1984 911 3.4 sleeper hotrod - The end?

[gliding_serpent]

You know you have done well when the feedback on your engine is "you may want to look into dialing back the throttle response. It produces too much power too quickly, which makes it more challenging to manage on track."

That was feedback from our chief instructor at a local hpde a month or so ago. The car is a beast, right from the getgo. It really puts hair on your chest. To overuse a cliche, it pulls like a fraight train from any rpm. On the street, you need to be mindful, and you can be "stunting" within a breath or two. On the track it is a monster. 2400lbs wet can do that.

If you know my past two build threads on the car (now useless due to the new photobucket "ransom"), you will know a lot of love, effort and thought went into this car. It became my dream car. Enough talk... here is the dyno: (numbers all at the wheels)



That works out to 290hp at the crank. On 91 octane. Single plug. 92ft above seal level, 23oC. Please feel free to compare the numbers i get at various rpm's to similar builds. Long story short, vs big cammed, big exhaust 3.4l builds, i match the top end, and beat them in the low end.

So what was the formula for my 3.2l? From intake to exhaust... here it is (sort of):
- MAF/injectors/dme/chip with cone intake from Sal Carceller.
- 91 octane fuel
- single plug
- 66mm enlarged throttle body (stock 63mm)
- no extrude hone for intake runners
- 964 cams
- max moritz 3.4l pistons with 9.8:1 compression ratio
- custom 1.5 inch internal diameter headers (i had them built to my spec... with heat)
- custom muffler (designed to my spec)

You will note that everything is quite balanced. No huge cams, no huge exhaust. Just well matched/designed components that are #balanced#. The theory is that the intake plenums are tuned for an optimal peak torque and rpm, so rather than fight it, and try to change that, I worked with it, and worked to optimize it further. My goal was to keep the stock peak torque, and near stock redline. In the end, many small changes became synergistic.

Sal did the tuning on a mustang and i want to thank him very much. Great guy, and huge support. He hooked me up with a very drivable car, and a great system. The car runs like a top. Also thanks to Larry (you know who you are) on the mechanical side.

[Trackrash]

246 HP and a flat torque curve. NICE.

Thanks for the follow up post. Glad to hear that everything turned out great.

[Mad Max]

Wow. 8 pounds per hp is huge. Wish they all were like this.

[-Levi-]

those are some amazing numbers out of a single plug- im actually quite surprised- I will have to dyno my mild v-ram 3.6, those are the kinds of numbers I was expecting out of the newer engines.

ps- its never enough power!!!!

[pooder]

Congratulations on your project. Your build is very similar to mine, except I used SSI's with Dansk sport muffler w/ single out, and your dyno results are nearly identical to mine. Enjoy it, I believe this is as good as it gets.

My '87 3.4 with MAF project

Peter

[Techno Duck]

I have a similar build that resulted in 252whp/230ft-lbs. Mind you, based on the results of other cars on this dyno i think it is optimistic by about 10-15%. Personally i think i am in the 225whp range.

Mahle 3.4L p&c's
Compression 9.65:1
Single plug
91oct
964 cams
Still running stock motronic, dyno tuned on the conservative side for reliability.
Stock headers, this was with an M&K Euro pre-muffler and no primary muffler. We saw ~10hp drop with a M&K single in/out muffler added.

In this chart, the blue curve is with just the pre-muffler. Red is with the full exhaust.

[gliding_serpent]

Originally Posted by pooder

Congratulations on your project. Your build is very similar to mine, except I used SSI's with Dansk sport muffler w/ single out, and your dyno results are nearly identical to mine. Enjoy it, I believe this is as good as it gets.

My '87 3.4 with MAF project

Peter

Yeah, and i was a big skeptic of your dyno from the start... And when I dynoed my car on a mustang first I thought my numbers were inflated, but now I am a believer. Dynos are not perfect, but a dynojet is a dynojet.

[gliding_serpent]

Very interesting. 10% correction on your top numbers (without the muffler) is 267hp at the crank. Drop the cat, Pop on another muffler like a dansk sport and you should drop only 3 or so hp from those max numbers. I know my headers and muffler are worth a lot also, as i designed them to optimize my setup.

Like you, i had had sal tune for a more Conservative afr as i track my car, and favored reliability over a dyno princess.

My belief is that dynojets are generous for our cars, but at least they are about as standardized as they can get.

Originally Posted by Techno Duck

I have a similar build that resulted in 252whp/230ft-lbs. Mind you, based on the results of other cars on this dyno i think it is optimistic by about 10-15%. Personally i think i am in the 225whp range.

Mahle 3.4L p&c's
Compression 9.65:1
Single plug
91oct
964 cams
Still running stock motronic, dyno tuned on the conservative side for reliability.
Stock headers, this was with an M&K Euro pre-muffler and no primary muffler. We saw ~10hp drop with a M&K single in/out muffler added.

In this chart, the blue curve is with just the pre-muffler. Red is with the full exhaust.

[epinfren]

I can't be the only one that would love to see some in car action footage!

[gliding_serpent]

Originally Posted by epinfren

I can't be the only one that would love to see some in car action footage!

I will get some gopro video monday/tuesday at the track

[gliding_serpent]

[gliding_serpent]

[fred cook]

Your engine numbers are going to make me put my car on a dyno! About 4 years ago, I built a 3.3SS engine for my SC using 100mm Mahle 10.8:1 pistons, 964 cams, Carrera race prepped heads, early large port CIS airbox, crankfire Electromotive XDi twin plug ignition and SSI exhausts. Starts and runs well and, like you said, "pulls like a freight train up to redline (7500 rpm)! Now I just got to know what the real hp numbers are!

[gliding_serpent]

Originally Posted by fred cook

Your engine numbers are going to make me put my car on a dyno! About 4 years ago, I built a 3.3SS engine for my SC using 100mm Mahle 10.8:1 pistons, 964 cams, Carrera race prepped heads, early large port CIS airbox, crankfire Electromotive XDi twin plug ignition and SSI exhausts. Starts and runs well and, like you said, "pulls like a freight train up to redline (7500 rpm)! Now I just got to know what the real hp numbers are!

The dogma has been that ssi's will limit top end power to maybe 260-270hp at the wheels, but rumors of unicorns exist. I undrestand those unicorns were heavily worked in race type engines with independant throttle bodies. Mine are all drop in parts, but i admit my exhaust was custom spec. No fancy headwork however. Just the cams. I have yet to see the numbers on a dynojet from such unicorns however.

What interested me was that i expected to see a beefier bottom end with the ssi's. What I found was that the proper sized headers improved my entire power band. Everything shifted up. I have seen some 3.4l dynojet nombers with big cams and exhaust, that lost on the bottom end, and did no better than the top end on my build.

I am not saying i have the one engine to rule them all, but maybe moderation and good intake/exhaust design is key to make the most of a series of small changes.

[911 Rod]

Did you dyno the car before the build to get a baseline?

[gliding_serpent]

Originally Posted by 911 Rod

Did you dyno the car before the build to get a baseline?

Yes. Depending on what you believe, it was about 260hp at the crank with ssi's and a dansk sport. The remainder was the same for the engine.

No baseline on the engine when it was a stock 3.2, but it had way less low end and mid range grunt (it also came with near no muffler and a chip).

[Matt Monson]

Well done, John.

[gliding_serpent]

Originally Posted by Matt Monson

Well done, John.

Thanks, the gearset you helped me put together for our local track is perfect (I run a ~8% shorter ratio) and the LSD has been a great addition. The car puts the power down like a champ, and is very stable under braking. The wevo short shift is also brilliant.

We did a tranny oil (swepco) change this spring and my builder was amazed at how little metal was in the box. Barely anything. He never saw such clean oil in a 915... and my car is frequently tracked too!

[gliding_serpent]

A few more photos

[gliding_serpent]