3.0-Rebuild Experts: What HP is your guess?

[Gunter]

What numbers can I expect with this SS 3.2 I just finished:

Bottom is from an ’82, mild boat-tailing, standard 70.4mm crank.
CIS is from a ’78 with the larger intake runners.
Heads are ported to 39mm.
98mm P/C’s, 9.8:1 CR, CIS dome.
Cams are 964.
SSI’s with an M&K muffler.
I am keeping CIS and Bosch CDI.

Please, no suggestions on what to do to get more performance, i.e. carbs, MSD, EFI..........just some numbers on the above.

What’s your guess? HP? Torque?

I have to add that there is no dyno for me within 200 miles.

Thanks.

[Drago]

You know, carbs make more power.

[boxermania]

I have seen dyno runs for similar set-ups and I would guess around 220 hp at the rear wheels (260 at the crank). However, with a minor investment on your part, the weight of the car and driver and a g-meter you can figure the HP very easily. Someone in this forum my even have a G-meter to loan you or rent......they are fairly inexpensive.

Let me know what you get for a result, I also have a 3.0 l

[Gunter]

G-meter? What's that?
What does NOS stand for?

[boxermania]

G-meter is an accelerometer that you mount on your car and will compute HP based on a time and distance run. It's the poor man's dyno

NOS, means new old stock and usually refers to replacement parts

[LvSteveH]

229 hp / 209 tq @ FW

[Facey]

210-220 hp@ the wheels

sounds like a very nice engine, sure it'll be fun

[Carrera3.5L]

Some of you guys are dreaming or use a very optimistic dyno...

A stock 3.2L Carrera motor makes in the mid-180's on a Dynojet and one that has been SW chipped with exhaust makes 200-205 whp all day long on a Dynojet, how would this motor make any more with CIS and pump gas?

A more accurate picture would have been a before and after on the same dyno, which would show you your improvements (which is more important than peak numbers).

For a guesstimate, 200 whp on a Dynojet 248C... The power improvement will still be noticeable and make the car more fun to drive...

Ralph

[Gunter]

Ralph:
Read the details on the above SS 3.2 and try again.
This is not a Carrera 3.2 engine.
SC 3.0 for US is listed as 180 HP with a 175 ft-lb torque at 4200 RPM.
Just using SSI's with a Flow-thru muffler on a stock 3.0 liter will give an extra 15 horses.
Add 98mm P/C's and 964 cams........................
Why is 220 HP optimistic?

[Steve W]

Ralph quotes rear wheel hp on a Dynojet at 200, dividing by 0.85 is 235 hp at the engine, so I don't think he's lowballing your engine. My estimate on street gas, in an optimal state of tune with fuel and ignition is about 205 rwhp, to a max of 210 at the wheels on a Dynojet.

[Gunter]

Sounds good Steve.
So, the 180 HP for an SC quoted in the Red Book is at the engine?
How many different ways are there?
Engine HP
Wheel HP
Brake HP
What more?

[AntiCHP]

I tend to think 220 whp is within reason.

My 3.0 was a small-port (1980 USA) motor but I added a Euro fuel dist., & injectors with a throttle body opened up by EBS Racing, with SSIs, etc. and it produced 201whp @ 6250rpm & 188lb/ft @ 5000rpm on a Mustang dyno.

The extra displacement, 964 cams & larger ports will surely put some extra beans in the can!

-And it ought to wind-up nice with as a short-stroke!

What's 200 miles? You really should get it on the dyno... after all, now we're are curious to see how it turns out!

Good luck!

[sammyg2]

208 fwhp.

[rlh930]

My guess would be 220 at the crank, 190 at the rear wheels, and 260 at the Web site.

[Carrera3.5L]

Originally posted by Gunter
Sounds good Steve.
So, the 180 HP for an SC quoted in the Red Book is at the engine?
How many different ways are there?
Engine HP
Wheel HP
Brake HP
What more?

It seems apparent that you are unsure of different methods of measuring horsepower/torque. Here's some more info for you to ponder...how about PS, DIN, SAE, Kw just for starters...all will give you different numbers with the same engine and we're not even getting started with the type of dyno being used and their variations...

My guess still stands if using a Dynojet (even though I apparently don't know the difference between a Carrera 3.2L & 3.2L SC based motor...

Ralph

[Steve Marshall]

My 3.0 liter euro motor dyno'd 210HP at the rear wheels. The configuration is the same as you have stated except for the cams and displacement.

[rdane]

Fun part is no matter how you measure HP then you have to correct it. Your numbers will vary depending on where and how you measure it obviously.

Most common numbers thrown about locally will be from a Dynojet 224 measured at the wheels. You cna look at corrected and uncorrected numbers. Add 15% for drive train loss if you are feeling frisky and need a ego boost for your labors, and a number to compare to Porsche's BHP. Most 911s will be clsoe to the stated BHP#s when measured at the wheels. I heard they raise bigger horses in Germany You should be right between these numbers from a CIS 3.4 and a 3.0. Although the 3.4 hit 223 hp and 216 torque once it ran in a 5000 miles.

So my guess is 200hp and 190# of torque. Add the 15% for 230hp and 218# Torque at the crank. Although most 3.2 conversions I have seen posted here have been in the 190hp/torque range at the wheels.
At one point I had recorded the dyno info from several dozen 3.0/3.2/3.4/3.5s. But this should give you an idea.




Here is one of the Pelican 98mm 3.2 rebuilds from Pelican and a couple of 3.0 liters ...a search will find you others.

Originally posted by emcon5
Just got back from the dyno:




Three runs, essentially the same results each time. I expected more power, but I realize that dyno numbers are a little subjective. On this dyno, on this day, my car made 174HP at the wheels, call it ~205 at the crank.

Frankly, I care less about the power output as I do about the AFR. With 98mm bore and 964 cams I was a little concerned about the stock CIS being able to deliver enough fuel, but ~12.2:1 at 6500RPM is not lean at all, it is a little rich.

I am a little concerned at the RPM figures, I shut down at 6.5K on the tach each run, but their graph shows almost 6800. Looks like my tach may be off.

The dyno place was ATP Turbo in Fremont, 3 runs for $65. http://www.atpturbo.com

Tom

Originally posted by TonyG
My factory Porsche owners manual indicates that the factory power is 172Hp (crank) for the 1982 USA model 911SC.

This means that the 40mm PMO's, 20/21 cams, SSI, recurved distributor, and 2in/2out muffler are worth a combined total of about 70 crank HP!

205 Actual Wheel HP (SAE is used for comparision purposes)
------------------------
.85

=> 241 crank hp

=> 241 crank hp - 172 crank hp (stock)

=> 69 crank hp (and possibly more) increase over stock


Looks like Bruce Anderson is incorrect in his calculations with respect to the added HP for each modification (which people have quoted).

Thoughts? Corrections?

TonyG

[Eagledriver]

The flaw in your calculations is the 172 number to start with. That is a smog pump USA car detuned for emissions. The SC had power listed at 180, 188, and 204 depending on year and ROW or US. Take the 204 Euro engine and do the mods you talk about and you gain about 37 HP not 70.

-Andy

[dd74]

Originally posted by Eagledriver
Take the 204 Euro engine and do the mods you talk about and you gain about 37 HP not 70.

-Andy

Not necessarily. The late Euro 3.0 ('81-'83) had 9.8:1 stock compression, and the 20/21 cams are known more for raising the torque curve higher in the RPMs, than provide more horsepower.

Honestly, with this engine, the real horsepower is going to come from the early large port heads and SSIs. It'll be a nice deep breather.

With that said, I'd think 235-240 hp at the crank.

[boxermania]

I see that the topic has become interesting.....horsepower here and horsepower there.

What is a few horses amongst friends, of course you will see dyno differences, temperature corrections and certainly it is assumed that the engine is in a perfect state of tune.

For instance, the chart above with the AFR in the 12's from 5K on is losing output. It has been proven time and time again that depending on the engine configuration the best power is attained between 12.8 and 13.2. So based on my experience one could see some additional HP if the mixture is leaned out some.

Likewise the spark lead will always affect the HP, I remember early on when we use to "power tune" the cars, since it will position the fire in the cylinder when the most effort can be obtained from the downward stroke of the piston.

On the other hand, turbo cars typically run on the rich end to insure temperature control since these can get away fairly fast and then, Ouch!!!!!

I think that a couple of acceleration runs on third gear with a G-meter should give us a pretty good idea of where the subject car dials in......has anyone here done the G-meter?