3.2L to 3.5L - Part III (DYNO!!!)
 

Well, it's time to put up or shut up. No more bench racing for me, it's time to see the cold hard truth about what the 3.5L motor actually does.

Fortunately, the planets aligned and I was able to schedule dyno time at Vision Motorsports in Laguna Hills, CA on Wednesday the 29th AND have the added pleasure of Steve Wong coming down (again!) and offering to help further tweak the motor.

To recap, here is the 3.2L that I started with in early September. Baseline dyno figure on Vision's 248C was 199 rwhp with a Steve Wong chip, Dansk pre-muffler and Dansk single-in and dual out stainless muffler:

http://forums.pelicanparts.com/uploa...1104204432.jpg

Here is the now 3.5L that went back in the car in early December:

http://forums.pelicanparts.com/uploa...1104204619.jpg

Here are the build details (the short version):

3.5L displacement using Mahle 100mm pistons & cylinders
Measured 9.5:1 CR
Cylinder heads polished only (not ported)
Twin-ignition using 993 distributor & Andial signal splitter
Engine case boat-tailed and shuffle-pinned
100mm cylinders mooned
ARP head studs
ARP rod bolts
AASCO Performance valve springs
Web-Cam 20/21 camshaft profile
Magnecor KV85 8.5mm custom spark plug wire set
Extrude Honed Intake Plenums
Bored throttle body
1 5/8" European Racing Headers by George equal length headers
Dansk 2-in & 2-out stainless muffler w/ 84mm tips
Custom/optimized Steve Wong chip

The motor will be dyno'd on the exact same dyno it was baselined on and will be as it will run on the street, namely using 91 octane pump gas.

It will be dyno'd again at a later date on a different 248C that is also local to me, just for the sake of comparing the numbers.

My goal is 238 rwhp (which if you ASSUME a 15% drivetrain loss) is 280 flywheel horsepower, which is 80 hp/liter where Porsche's most powerful street motors have traditionally hovered.

I will be pleased if I meet my target, disappointed and will find a way to if I don't, and jump up and down if I am significantly over.

So, without further adieu, WHAT DO YOU THINK THE MOTOR WILL PUT OUT AT THE WHEELS GIVEN THE INFO ABOVE???

WILL I GET THERE?

231 RWHP.

-Andy

certainly "LOOKS" like 280hp! Nice :) Good luck.

I can't answer your question, but the motor sure looks nice. Hope you get the results that you want!

232 RWHP, he, he, he....

229.8 rwhp. You'd be at your goal if the cr didn't come in a little low...

If possible I'd like to come see you dyno and possibly take a ride in your car since I will be in the area on Wednesday. What time is your appointment at?

I think 280 is possible... Good luck Ralph!

247.5

Gonna be close!

What a tease; I saw the thread and couldn't click fast enough on it, then I see we have to wait 'till the 29th. Damn!
J.P.
Ps. Ralph: the clip/bracket that holds the TDC, crank position and cyl. temp. leads is on backwards.

Ralph:
Mine has never been off:
http://forums.pelicanparts.com/uploa...1104211158.jpg
j.p.

No kidding! Now you tell me! Should I tell you guys that I have an extra rod bolt left over?SmileWavy

LOL..in that case...I estimate 29 HP..then stand back! :D

I have a 248 and I have learned not to guess.
But you will be close! Torque should be nice. Press the petal HarD!
Only 1 question.
Why didn't you go with a higher compresion?
With the twin plug setup you could have easlly gone up to 10.5 ot 11 on pump gas.

Good Luck Man!

Ralph:
I saw it when you posted a pic of the engine complete and totally forgot, besides I didn't want to sound like a smart ass.
Regards,
J.P.

BTW:
What happened to this bracket?? That's another 15 hp. :~()

http://forums.pelicanparts.com/uploa...1104213197.jpg

j.p. (smart ass)

Long story, too long to post again. Check out my 3.2L to 3.5L Part II thread for the whole story. Cliff notes version is that the Mahle 100's were advertised at 10.3 but actually measured out at around 9.2. Milled .020" from the heads to get back to 9.5.

No way can you run 10.5-11 CR even with twin-plugs on 91 octane here in California (at least for any length of time). No knock sensors on 3.2L motors to help my ears in case of detonation.

Ralph

Best of luck! Either way nice motor. I bet it is a hoot to drive. Ralph what is your car's weight?

Let's hope you do at least 238 rwhp! I've got 3.2s pulling 226 and 235 at the rear wheels, dynos sheets online here. In Bruce Anderson's book, pgs 150-151, Jerry Woods built a twin plug 3.5 from Carrera 3.2 engine that put out 252.1 hp at the engine, and I think we should better that significantly.

http://forums.pelicanparts.com/uploa...1104215259.gif

Thanks Steve, you are killing me!SmileWavy See you on Wednesday!

Vision's 993 twin-turbo race car just saw 668 at the wheels last week after the installation of ITB's and some MOTEC tuning.:eek: Maybe I should mix-up the dyno sheets???

Ralph

Dane,

Weight is 2,880 lbs. with an absolute FULL tank of gas (i.e. can't get another drop in there). This was done in the summer before the motor came out.

With the new motor, the heavy heat exchangers were ditched in favor of lighter headers and the heater blower assembly and tubing was removed as well. I have the parts in the garage but haven't weighed them yet.

I'm sure someone here knows to the lb. how much less this is.;)

My Carrera is destined to be a civilized street car that my wife can drive on occasion and enjoy. IMO it is too nice to strip down any further. The only other thing that may be removed down the road is the air conditioning if/when it gives up the ghost.

Ralph

280 is certainly possible, particularly with that displacement. What may hold you back are the somewhat mild cams you're running. That engine would scream with RSR pistons, an 'S' cam, and a Tec-3...

Don't bet the farm either on dyno results - they're all relative...

-Wayne

We are talking the conservative dyno at Vision, right? That's why I went low...

Just as important; how much torque will it produce?

Good luck with your lovely engine.

Wayne, it has RSR pistons in it, one they work better for twin-ignition then the CIS/Motronic type and two, just in case I ever decide to take it out of the Carrera and stuff into a pre-76 chassis I would only really need to change the injection and install "S" or GE-60/80 cams. The bottom end is pretty much ready to go.

Motor is designed to pass smog (i.e. mild cams) here in California and the limitations that go along with it. A couple of hours taking the headers off and putting the stock system back on is not that big a deal. A cam and induction swap every 2 years would be a bigger deal (at least for me).

I've always said, if Steve Weiner ever gets CARB exemption in CA (but why would he go through the expense?) for his new ITB set-up with EFI, I am first in line.

Completely realize that dyno results can be taken with a grain of salt, I am really more interested in seeing the percentage gain since the motor was baselined on the same dyno. It's just kind of fun to play the guess the horsepower gain.

I will also be using Primedia Publishing's Dynojet 248C at a later date to compare the numbers that are received tomorrow.

Ralph

off to the dyno, will try and post the results tonight! (good or bad)

Ralph

Good luck Ralph - I'm pulling for you...

Yeah... good luck!!! I can't wait to see the numbers. Must be quite exciting for you after all the work done!

Ralph:
Are you out there? The anticipation is killing me, please hurry!!
J.P.

Yeeeeeeeehaaaaaaaaaaa-can't wait!!

I'm here guys, going to start a new thread.

Let's just say I've got a smile on my face!:D

Stay tuned!

You're killin me where's the new thread??????

No, please, no more waiting, The humanity of it all; how can you you do this? ....and the numbers are???

insert chart here:


J.P.

Ps I wil not free Bertuzzi if you keep me waiting!!!!!!!!!

tease.


link us when its up. I cant wait to see what this beast did.

Can someone give me a hand and link to the other thread? I'm too computer illiterate to figure it out. It's all I can do just to turn the thing on.

Thanks!

http://forums.pelicanparts.com/porsche-911-technical-forum/198971-3-2l-3-5l-dyno-results.html

Thanks Souk, I appreciate it!

Ralph