DrZ1

Would this still be the case w/ a MAF having the airbox out of the way??

Also, I was unclear , wer you saying with a small turbo like 27/6 I would not see much torque increase by going to a 3. 0 from 2.5.

Thanks
Steve

BTW nice Ducati, I sold my 996s a few years back, to pay for up keep on the 951, of course.

evil 944t

Steve, all I'm saying is if you use a 951 manifold, all you do is port match the flange to the head. If you use the 2.7ltr intake, you need to use a new IC pipe. SO, IMHO, I wouldn't do it.

Regarding the turbo, I'm not suggesting any of what you said. All I'm saying is a smaller "XYZ turbo" on "xyz" displacement motor, will decrease lag and improve your low end.

Of course you will see a torque increase by increasing displacement but a quicker spooling turbo is cheaper than a whole motor build..

Re the Duc, Thanks. Its a 748 with an 853 "kit" plus many mods, corse cams, 60mm Ti exhaust, gearing, ecu, Mag wheels, etc.. Its very fun. I will be doing a ton of track days with it this year, I can't wait!

DrZ1

I used to track the Ducati, mostly stock. Untill I picked up a YZF R1 in 04, I actully prefered it. Although I was V. Rossi either.

Steve,

Chris White

So…I have read the thread and there is some decent advice / options mentioned. What I can offer as some general advice is to make a serious effort to define what you want the engine to do for you.
In reality there is not much torque to be had at low rpm / off boost – add more displacement and you get proportionally more torque – but adding 20% to not much gets you not much + 20%!
There are some ways to increase the off boost response / power but it will not compare to on boost performance. What you really want to look at is getting the boost to come on as low as possible and as linear as possible. This will come at the sacrifice of the ultimate high rpm power but it make sense for a street driven and even a DE engine. Ultimate power (to me) is a paper holy grail. I do respect the folks that chase it but getting the highest peak output is not my personal goal.
So – given the stated goals I would keep the 2.5 block / head as the platform and go with the 2.7 stock stroke as the ‘budget’ engine and a 3.0 version (add 3.0 crank) as the higher dollar engine. Of course I am biased towards the MID solution – that will give you the 2.7 base or 3.0 with the stroker combination.
If you are doing this on a budget (and who isn’t?!) I would pick the 2.7 and spend the money saved on the 3.0 crank towards a better turbo and engine management solution.
You can spend more and get more but a well done 2.7 with the right turbo can give you a great street engine – its diminishing returns past that point! (racer territory!)

ehall

Thanks for the input Chris. I presume you got my email?

Chris White

Yep - My Ip is being a pain and bouncing Email today - I will get it to you in a bit!

ehall

no sweat.no rush. My phone # is on the bottom of the email. You can call me if you want. I'll be home about 7:30 EST

PeterK

Chris,

I have a 2.7 engine which I was planning on swapping for a Turbo engine. My main reason was because of the lack of affordable aftermarket pistons. Do you know of any options for 104mm?

David Floyd

I have several years and 55k miles on my 106mm bore, around town torque off boost, is like Chris said only going to be slightly more than a 2.5, just not much going to happen till you get above 3000 rpm.

Above 3000 rpm the power rolls on smoother than a 2.5 with my bore, turbo, engine management package, kinda like back in the day of 2 strokes, CR125 type powerband vs CR250.

Reliability, after the bugs were worked out the engine as been great, till..... just recently a head gasket leak has developed, AFR has been near perfect, so could this be cylinder creap or steam pocket ???? we will find out.

Just don't expect any huge gains over a well built 2.5, I have often wondered did I make the right choice, should I have stayed 2.5 or gone 3.0 or (gasp) done the V8 thing.. yes It has crossed my mind

Compile all the advice add in your budget (which you are almost certain to exceed) your intended use and only you can make the call.

Oh.. my car is fast, did not want to give the impression it was not, you just kind of get use to it, then a buddy hops in and gets all pale, I'm thinking what wrong with you ?

333pg333

No substitute for cubes + TURBO!!!!

ehall

Thanks David. I was going to pm you tomorrow. lol
This time it wasn't because I screwed up an eye ball though!

special tool

The development of power "roll on" is strictly a function of turbocharger configuration.

Believe me, I could build you a 3 liter that would explode your axles at 5,000 RPM.

evil 944t

VERY true, well, not the axle part...

944CS

Why not go with a low boost, high compression motor. Mahle makes the pistons for this. All you have to change is pistons, and rods if you choose. I gaurantee you'll have a torqier motor with a 10:1 turbo 2.5 rather than an 8:1 2.8. Bigger Turbo but low boost to keep the intake air cool.

ehall

Uhhh...I'll passs, but thanks for the offer.