4G63 on an Engine Dyno

[bastarddsm]

So end of last month I was fortunate enough to get to spend an entire day playing on an engine dyno. Ended up making about 15pulls. I have been experimenting with a new engine control system that I wrote the software for, so it was nice to proof that it actually works as expected.

I've been street tuning for years, and I thought I had a pretty good handle on getting a good tune without using the dyno. Turns out I was right, and my street tune was just about perfect. I actually use a MAF on this system so I had very little tuning to do on the fuel side. I often get chastised for my view on speed density being obsolete, and a maf being better. My dyno session ended up being a perfect example of why this was true. Over multiple cam timing settings, 3 different intake manifolds, and multiple boost settings, didn't have to touch anything on the fuel side to maintain my target AFR.

As for the dyno testing I went in search of testing a few intake manifolds, and what they do to the power curve as well as cam timing and it's effects. I was also looking to find where ignition timing wanted to be. Turns out it's a lot lower than I expected. At 34psi it seems my street tune was 2* and 20hp shy of MBT timing, which was a shocker. I figured it was at least 5* low.

I ended up making 725hp at 34psi, and picking up almost 100HP at 5500RPM by an intake swap and intake cam timing adjustment, while loosing only 19hp at 8200.

The amount of data I received was overwhelming. I will be able to calculate turbine and compressor efficiency's. I am running a Garret custom GT3788 AVNT turbo that I built. I modified the cold side to use a TO4S cover instead of the weird diesel truck one, as well as fitted a larger turbine, and reshaped the vgt vanes for better flow. As such it is invaluable to be able to calculate the efficiencies of the turbine and compressor.

Anyway here's a video of a 700+ 4g63 on an engine dyno. Pull from 4600-8200

You must be logged in to view this image or video.

 

[Kapok6]

What MAF do you use?

 

[Vegas Smith]

What MAF do you use?

1G mas, honeycomb removed. Dejon tool intake.

BDSM, how are you determining how much timing to run on the street? That always seems like a nebulous process to me.

 

[donniekak]

Super curious what this would put down through a dynojet.

 

[Boomdeeze]

What intake cam timing change did you make?

 

[kronus]

So for those of us who prefer to VTA (because I’m a ricer inside) would you recommend leaving a SD setup in favor of the GM MAF or is SD still superior to that?

 

[Kapok6]

1G mas, honeycomb removed. Dejon tool intake.

BDSM, how are you determining how much timing to run on the street? That always seems like a nebulous process to me.

Wow. I didn't know a 1g MAS could flow enough air for 725hp. Geeze.

 

[95REGF150]

If you don't mind sharing, what intake manifolds were you testing? Were they custom setups or something available such as Magnus, etc? 100 HP is a crazy gain from just the intake manifold which ever you were using before was a real choke point lower in the curve.

Also how are you deciding to make changes to your cam timing? I have heard from many that it is simply trial and error to see what makes the most power on the Dyno. But you seem to have much more of a plan when it comes to these things.

 

[bastarddsm]

What MAF do you use?

I am using a PMAS HPX-F2 It's a Hitachi slot maf with a frequency output that's been modded. Supposedly it'll measure 100lb/min in a 2.5" tube. I'm seeing right about 70 and it's right on with the data they provided.

I did use this on a 1g ecu with some custom code last winter. I had it working decently, but it needed more work yet. I'm pretty sure it could it could be used with ecmlink and their gm maf cable.

1G mas, honeycomb removed. Dejon tool intake.

BDSM, how are you determining how much timing to run on the street? That always seems like a nebulous process to me.

On timing, I figure it out by reading plugs, trap speeds, and head gasket life. This has a $26 felpro and more than a decade old standard ARP's btw.

Super curious what this would put down through a dynojet.

I know, me too! I want to do it, but I just can't afford to right now. Can we get a donation together? Best as I can figure from comparing datalogs, this would be right around 138mph traps at this power. I figure it's probably 650whp. 2 years ago this setup made 640 at the front wheels on a DJ 248. That was as 40ish psi, but the tune wasn't as good, and a crappy intake.

 

[bastarddsm]

So for those of us who prefer to VTA (because I’m a ricer inside) would you recommend leaving a SD setup in favor of the GM MAF or is SD still superior to that?

Personally I'd reccomend a 2g or evo maf an recirculating your bov, unless your looking for 600+hp. Then I dunno. I ran a GM maf before this, and didn't have much trouble until I got to 70lbs/min. Not sure if that was overrunning it or the MAFT was damaged by getting too much water in it.

If you don't mind sharing, what intake manifolds were you testing? Were they custom setups or something available such as Magnus, etc? 100 HP is a crazy gain from just the intake manifold which ever you were using before was a real choke point lower in the curve.

Also how are you deciding to make changes to your cam timing? I have heard from many that it is simply trial and error to see what makes the most power on the Dyno. But you seem to have much more of a plan when it comes to these things.

I'm not sure how much info on the intakes I want to give away. The data was very very hard earned. Plus it would just start a big shit flinging contest. And yes cam timing is cut and try. It helps if you have some intuition and an idea what changes will result in what effect. You also should have a goal to accomplish. I can tell you from past experience that shooting for a big number at 9000RPM does not make a fast dsm.

 

[Galant665]

I have had good luck also with the off the shelf Fel-Pro HG. And standard ARP studs. 40 psi and still holding.

 

[Kapok6]

Composite gasket is all I use.

 

[donniekak]

Personally I'd reccomend a 2g or evo maf an recirculating your bov, unless your looking for 600+hp. Then I dunno. I ran a GM maf before this, and didn't have much trouble until I got to 70lbs/min. Not sure if that was overrunning it or the MAFT was damaged by getting too much water in it.



I'm not sure how much info on the intakes I want to give away. The data was very very hard earned. Plus it would just start a big sh** flinging contest. And yes cam timing is cut and try. It helps if you have some intuition and an idea what changes will result in what effect. You also should have a goal to accomplish. I can tell you from past experience that shooting for a big number at 9000RPM does not make a fast dsm.

I made 600 with a hair under 400 lb/ft. The car was a dog. Going smaller cam/hotside knocked off almost 70hp, but the spool gains made the car faster.