:D

Hi:

You've gotten some great advice, especially from Dean,...:)

Get a ride in both kinds of cars and make the decision based on that experience and your preferences.

I happen to prefer N/A engines with really sharp, crisp throttle response that have a lot of snap. For twisty kinds of roads, its hard to beat a 3.6-3.8 with ITB's, the proper cams, and a good Engine Management system. Combined with close-ratio gears, its really neat,...:) :) :)

Your choice dependes on what you want to do with the car, what your driving habbits are, and what exhaust sounds "do it" for you.

For example, if this is a steet car that will be driven often and taken on short trips you probably don't want a high strung N/A engine.
If the result desired is a dual-purpose street/track car that you wish to hit the back roads with and frighten children and small animals then by all means do the chainsaw N/A motor.
The difference is not so much power but how it is applied. The turbo is stealth power. You can have a quiet exhaust and a smooth idle with the same HP as a well built high-strung N/A motor.

I would opt for turbo.

First of all, highly strung N/A engine will need to spin fast, and spinning fast will wear the engine more. Also, 3.6 is a perfect base engine for turbo-conversion as it already have twin plugs and everything else.

With well-matched turbo you'll make 500+ hp w/o revving to high heavens. You will also accellerate away from even the most extreme N/A 3.6 you could possibly make (using cubic dollars).

Even if it sounds weird, turbo converted 3.6 is most bang for buck you could get, horsepower-wise. Use JE or even OEM 3.6 turbo pistons.

Swept area under power curve is what accellerates the car and turbocharged engine will accellerate faster than N/A of similar power thanx to much meatier torque down low. N/A 3.6 spinning at 7500 RPM will have lifetime of a butterfly, will cost a fortune to build and will be beaten by warmed-over 3.3 with slightly raised boost. Yes, there is a difference in engine responce but I personally wouldn't pay a premium and loose so much power just to have good throttle response.

So yes, go turbo.

I would get the turbo set up. Why such a high CR? Yet, your first option also results in a proven performer on the track.

Regards,

Thanks for the info guy's.

I will say that I am far from commiting to N/A or TURBO yet. I did enjoy reading everyone's case for builing a TURBO. ( Goran, Dean, Rarly I am not the least surprised heh, heh.)

I guess what I keep coming back to as a comparison is the 996 GT3 VS 996 GT2. Almost everytime it seems that the N/A GT3 gets the "nod" for the most rewarding drive even though it is underpowered and might get passed on the straights. This is what fuel's my indecison.

I am really surprised that a 3.6 would have the " lifetime of a butterfly" (Goran heh,heh funny but sad I guess). So if 7500RPM is pushing it, would 7200RPM be a happy medium??

Goran- You pointed out that if I was to go with a turbo you mentioned
JE pistons or OEM 993 turbo pistons. Would lowering the CR on my stock
pistons like Mike Mentioned ( Henry@supertec)????

If I recall IF2 had piston problem's with the N/A pistons it first ran... right?? Also what CR would you run to minimize lag??? I am thinking 8.5 or 9 to minimize lag but I know this will limit the Boost I can run.
I will be running a aftermarket EMG
I have many, many questions.


If anybody has any opinion's or experience with tuned N/A VS TURBO
please let me know.

IF2 still uses OEM 993TT pistons. It was dynoed to tripple the power you'll ever extract from N/A 3.6. It never ever had problems with pistons itself but motor was cammed to produce peak power @ 7500 RPM. As OEM 993TT pistons are quite heavy, OEM rod bolts took a beating at those revs and had to be replaced due to wear. It never used OEM N/A pistons.

For moderate power (<500hp) you could use 993TT pistons all day long as long as you don't rev beyond 6500 RPM. With matched turbos, you can make a killer motor for moderate $$$ input and drive it for a long time w/o costly rebuilds.

Or you can go the N/A route, buy unobtanium ITB's, headers, rods and pistons, rebuild it every year and still get spanked by some bloke reving 5500 and boosting 1 bar. You can always listen to the noise but noise doesn't propel the thing, it just makes your ears ring ;)

Herman, I am not as biased to turbo power as you might think.

Re-read my post above. Truely, you must think of how YOU wish to drive the car. Some folks can handle a chainsaw motor all of the time - that is their personality. I'm too old for that now. I still like power but for the long haul my butt wants a nice idling car with an exhaust note that won't have the neighbors throwing rocks at me.

Here is what I had before the turbo. This baby ROCKED! Sounded like a mad banshee and carved up roads like a go cart. I miss that car soooooo much.

http://forums.pelicanparts.com/uploa...1148010137.jpg

I like non-turbo cars personally, but I also like the thin-boddied early 911s too. It's really a matter of preference, although a non-turbo will undoubtedly be less expensive...

-Wayne

I don't think a 7.500 rpm N/A engine will be less expensive than a moderate boosted turbo engine...
I am building one and we are changing rods, valves, lifters, retainers etc. to obtain a decent longevity from the engine.

So I went the N/A route. I didn't need/want 500hp on a 2,500lbs car. Like Steve said above the N/A engine will have a fantastic throttle response and it will sing to you.

The big advantage of the turbo will be the torque avaliable at very low rpms (compared to the highly strung N/A engine you have in mind).

If I were driving mostly on the highway, if this was going to be my commuter car and I wanted a less "tiring" car to drive I'd go for the turbo.

Plus I think the turbo would be much cheaper to build. As you said just lower the compression ratio, get a good EMS and you are done.

Having said that would you rather drive a 73RS, or a 930? A 964 RS/993 RS or a 993TT, a 996GT3 or a 996TT.
I realize in those cars is not just the engine that is different but the whole philosophy... but you can easily tell which power delivery you like better... I guess it could be difficult to test drive a 73RS... but u can easily compare 996TT to GT3.

Do it, and focus on just the power delivery, throttle response etc.
The 996TT will exhilarate you on coming out of a turn, when in 2nd gear at 2,300rpm you press the right foot.... BAM!
The GT3 will give you pleasure at the other end of the spectrum.
This is why Steve W mentioned the close gear ratios... U want to come out of the same turn at 3,400...

Keep us posted though! Good luck!

Depends - some like reds, others blondes...

I disagree with everyone - no 911 engine is cheap!

However, we build a 3.8 7500rpm engine with ITBs and all the goodies and it runs and sounds like nothing on earth. It will pull from 2500rpm like a train and the sound is goose bum stuff. The response is awesome, intake sound is awesome...

You get the picture.

Now I'm building a 3.0 non-silenced twin turbo race engine. It is also not cheap! We're using smallish turbos and a battleship sized intercooler - so I hope for a realistic 450bhp. I think a turbo can sound awesome, the whistling, the blowing, the fire spitting exhaust, etc...

You get the picture again.

I'll never part with my N/A and I look forward to my new blown experience. Kind of having your cake and eating it.

Evolution is part of the fun. Start N/A and evolve.

A couple thoughts.
1. I'm wondering what car this is going into, and what trans you hope to use. Turbo motor = no 915, which can lead to a slippery slope, or a different, heavier car.
2. A "wild" cam on the 3.6 motor will be limited by the valve relief. So if you use the stock pistons you're either stuck with 993 cup/ GT2 cams, or you do different pistons (not sure about the practicality of piston mods). If you don't do the pistons it makes the engine management and ITBs a bit of a waste. If you do pistons, might make a 3.8/3.9 more attractive.
3. Data point for the N/A motor- my just dynoed motor is similar to what you're talking. 7500 rpm redline, cup cams, Vram, RS valves, lightweight retainers, custom burned chips for both 91 and 100 octane. Makes a bit over 320 hp on pump gas, and about 330 hp on 100 octane.

I went the high revving NA route for the reasons you listed. After owning a bunch of fast NA and turbo cars I find I like the NA significantly better if it's "fast enough". In this case I decided 330 hp and 2000 lbs is fast enough, at least for now.

I would go with the 3.6 turbo route hands down. You can easily make 600+hp with a basic long block

Longblock, no. But everything else required makes it an expensive proposition...

-Wayne

You are telling me!! I just added up my cost to date on my 7500rpm 3.4 with ITB's and programmable ECU....... OMG!!!! Wish I did not own a calculator!!!!!!!!

But then again, I prefer the feel of sharp throttle response over the big turbo rush, makes the car more drivable on the track with my moderate skills.

Cheers

Here is my data point

My fairly stock 3.0L 930 with EFI puts out 350 RWHP on a DynoDynamic dyno. That was at 13 lbs of boost. Those ain't no DynoJet #'s. I have now turned the boost up to 18 or so.

So I think if you want to make power go turbo and if you want to make noise go N/ASmileWavy Sorry I couldn't resist:p