3.2SS with MS EFI dyno results
 

Well, finally got a chance to dyno my recently completed 3.2SS motor, built to the following specs

3.0 SC case, crank, rods
95mm Carrera pistons bored out to 98mm
Custom 9.8:1 JE's
DC40 'ModS' Cam
Large port '79 heads, single plug, EBS racing springs and retainers
Large port stock '79 intake runners, plenum, TB
Tbitz MS EFI
Recurved distributor
SSI's
Custom magnaflow exhaust


Before i give the number, let me just say thanks to all the guys who helped me with this build, first being our own Bruce Abbott (flat6PAC), who took over the task after i decided to restore my car instead of rebuild the motor myself (won't they hurry and start offering cloning), Henry Schmidt on cam advice, and Jamie Novak, on helping me get the initial tune worked out.

Well, our best run was 198whp (which equates to what, 230-240ish at crank?) and 181. However, the numbers only tell part of the story. Torque is everywhere, (even with this cam), and the motor spins like crazy (sachs aluminum PP, but stock flywheel). The motor pulls nicely all the way to 7000, but you get a little extra shove starting at 4000. Basically, exactly what i wanted from the motor.

http://forums.pelicanparts.com/uploa...1251160577.jpg
http://forums.pelicanparts.com/uploa...1251160625.jpg

Little youtube for your entertainment http://www.youtube.com/watch?v=0Wmkf89qd4c

Now, i know, i know, you are asking why i use the stock plenum instead of ITB's? Mainly because it's what i had, and as this is basically a hobby, and i have my son's education to start saving for, i had to draw the line somewhere. Plus, the car is going to Europe for the long run, and i didnt want to have to fiddle with it, as i thought i might with ITB's. Anyhoo, if i want to go ITB's in future, i can always add them and re-tune

Nice numbers, but you could see huge gains from making the ignition programmable from the EFI and get rid of the mechanical advance stuff in the dizzy.
Nice car!

Nice numbers Justin!

And for those who have asked the question before... Yes you can use hot cams like this DC40 with a common plenum intake system. However, you must get rid of the flapper or barn door system on your CIS or Motronic setup, respectively.

I was pleasantly surprised how the car came to life once the EFI was running well. And yes, it pulls hard all the way to redline.

Enjoy the ride Justin!

Oh and bring on the Stem Cell research to accelerate cloning. Although, I don't know if I want another me running around. The world might be in serious trouble if that happens.

can we get some more info on that car, the exhaust exits excite me ! (i don't think i've ever said three ex words in a row before)

Thanks for the comments guys

Raceboy, ITB's and coil packs are definately going to be the next step. For now tho, i basically wanted the motor to be as bulletproof as possible, even at the expense of HP, as she is going to be my transportation in Europe for the next several years. Put her on the boat for Antwerp, Belgium yesterday:D
http://forums.pelicanparts.com/uploa...1251247029.jpg


Jamie, hope all is well down there in Austin and things are cooling down. The tuning and hard breaking in session we did that day really paid off. Cant thank you enough for your advice and input all along the way in this build.

Facey, the exhaust it's basically a magnaflow 2-in, 2-out that with custom pipe work that i shamelessly copied from the GT3 RSR;)

http://forums.pelicanparts.com/uploa...1251246737.jpg
http://forums.pelicanparts.com/uploa...1251246835.jpg

Pretty happy with the sound. Muted enought at idle and around town (which is important in Europe) but sounds old-school raspy when u crack it. http://www.youtube.com/watch?v=K8HDLIlY7gM

BTW, in case u r interested, i started a thread on the upcoming european excursion and sort of a 'cliff notes' version of the highlights of the build here http://forums.pelicanparts.com/porsche-911-technical-forum/494094-targa-sicily.html

Nice torque curve. Are these the normal DC40 cams on a 102 lobe center, or the wide LC version on 108 degrees?

Justin, Do you have a graph with rpm values? What are the rpms for peak torque and HP? Do you have the AFR curves that correlate?

Thanks

John what does the wide lobe 108 give please ?

Hi,

These look like honest numbers. I am always a bit suspisious of the 3.0 with 250rwhp. I know that each dyno is different but seeing these numbers and the torque curve demonstates a dyno operator that is not trying to impress his clients by producing unrealistic figures.

My last dyno run was only a few weeks ago and it produced 204rwhp....significantly down on some figures posted here. My question to the dyno guy was how does that compare to other cars on this dyno. As it turns out comparable to a mild tuned V8 5.0.

Nice unique car and good numbers enjoy the driving in Europ.

Mark......

Jamie, here ya go
http://forums.pelicanparts.com/uploa...1251377933.jpg

John, this was the 108 LC cam.

Mark, thanks. I can tell there is a bit more to be obtained from this motor (freer flowing headers, ITB's, programmable ignition), but as is, it should be a dependable and fun motor.

Justin, Thanks for posting the rest of the picture.

OK, now if it will just cool off a bit I will get some numbers on my motor. Same displacement and cams yet, more compression, twin plug, ITBs and headers. This will be a good test case to see the differences.

Yes, you should have a very fun, reliable motor with that build.

Sounds like a great setup, I am looking to do something similar in the next year, however one concern I have and is worth paying some attention to is the use of a catalytic converter. I see several countries in Europe creating zones around cities where cars without converters will not be allowed in. I believe this would indicate that in the future a car for sale would gain a better price if it has a cat. This environmental stand is only going to get worse in my opinion.

Is there an alternative available to get better exhaust performance while retaining the cat?

You could get generic sport cats with 200 holes or even 100 holes?

The wide lobe center (108) gives you a long flat powerband vs. the narrow centers (102). For street driven stuff with EFI the wider centers work better. In most cases anyways.

I don't like the correction factor of 1.00. Was the humidity only 35% when you made the runs? Just a guess, but in North Carolina in the summer, shouldnt you see a 1.02+ correction factor?

No to be argumentative, just curious. My 2.7L chassis dyno sheet with Solex cams(97 deg lobe centers) is nearly a direct over lay of the shown graph. My motor more compression & Webers. With 30 more cubes this motor should look mine look kinda weak. What am I missing?

JP,

Every dyno is different and it is hard to make comparisions. Even with corrections the Dyno operators tend to, shall we say "exagerate" figures to keep clients happy. With the engine build that Juicerrsr has it is a very strong engine and only if you put both cars on the dyno at the same time would you really know the difference. You will see from munerous posts on this forum that unless two cars are on the same dyno straight after each other a direct comparison results in disapointment. If you are happy with your engine, which you obviously are, then try to avoid comparisions. Juicerrsr has quite a bit more to gain from mode to his engine. I am looking forward to hearing future results.

Cheers

Mark.....

Thanks for the education. You have made 2 assumptions here that may or may not be valid....but let's not compare.:rolleyes:

It wasn't the only the ultimate numbers that got me wondering, it was the torque & HP curves. They are nearly identical with only differences the charting.

Camgrinder wrote that the wide lobe spacing was better for a flat torque cruve.....this isn't borne out on these 2 engines.....and numbers are all we have to go on. My peak torque is at 3800 & drops off at 5500. Peak HP is at 6300 dropping off 4 hp at 6800.

This exhaust system is fairly restrictive which hurts his top end power. I dont remember seeing a dyno sheet with SSI's that carried HP much past 6200 rpm. And this one shows maybe a 5 hp drop at 6800? There is a lot left in this combination.
Dropping the AFR from 14-1, would be a good place to start.

The 2.7 and the 3.0 share the same 70.4 mm stroke which has a lot to do with the powerband. But, This engine has a plenum intake system. Not really comparing apples to apples in my opinion.

I am curious about your 2.7 dyno sheet, post it up?

Your wish is my command.:D
Kinda hard to read from my scan job, sorry. I got a song & dance about the "squiggels" .......http://forums.pelicanparts.com/uploa...1251428202.jpg

JP, nice motor

One thing to remember is that i built this motor for a car that will be driven all over Europe, including to places like Russia, Turkey and the middle east, as well as some track and rally events. To that extent, i made compromises - Restrictive SSI's for heat, Factory Intake and TB for simplicity, and as John pointed out, an AFR on the slightly rich side, in case i get some crummy gas in Bulgaria or wherever. All of these add up to severely limiting the potential, and bringing the curves closer to your motor. However, the motor is very torquey and flexible in a way that the 2.7 in my 914 is not.

Jamie, hurry up and dyno your motor so that we can see what a maxed out 3.2SS is truly capable of!!

Actually, 14-1 is on the lean side. Getting the AFR closer to 12.5-1 will net you more HP.

JP, nice dyno sheet. Hard to read all the numbers, but it looks like you are over 180 ft lbs from 3700 to 5300 rpm? 180 being 10 down from the peak number.
Looking at Justins curve, he peaks at 181 and comparing 10 down from the peak would be 171 ft lbs from 3600 to 6100 rpm. (as close as I can get from pictures) I'm not trying to compare ft lbs numbers from yours to his, just the shape of the curve.
If you could move your torque curve up another 500 rpm, you could make 175 ft lbs at 6200 and have 206 HP.

I looked, but could not find a dyno sheets on the DC30 cams. My 102 lobe center version of the solex grind. Would be fun to compare to JP's sheet.

My goof, i gotta get more sleep...:rolleyes:

Gonna fatten things up when over there.

BTW, Jamie, didn't you say you were running your AFR's a little on the lean side?

I do run lean but only at the cruise states, part throttle. Anything over 90 kPa (near to and WOT) is pinned rich. I go about 13.1:1 up to peak torque and then drop to 12.8:1 from there to redline.

btw, I do not have dyno numbers on my motor yet. However, I can tell you that my peak torque is about 5500-5800 rpm based upon the fuel delivery curves at WOT. The curve follows closely the effciency of the engine where peak torque requires the greatest amount of fuel. I can't wait to get it on the rollers to see how close the tune actually is. This should happen in the next month or so. The heat is finally starting to break. Yesterday was the first non-triple-digit day in about 2 months. I really don't drive the car at all during the summer and don't feel comfortable stressing the motor in a static position on the dyno in the heat. Cooling fans help, but only so much without full dynamic air-flow from a moving car.

One thing interesting to me is that from 4-5K you are running below 13:1 (red dotted line) then from 5-6K you are running near 14:1. If you look at the torque curve shape you will see there is a dip between 4-5K and a slight rise from 5-6K. This says that you either have very good cylinder mixing to burn all the air near stoichiometric 14.7:1 or something else is up. I don't have an answer for that one.

Either way. I certainly thought the car was a lot of fun. It was much improved compared to a stock CIS 3.0. And it certainly doesn't fall flat above 5500 rpm like stock.

John:
Thanks for the complements. Sorry about the bad reproduction. It does make for a challenging read.

A couple things to ad. It is an autocross motor and I did what I felt I could to get the torque down low. The pulls were done after only 30 minutes of dyno break in time on the NOS 10.4:1 P/Cs & without benefit of anything but my basic tune......the engine "woke up" after 4 or 5 AX passes a week later.:D A switch to leaded 110 (vs the unleaded 99) this season made the fuel burn much better (single plug).....no more gouts of black smoke when clearing its throat & better throttle response along with more pull per my butt dyno. I agree that the numbers comparison of the 2 engines is truly apples to oranges as another poster wrote.
The cams are Solex....one NOS in the wrapper and the other "touched up" by Web Cams. They are center oilers, of course. I was in a bit of a quandary about what to do with that feature, but finally plugged them at the drive end ( this was 7-8 years back).:confused: Home builders do a lot of :confused:, me thinks.:D

It would neat to see another chart using your 102 lobe center cams.