[348] Low emission max high HP with cats

Howdy folks

Think I'm all done playing with the 348 for now.
Been messing with it for a year.
~Ported TB's
~Fully adjustible fuel rail system
~Port matched cyl heads and intake
~All emission equipment verified working 100%, this took quite a bit of work btw
~Cats- CARB legal 2 stage, big fat boys.
~X pipe exhaust no mufflers
*Smoke tested and repaired all intake and emission control leaks, very crucial to performance and just about everything leaked
*Tuned the ECU 4 times until I got something I really liked for the street. Dyno verified @ 315-320 hp at the hubs. 315 is what works best due to the nice low and mid range torque where most of my driving is. I drive like Granda Ma Ma

Anyway the deal was to get this thing to run like a champ and pass our California strict emissions

We did really well


HC
10 @15 mph - pass is 50
14 @15 mph - pass is 85


CO %
0.01 @15 mph - pass is .50
0.01@ 25 mph - pass is .47

NO (ppm)
.00 @ 15mph - pass is 695
.00 @ 25mph - pass is 717


This is pretty maxed out for the 348 in a "stock" configuration and proves you can make them clean and run.

Up next winter, ITBs or a turbo with aftermarket ECU

Until then going to enjoy the summer driving season



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Nice work and nice numbers!

What brand dyno were you on?

 

Thanks

I think mustang, I ment at hubs not wheels I will correct that, did not pay attention was same one each time

Going to another dyno

 

Hubs? dynapack possibly?
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Clean means HP. O2, CO and HC out the tail pipe is just wasted HP.

You're burning it all, good work.

 

Agree, great results.

Under the light load conditions that the test is run, sure. But you still are going to want to have higher HC emissions for peak power. You cannot burn all the available oxygen with a stoic mixture- reactions are not perfect in a cylinder. Also the richer mixture runs cooler making the engine less prone to knock and protect the combustion chamber components.

 

Yeah thats the one, ugly sucker for sure

Thanks

Yeah its easy to flood it with fuel and spark but more challenging this way
What else can old dudes do in retirement LOL

 

Amazing, those are close to F355 hp numbers!

 

And the 348 is only a tad heavier than the F355, so equality can be achieved via driver size.

 

How is the 348 heavier than a 355 with no power steering or electronic shocks? I've never looked into this and you've made me curious.

 

As per the workshop manuals, but there are weight differences between US and Euro cars as well.

The 355 also has lighter mag wheels.

But yeah, on the surface, it seems (to me) that the 348 would be lighter (the F355 looks "plumper").

Oh, and sometimes it's difficult to find apples to apples data for the models e.g. weights - dry, curb/kerb and gross vehicle weight rating (GVWR).

 

Tim's Challenge 348 has the Speedline Challenge wheels. I am sure that car is lighter than any 355.

Tim, how much pressure are you running in the rails? I have been thinking about an adjustable fuel pressure regulator to boost fuel in. My intake and TB's are ported and polished already. I'm leaving the muffler in, thinking about headers though. Next step, however, will be valves and ECU. Let's see just how far we can take this stock set up. I just might spin it up a bit further.

 

I run 50 to pass emission LOL and pump it to 65-70 and get to 12.5-1 afr
Damn thing just smokes the tires soon as I let it off the clutch.

Also no muffler just strait pipes at all so yes it lost weight


Not sure I would spend on headers unless your after max HP at redline, stock are best for street driving real nice torque curve

Remeind me next time your here to get you the better ships, not that sissy challenge stuff

 

Thanks for sharing the info, Tim.

What injectors are you using-- the later 4 hole version in the stock flow rate?

 

I have stock, upgraded 4 hole and a set of 355 that are going in next

Stock is fine with the modded ecu chips just a different way to get fuel in. Must have a wideband AFR on both banks because both sides do not run the same always so I adjust both banks as separate motors with the plenum divider closed