993 TO 993TT ENGINE DIFFERENCES??
 

I searched...

I want to know what differences there are in the 993 to 993 internal differences?

Block, crank, rods, cams, heads, etc.

All they all the same long block except for higher compression? Do they have different blocks or heads?? Anyone know all the differences?

Rods and crank are the same. Heads, pistons, and cylinders on the 993tt are different. 993tt pistons protrude into the combustion chamber to reduce stress on cylinders during combustion, the cylinders are shorter, pistons have a flatter top for lower compression and the heads are single plug with different size valves than the twin plug 993. Maybe someone else (like Steve W.) will chime in with more detail.

:cheers:
Jay

The rods are reinforced as well.

So it is possible with a rod and piston change to essentially be able to throw twins on it and have a tt car with a motor that will last.

why not just buy a tt to begin with?

you would also want to add the forged cylinders.

i imagine the cost would be more than buying a TT. Also I really doubt resale would come close to equalling a TT.

Agree with above. If you just want to go down the bolt on path, starting with a TT or trading in a NA car to get a TT would be far wiser. If you want to build something unique then start with whatever base you wish.

Nope, bottom end is the same except for a few studs.

p/c are different as are heads(single plug on tt), valves, guides, cams, carriers etc. all different

Now why wouldn't you want to use twin plug heads on a turbo? The extra plug would let you run an extra point of compression for better response, or more boost. Is there some critical weakness in the twin plug heads that make them unsuitable for the TT?

Protomotive has been (low-boost) turbocharging the stock 964 and 993 engine for a long time without problems (i think for around $8k).

I do not have first hand knowledge.

I am quoting Motor Trend:
"The Turbo's powerplant is basically the same as the powerplant used in the Carrera, only with lower compression, reinforced connecting rods, and upgraded engine cooling systems"

And Road & Track:
"The engine itself receives special tweaks to live under the maximum 11.6 psi of boost; Compression ratio is lowered to 8.0:1; and connecting rods, piston crowns and cylinder heads are reinforced"

It is quite possible the magazines were given the wrong information at the time and just quoted the spec sheets they were given.

Bill Verburg is giving the correct answer.

To get the complete list just look in the PET engine section for the turbo engine type designation M64.60 on the far right column next to the part description.

Rods and crank are identical. Same part#'s too.

Extensive machine work will be required for it to be identical to a TT engine. A good machine shop can do pretty much anything I guess but it's not worth it IMHO, better to just buy a TT engine.

Except for sourcing some stock TT pistons and upgrading to billet rods, and tuning, I can make a twin turbo setup for about $5k. I will also have to research if I want either obdII and have it tuned, or jsut go to a standalone.
The TT cars all about $30k more then a non turbo. Plus I don't know if the AWD would handle 600+ whp.

Oh Oh.....

600 + Hp? You will NEED 4wd. - depends on what you are using the car for I 'spose....

As for being just $5K - an exhaust, cats and pipes (good ones anyway - and you will NEED good ones if you are aiming for anything cliose to 600 + Hp) will run more than half of that......

If you are serious - you need to be on the TT forum.....the truth will come out over there....

BOL

Simon

EDIT - I see you asked the same Q's over there - didnt you like the answers?

You do realize that you will need the 993tt pistons and cylinders. Those alone are around $4500 last time I checked...

But hey, if you can do it all for that much I say go for it.

To all that replied to my comment, thank you for the correction. I do find it interesting that both Motor Trend and Road and Track reported this fact incorrectly. I also would like to say WOW, how awesome is it that the internals are stout enough to put this kind of power through? Most cars I have worked on will hardly deal with a 50% increase in power, and certainly not in the reliable fashion Porsche would expect. Just goes to show how stout these motors are even in their basic form.

NVR

Im currently in process of replacing my entire motor of my big bird (c4s) with a 3.8tt (twin plug) with 750whp (pump gas) and way over 800 (race gas) and with AWD. it does cost a lot. more than how much I bought my car for including labor.

I should have added that I am a fabricator, the headers, intercooler, exhaust, etc, I will just whip together myself. That is why I can do this so darn cheap, I have done it before for that price on another car, 800 rwhp on 93 octane.
The part I am researching is the motor end of things. Some mention jugs, besides being cast, is there any difference? What is the hardest anyone has pushed the cast ones? Pistons are cheap($800), so are rods($1800). Stock cams will be fine at only 500-600 rwhp.

I also have to find out how far I can push speed density... I may just buy a Bigstuff3.

Well, time to keep researching... Thanks for the input, really helps!!

That certainly does change things! I was wondering how you were planning on doing this without spending a small fortune. I do know there are some people running what I believe is a roots style, superchager, on there stock block 911's. I am not sure what kind of RWHP they are putting out, but you could get a durability report from them, as far as the cast cylinders go.