84-89 3.2L upgraded to 3.5L with 267 Wheel HP!

[scarceller]

Wanted to share a 3.2L upgraded to 3.5L recipe that produced the best best results I've personally been involved with.

This build belongs to Mark Palmer, he built the engine with my design guidance and assistance.

Before I go into the recipe here's the dyno results.
- You see 2 result pulls over-layed. The blue lines are from the initial build that used GHL SSI Heat Exchangers, SSIs are completely wrong for any 3.2L not just because of size but because they are not the correct length to compliment the 3.2L intake.
- The Red lines are the exact same engine but with a custom built set of headers and exhaust that was designed and built from scratch to perfectly match the 3.2L intake. The exhaust really matters! Again the only change made between the 2 pulls was the exhaust!

Here's the dyno results:



This is the best result I've had for any of my MAF Systems so far. The owner Mark does a lot of DE events with this 911, it's strictly a track car but with excellent street drive-ability. The car weighs in at around 2300LBs and has no problem keeping up with many newer 911s on the track. I'll invite Mark to add comments to this thread later.

267WHP is around 314 crank HP (15% drivetrain loss). Take note of the torque produced at 4200RPMs, around 220ftlb of torque! This is the secret sauce for any track car! It's what really shines on the track and why this car does so well even against much more modern day GT4 cars! This Engine really has what you need to exit the corners quickly. Large HP numbers at the very hi-RPM are good but the low end torque is so important and can not be overlooked. Compare the torque curves of old dyno result with SSIs vs the new results.

So, what's the recipe? Here it is:

Started life as a basic 3.2L that was upgraded to 3.5L Twin Plugged
• Stock crank
• LN Engineering 3.5L, using 100mm bore slip fit cyls.
o https://lnengineering.com/porsche-911-32-100mm-nickies-inc-105-1-je-piston-set.html
• 10.5:1 CR,
• Twin plug with my custom Carceller Twin Plug Harness and circuit
• My custom MAF System, with 30lb injectors
• Heads done by Steve Wiener on Rennsport. No Port work done.
• 20/21 cams, will work well at 10.5:1 static compression.
Exhaust is very custom, see pics below in next post.

Few important points:
- You can not use the stock air meter with HP numbers this large, it's out of headroom! We moved from the stock AFM that has a max flow of around 13,000g/min to my MAF that can handle 19,000g/min.
- You can not use stock injectors, they are not large enough to fuel this Engine! We used 30lb Bosch OEM injectors.
- Notice who did the heads, Rennsport! The head work really matters and the correct choice for valve springs and proper setup for the springs is a big deal. Do not get this wrong!
- SSIs are completely wrong for the 3.2L engine, notice how the headers helped everywhere along the 2500-6800 RPM range! The SSIs do not help low RPMs, that's just not true. I have other engines that also showed that SSIs are wrong even for single plug motors!

[scarceller]

Exhaust pics for the custom headers:

[porschyard]

Very nice Sal, one of these days i will get back on the 3.2 with your chip/injector package.

Richard

[David 23]

Thanks for posting this. I'd love to see more detailed pics and explanation of the exhaust characteristics that made the significant difference in performance. Is that a stock GT3 muffler or has it been internally modified? In the photo it looks like the header collector narrows down to a "normal" size flanged outlet, but then the pipe joining it seems to open up to a larger diameter. Is that just an illusion in the photo, or is there actually a relative constriction where the collector and the single pipe to the muffler are bolted together?

[scarceller]

The secondary pipe is 2.5" but the outlet on the collector is only 2" if we did this again that collector would be 2.5" outlet. The headers have the outlet to mate up with other common stock setup Mufflers.

The muffler is a just a GT3 muffler but only using the 2.5" non restricted inlets. The other 2 restricted inlets are capped off.

Nothing fancy here, but the 2.5" secondary is also done by calculations using PipeMax software.

Originally Posted by David 23

Thanks for posting this. I'd love to see more detailed pics and explanation of the exhaust characteristics that made the significant difference in performance. Is that a stock GT3 muffler or has it been internally modified? In the photo it looks like the header collector narrows down to a "normal" size flanged outlet, but then the pipe joining it seems to open up to a larger diameter. Is that just an illusion in the photo, or is there actually a relative constriction where the collector and the single pipe to the muffler are bolted together?

[robcf]

Other than camshafts, spring installation and your MAF are there any other changes to the induction of the motor?

You specifically mentioned the ports were left alone (stock?)

Valves?

Intake manifold?

Throttle body?

Thanks,

Rob

[scarceller]

The TB should be bored.
The intake can be stock, no need to extrude hone.
Valves are stock.

But if you have the money spend it on head porting and flow work, it's expensive but worth it if you can swing the costs.

Another point: you can build this same recipe as a single plug and get great results. Like this customer thread that did much the same with single plug. But see exhaust.

https://forums.pelicanparts.com/porsche-911-technical-forum/962997-1984-911-3-4-sleeper-hotrod-end.html

This single plug did very well, but it would do even better with 10.3:1 compression, the 9.8:1 is a bit low but it still did very well.

Originally Posted by robcf

Other than camshafts, spring installation and your MAF are there any other changes to the induction of the motor?

You specifically mentioned the ports were left alone (stock?)

Valves?

Intake manifold?

Throttle body?

Thanks,

Rob

[Mr. Merk]

Would love to listen to a video of this thing

[3rd_gear_Ted]

The underbody diffuser is awesome.
Curiosity about the holes in the diffuser??

[RarlyL8]

Very nice!
I'm seeing similar results on systems we are doing for 3.4L - 4.0L engines. One thing that would create an additional gain is to use 2.25" at the collector.

[scarceller]

Brian, the secondary going to the GT3 is 2.5" pipe. I agree that the collector outlet could be larger.

I know you also have these headers available now, that's great news. This set was custom built but your new long tube headers are basically the same design. What we need is a set of headers like this design but with 2.5" secondary mated to a decent muffler like the GT3 design.

I have another customer that just ordered your MK headers we will get dyno results before and after.

Originally Posted by RarlyL8

Very nice!
I'm seeing similar results on systems we are doing for 3.4L - 4.0L engines. One thing that would create an additional gain is to use 2.25" at the collector.

[scarceller]

I asked the owner Mark to chime in on this thread, hopefully he does. He built the motor and a ton of other work on that chassis. This 911 has a lot of tricked out items and more to come.

Originally Posted by 3rd_gear_Ted

The underbody diffuser is awesome.
Curiosity about the holes in the diffuser??

[scarceller]

The exhaust is completely heat wrapped:



This helps keep things cooler.

[Josh D]

Nice to see data showing the correlation of exhaust design with intake design. This is true of any internal combustion engine. I never subscribed to the claims that the SSI, or original HE design was less effective on the 3.2 than 3.0 and smaller due to pipe diameter.

[Classic 911]

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[Geneman]

Sal. that diffuser is amazing. can you expand on how it was made? what material;? custom? i am running a modified GT3 muffler also, and that diffuser would solve alot of problems. tHank you FRank

[Flojo]

Originally Posted by scarceller

The exhaust is completely heat wrapped:

This helps keep things cooler.

I learned in this forum that you don't heat-wrap headers on a 911 as you don't want heat to crawl back into the engine on a halt, the pipes should be able to radiate to cool.

what is correct?

[75 911s]

I wish someone would copy the guts of the GT3 Muffler and make it look more retro and less expensive.

[scarceller]

Would be nice if someone built an active 4in2out exhaust. This muffler would have 4 inlets 2 on each side much like the GT3 setup. 2 inlets internally would be unrestricted and straight shot to the 2 outlets, these unrestricted inlets would have a vacuum actuated shutoff valve that would fully close these inlets if the valve has vacuum applied. The other 2 inlets would be internally baffled prior to exiting via the outlets. The restricted inlets would not need any shutoff valves.

The unrestricted inlets should be 2.5" and the restricted inlets can be smaller 2.25" if desired.

Then simply plum the vacuum valves to intake vacuum, this will close those unrestricted inlets if the intake has vacuum like Part Throttle or Idle but after 50% throttle the inlets will fully open. Or get fancy with some sort of RPM switch to activate the inlets above 3800RPMs.

The description above describes the stock GT3 muffler.

Originally Posted by 75 911s

I wish someone would copy the guts of the GT3 Muffler and make it look more retro and less expensive.

[75 911s]

Sal what are your thoughts on achieving displacement through stroke vs jug size on the carrera block? I know some have concerns about a thin sidewall at 102mm. So you could achieve similar displacement at 3.55 with a 80.4 stroke and 98mm pistons. BTW thank you for being transparent on the build. These types of posts are invaluable to the community and I doubt they hurt any builders as most are going to opt for pro help in the end when it comes to such an expensive build.