I've been doing the research and planning for a turbo conversion on my 968. I know many people on here have done 3L turbos, in many different ways, so I was hoping for speculation as well as experience. I'm looking for something that sounds NOT obnoxious or ricey, obviously. Right now I've got the standard 968 engine with variocam, with a cone filter and stock exhaust & resonator. The engine sounds great, but once I hit that torque peak around 4300rpm (the resonant intake "kicks in") it sounds fantastic. It sounds like muscle... like a growl. On the other hand I've heard tons of 2.5 8v turbos and even with any size exhaust I don't like the way they sound. I don't know if the sound is more dependent on valves or displacement. Maybe I can find a 944S and compare it to my 944 to get an idea.

Without getting into too much detail, I'm going to do this conversion the shortcut way, whether I go 8v or 16v. This is my DD. I won't change the pistons or the computer. I might change the rods down the line but only if I start making lots of power. The comp will be lowered with a thick HG and probably nothing else. Front mounted intercooler too.

 

Well if you're going mostly stock components I'd search under Markus' thread. Not sure on the exhaust note though, maybe ask him?

 

Hey

Everything depends how far you want to go with it.. I think you could even use stock 968 exhaust but If id have to do a budget project witch have around 330hp 550nm torque this how I would do it.

Stock 968 engine
Cometic head-gasket (3.2mm like I had)
951 injectors
951 flywheel 930 pressure plate, 968 clutch disck
951 rpm sensors
3bar FPR

951 crossover pipe welded to 968 exhaust manifold + 3" downpipe from lindsey + custom middle pipe to make it work with stock 968 exhaust. IT will be nice and quiet. And i think it should be good for moddest 1.2-1.4 bar boost and 320 whp..

951 engine mount (what holds the turbo) + the oli return from turbo to oil-pan. Balance chaft cover can be modified by drilling the hole into it


951 K26-8 or depending on the budget K27-8 turbo
Tial 40mm wastegate with manual boost control


951 motronic KLR-DME + airflowmeter+ 951 TB + sensor(dont know it thats needed) + custom chip for your application.


951 intercooler with modified end tank on the cooler feeding side (for flow reason) + custom piping and diverter valve instead of BOV because you are going to run MAF not map sensor..

Custom intake manifold or mix-mach from 951 and 968 manifold by using the 968 flange and 951 intake design (look www.944968.com)

If you can then change conrods to 951 RARST CON.rods as a safety, extra insurance

I think depending on the turbo if K26-8 is good for 304 whp (acc lindsey site) then its fore sure good more then that in 16v application. I am quessing + 20-30 whp and huge amount of torque.

If you need to control variocam then i think you can purchase standalone variocam controller from vitesse.

Markus

 

See, I told you he'd know...heheha.

 

the sound of the engine has a lot to do with comp ratio i believe also I'm sure your 968 the inlet manifold itself makes a lot of noise when you really get up it . the turbo pumping air in will I imagine kind of kill the magic induction music will just a air rush sound .
I think you will get the best sound from this set up extend the secondary pipes into a big box type cat or resonator as my friend did it sounded great then just put blower on it

 

Don’t forget the rotary muffler….it has a big effect on the engine sound.
The wastegate also adds its own sound (one that I don’t really care for! – sort of like a constricted shop vac!).
So don’t look for the 968 sound (which I like also!) to carry over to a turboed 16v.

 

Turboed 16v 968 engine on 944 body would sound something like this with 3" catback exhaust!

http://www.youtube.com/watch?v=i2C3pcfBT9E

http://www.youtube.com/watch?v=oZd4B...eature=related

One more

http://www.youtube.com/watch?v=H2gWa...eature=related

Lets not forget about Zorans awsome 16v turbo

http://www.rescueforce.com.au/images/expose-car.avi

http://www.rescueforce.com.au/images/race-pi.wmv


Lets not forget about ballbearing vs journalbearing turbos wich sound also different. Turbo cars make many differnet noises : wastegate, BOV, turbo on spool, surge noise (chattering) etc..

Stock NA sound
http://www.youtube.com/watch?v=YcnZilPm2bY

 

Although higher compression does give a raspy effect to the exhaust, the shape of the intake/exhaust manifolds is mostly responsible for the sound you hear, much like an organ (or any percussion instrument for that matter).

That, paired with the exhaust pulses dictate the familiar noise you hear (4, 6, 8 ,10, 12 cylinder engines each make distinctive sounds; inline or V shaped)

The intake manifold on the 968 and 951 are shaped very differently, and that explains why they sound so unalike.

 

I love Zorans car but i stood behind it at a dyno comp and it didn't sound that great until he would lift off and the fireballs would would explode out the back .. I remeber it had 300hp@3.2k and somthing like 480 at 7k not sure but it did have a wide power band.

 

Thanks everyone for the input. I'm sad to hear that if I go turbo I won't have anything that sounds like it does now. Sound is one of the most important things to me!

Markus, my budget is about $3500. I'm going to do all the work myself. What I'm looking for is a nice upgrade in power from 236, so 300 would be good... 330 would be great! I'm not sure if at 330 I'd need 951 rods. I have 2 968s... if I turbo the car with 220k miles I will definitely do the rods, if I do the 170k miles car, I might keep the stock rods for a while. I will keep the motronic and use a custom chip. I'm still deciding on the 951 flywheel - I know it's much lighter but I like the 968 2-piece bellhousing.

Chris, most of my current engine note is coming from the intake. My mom's 968 is all stock and mine only has a cone filter, and the sound difference is astounding. I was going to do the exhaust to get the engine music of my dreams but then I decided to go turbo so it was pointless to do exhaust work until then.

OK, so turbo will just change the overall sound of the car. Then the new question is: Does 8v 3.0L sound better, or 16v 3.0L? By better, I mean more growly, muscular, etc.

 

What about supercharger? $3500 seems kinda skinny to me, but I guess if you can do everything yourself.
If you are only going for a moderate increase in power you may be able to stick to the same c/r or just a little less which would help with the note.

 

yeh no one can spend money like you Pat except my handbrake she has a pair of black pointy shoes for each day of the week

 

Hey you would need 951 flywheel ony when you are changing the whole ignition system to 951. RPM reading is different in 968 vs 951. If you can write custom chip thats fine and you can keep stock 968 DME.

If your car is 93 06 and up then most likely you have same con.rods and same pistons as my car did. My engine has done 6000 km after turbocharging and still pulls strong.. My car dynod 570 hp @ flywheel.. and I have 951 rods..

For 3500 I quess you can buy mentioned 951 parts and do the work yourself.. IF you cannot get 951 rods. the S2 rods are beefier then 968 ones and worked well in my engine when I dynod 402 hp in 2005..

Markus

 

Markus, I can't remember what your c/r is?
Adam, You betcha sweet Bipee!! That's showing my age...

 

Its 9,5:1 I am running 1.4 bar with pump fuel stock cams.. full boost wtih GT35BB 0,82 @3200 rpm.. in 4th WOT