Bugzilla's supercharged destroked 2.4L build

Well its been a while since I have been on here. Not that it really matters. Anyways, I finally got my destroked 2.4L done and running. I had an eight month setback with JE so it took way longer then I wanted. So here is a quick run down of what I did.

- 2.4L Block
- Eagle H-beam rods for a 2.2L
- 2.2L crank (2007-08 is 58x)
- Custom JE pistons setup for 9.25:1 compression
- 2007 style 2.2L head CNC ported intake runners, exhaust runners and combustion chamber (same head as a 2.4L but without VVT. My ECU does not support VVT)
- Comp cams with adjustable cam gears #113400 The cams are for the 1st gen head and have been modified to work with the 2nd gen head
- Oversized Inconel intake and exhaust valves
- ZZP 82# valve springs
- LSJ supercharger modified to fit a LS1 throttle body without an adapter. 2.7" pulley making 9 psi
- ZZP Neutral balance shafts

So the big question, why make a 2.4L smaller? More RPMs, less bottom end power with a smoother powerband helps with traction. This thing turns 8000 rpms and is still pulling. The bad news is that the blower is maxed out with my combo. Cant get boost over 9 psi. So I have a feeling I will be swapping it out for a turbo soon (already have the turbo). I really was shooting for 15 psi. No dyno numbers yet since the build is still fresh but I am estimating around 425 hp at the flywheel. A turbo running more boost should get me over 500 hp at the crank with ease. When I get dyno numbers I will post them.

The good part of the video is at 2:30.

https://youtu.be/wJ2XGcMhgtA

Thanks guys. More to come soon. Just did a photo shoot tonight! Ok so obviously the ecotec isnt powering a slingshot, but it still looks good!

Quote from TravAZ

Low compression at 9psi making around 375hp at the wheels?

I need some more education to understand how this works...

I'm hoping to run 15-16psi through my built 9.5 compression motor and make 400hp at the wheel. I guess ill see what the dyno shows when I get to that point.

Its not really how much boost you run that determines how much power you are going to make. You can have 2 engines (we will call them both 2.4Ls) that both make 400 whp but one does it at 9 psi and the other at 15 psi. The power band will be completely different between the engines. The one that makes 9 psi is actually more efficient. That is mostly due to the head / cams combo. If the head can flow more air in and out of the combustion chamber, then the turbo/supercharger isnt trying as hard to force air through it. Hence, the reason why less boost still makes the same power. At the end of the day, both engines flow the same amount of air, just in a different way and at a different RPM.

Another example.Think of boost like a pressure washer. Even though it makes 150 psi, you are flowing the water through a 1/8" hole. We will call that stock head and cams with lots of boost. Now take your average hose. It has about 15 psi behind it flowing through a 3/4" hole. This will be the low boost engine with a good flowing head. Take the pressure washer and stick it in a bucket for 30 seconds and spray away. Then do the same with the hose. Measure the difference and the hose will be the winner. Not because of how much psi it has behind it (cause the hose does have less psi), but its about the minimal restriction in front of it.

Quote from TravAZ

I get it. I just like to poke at people that estimate power, especially when its that high. Most people don't hit their estimate on a dyno and to me it looks like an aggressive number for that setup at 9psi. Looking forward to seeing the dyno charts to see how close you are to your estimate.

To illustrate your point above, it will be cool to compare your chart to mine. Ill dyno my built motor at 9psi and then turn it up to 15psi. There are several different variables, but it still would be interesting to see the differences for those thinking of building a 2.4.

Poke away all you want. I dont care but I still say it makes 425hp at the crank. Have you ever seen another Ecotec rev to 8k and peak power around there? RPMs play a big role in the power considering HP is just a math equation based on TQ and RPM. Would you believe me if I said I built a carbureted 2.4L that did 300 whp @ 8800 rpms NA?

We can compare dyno charts all day. It would be cool to see. But at the same time, its a dyno. Every dyno reads different. With the click of a button, I can make the dyno say I make 500 whp. But either way, I will throw it on the dyno to get some numbers. It will be going on a Mustang dyno.

Quote from Slingrazor

A good example of the different built motors would be DDMs new cams.
Their SC with the smaller pulley is making 320 HP at 10.5 psi. With the new cams allowing the head to breath better the motor make around 385 HP at the same 10.5 psi.

Great example! I bet the one with cams also peaks power about 5-700 rpms higher. Do you know what the specs on those cams are? Dont see them on DDMs website. I would love to see them add in a ported head to the mix and post results.

Quote from Slingrazor

The red line for our ECUs are around 7300. That is HP at the rear wheel. With the single drive wheel I believe crank is about 35 higher. Most of the numbers you see posted here are at the rear wheel, what is actually on the ground.

Red line and peak power are two different things. I can set my limiter to 8500 rpms but it would be pointless since the engine peaks power around 7800 rpms. If I remember right, a bone stock 2.4L peaks power at 6200 rpms. Having a limiter set at 7300 would be pointless. I would say 7300 is a good limiter for an engine that peaks power at 6900 rpms.

Quote from Neosolidus

DDM said the "more info coming soon" that was said back in January , so i guess that is their version of polaris "in two weeks".

Haha that is very true! Maybe Dave will pop in with some specs.

No dyno yet. I am basing the crank HP off of other builds I have done that were similar. I am also estimating drivetrain loss to be around 15%. That would put me at around 360 whp.