Bugzilla's supercharged destroked 2.4L build

Your good. We have a lot of smart members here that have some high HP numbers. Just like talking apples to apples so we can compare your numbers and our numbers.

@Bugzilla many of us are watching closely for progress and results as a great opportunity to learn and understand. I am intrigued with the approach and hope all goes as expected.

Quote from Bugzilla

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.

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

With our DDMWorks engines and Rotrex Supercharger kits the rev limiter is peak power . We have ran into restrictions like exhausts and so on but we can and have found ways to over come and push for more. We set our limiter at what we know is safe and what we know makes power.

As far as the cams go we will not be dropping any specs on you guys just yet as that is what you might call proprietary information . Testing has gone well with them and as soon as we get the rest of the package together we will let you all know. Spare time is hard to come by these days and we are not complaining.

Thanks for the continued interest and support . Hopefully we can get some more exciting parts out soon.

The big points here would be this test was done with the Alpha header and 1320 exhaust. These are both limiting factors that can not breath on the top end. Like I said before we have found the limits and found ways around them.
@Slingrazor is one of our most modded customers on a stock engine.

Quote from Bugzilla

Jeff - After doing some searching around on the forum, I found something Dave posted earlier. He also gave away partial cam specs if you know what stock cam specs are... Here is what he said in another post.
"We have been super busy, but finally had time to test some custom cams we had made for us and the results were pretty awesome.

For those that are not super familiar with the cams on the LE5/LE9, the cams have integrated passages in the front that allow oil to flow up to and back from the cam actuators on the front of them. This VVT mechanism is really a nice benefit, but because of the passages in the front of the cams, cam blanks are not available. This has left the options for cams in the past limited to reducing the base circle on the cams slightly, which does increase lift, but does not really change duration much. The duration is what is going to allow the engine to breathe in the upper RPM range and is what we were after with these cams, since it also complimented the power profile of the Rotrex supercharger also. The custom cams we had made for us increased the duration of the intake cam 19 degrees and the exhaust cam duration was increased 25 degrees overall. This allowed the engine to breathe much better on the top end of the RPM range with some drop in torque in the lower RPM range, which was the tradeoff that we were looking for, the end result was 358HP at the wheels @10.5PSI."

So first off, according to this dyno chart, it makes 358hp @ 5700rpms. Looks like the pull was made to 6700rpms. So with the cams, supercharger, header and exhaust peak power is 500rpms sooner then a stock 2.4L? Where is the limiter set on that combo? Not trying to bash, just looking for some clarification.

@Slingrazor What mods do you have? If your limiter is set to 7300rpm, I am guessing you are modded in some way.

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That was a very early test of the cams, without any associated tuning to take advantage of the change in VE of the engine. We also were able to drop a pulley size on that dyno at the same time while still maintaining the same boost pressure as the larger pulley we ran before, which increased the VE of the supercharger in the lower RPM range, ahd had the result of increasing midrange torque. We had tried the smaller pulley's previously, but because of the increase in pressure delta on the supercharger, the net power did not increase like what we saw with the cams installed.

As for the rev limiter on the engine and where to set it, that has more to do with the calculated torque at the wheels and how the engine is making torque. A simple Excel sheet with torque and gear ratios will show exactly where you should shift and what RPM is actually useful in each gear. Although there are times like autocross, where even though you may make more torque at the wheels in the next gear, saving the shift time means it is actually beneficial to hold the same gear out to a higher RPM.

Attached is a sheet that we have done on other setups to show the torque at the wheels. All we do on these graphs is input the torque from a dyno of the vehicle at different engine RPM's (every 250RPM) and the gearing of the transmission and final drive. That will calculate the torque at the wheels and also plot it on the graph. Then you find the point at which they cross and that is your optimal shift point for each gear. Spinning the engine beyond that point means you are making less power at the wheels and you would accelerate quicker in the next gear.

Hope that helps,
Dave

Quote from Bugzilla

So any chance you can release some info? Like on your package with the correct intake and exhaust + cams and a supercharger, where does it peak power? Maybe a dyno graph?

Absolutely, once we release the total package, we will release a lot of information about the best setup.

And that test with Cams and smaller pulley were on a stock engine, a really nice Pearl White SS if I remember correctly....

So, did the cam swap raise the power to 358 or 385? Were the conditions and corrections about the same on both of these dyno sessions? @Slingrazor @Dave@DDMWorks

350hp is A LOT of power on a stock motor. I am sure it is a blast to drive @JoeF.

I think I am going to have a dyno day here in AZ when it comes time to do mine after I go through the lame engine break-in period. That way anyone can come out and see what their machine puts down. I have a great place and I am sure we can get a good rate for a 1/2 day or full day. I will post when it comes time and see if anyone is interested.

@TravAZ
I'll have to defer to Dave on this one. Maybe I got the numbers spun but I think the 358 was early dyno numbers.
I am the idiot who is willing to see what I can do on an unforged motor. I am around 320 now with a motor that has over 30000 miles on it. I have driven it bouncing off the rev limiter for the last year.
You gotta just have fun and see what happens. The cost to build a forged motor from my current one or a used one is not very much apart. For that reason I am driving the heck out of it.

Quote from Slingrazor

@TravAZ
I'll have to defer to Dave on this one. Maybe I got the numbers spun but I think the 358 was early dyno numbers.
I am the idiot who is willing to see what I can do on an unforged motor. I am around 320 now with a motor that has over 30000 miles on it. I have driven it bouncing off the rev limiter for the last year.
You gotta just have fun and see what happens. The cost to build a forged motor from my current one or a used one is not very much apart. For that reason I am driving the heck out of it.

I have to second that... as you know and Dave knows I am the second idiot bouncing and pushing the envelope on a unforged motor - but I am having fun and the forged parts and engine stand is waiting in the garage for when it is time "around 320 rwhp"

Quote from TravAZ

So, did the cam swap raise the power to 358 or 385? Were the conditions and corrections about the same on both of these dyno sessions? @Slingrazor @Dave@DDMWorks

350hp is A LOT of power on a stock motor. I am sure it is a blast to drive @JoeF.

I think I am going to have a dyno day here in AZ when it comes time to do mine after I go through the lame engine break-in period. That way anyone can come out and see what their machine puts down. I have a great place and I am sure we can get a good rate for a 1/2 day or full day. I will post when it comes time and see if anyone is interested.

It was there for the forged engine swap, since I already installed the SC months earlier, was a good time for them to check out some things they had sitting around before they swapped it. Ole stock engine held together great though, tough engine for all that!

Loved reading this thread, except for one thing. RPM is the correct term, RPMS or RPM's is not correct. It is Revolutions Per Minute. Only one minute is measured, not several minutes.

I'll go hide now, but I will still read the thread because y'all are really smart people doing what I wished I could do.

LC