3900 swap into Fiero

[Joseph Upson]

Sound good, but too bad it has the fart can look. I hope you can settle on an ECM code so you can get this thing tuned and actually running sometime!

Fart cans on a 4 cylinder import, exhaust cannons on my Fiero. I'm sure they're made much better than the $20 N1 style mufflers on Ebay, at $63 a pop they better be. One thing is for sure, they sound better than the glasspacks that were on it, and were it not for the 4 cylinder mis-use they probably wouldn't be called fart cans. I marvel at why someone would want to make an otherwise slow 4 banger loud and slow.

[Joseph Upson]

Here is an exhaust test that includes the so called fart cans, they sound like anything but a buzzy import. I abandoned code59 for now and went back to 8F. I have a feeling switching to code59 later on might be more successful now that the engine is running.

http://videos.streetfire.net/video/3...led_635875.htm

[RedBird]

Damn! that sounds amazing! those silencers ruin it, but with them out, that is pure sex!

You need to get this thing done and driving so the rest of us can benefit from this. I haven't looked around as of yet but i would like to know what you did for the VVT phaser. i'm sure it's around here somewhere but i haven't seen it. that, and the fact that my car is my DD, are the only things stopping me from putting a 3900 in my sunbird.

[Joseph Upson]

Damn! that sounds amazing! those silencers ruin it, but with them out, that is pure sex!

You need to get this thing done and driving so the rest of us can benefit from this. I haven't looked around as of yet but i would like to know what you did for the VVT phaser. i'm sure it's around here somewhere but i haven't seen it. that, and the fact that my car is my DD, are the only things stopping me from putting a 3900 in my sunbird.

I should be test driving it later today after all of the intake and intercooling plumbing is clamped up. I unlocked the VVT phaser from full retard and let it return to the stock position. I have much better vacuum at idle now.

My cam is reground so it should still perform well advanced, hopefully my bottom end response will be a lot stronger with 5 more inches of vacuum and headers. I have a Zeitronix WBO2 datalogger that has an auxillary output that I'm going to use to retard the cam. I tested it manually and it works because the engine rpm and sound changes when the module is energized.

You can use the shift light logic to control it also (on off) however it has a ~6360 rpm limit and I have my rev limit set around 6500.

I like the way it sounds muffled also, the silencers are a waste. I thought since the mufflers were straight through it would be loud so I shopped around on ebay until I found a silencer that would fit. When I listened to the video I could tell the mufflers were quieter without them.

[CNCguy]

Another yes vote for the race mufflers. They sound very good. Anxious to see what that beast will do.

I am having a hard time getting my head wrapped around what effects the cam travels will have on performance and how it is used to eliminate the EGR. The exhaust residue in the LZ9 LIM that I have suggests that, at some position, the cam timing allows exhaust to go into the intake and makes me wonder if the higher exhaust pressure of a turbo will have an adverse effect when the VVT is at max travel. Maybe... just maybe I think too damn much.

Anyway... great to see that you are making progress Joseph.

[Joseph Upson]

Another yes vote for the race mufflers. They sound very good. Anxious to see what that beast will do.

I am having a hard time getting my head wrapped around what effects the cam travels will have on performance and how it is used to eliminate the EGR. The exhaust residue in the LZ9 LIM that I have suggests that, at some position, the cam timing allows exhaust to go into the intake and makes me wonder if the higher exhaust pressure of a turbo will have an adverse effect when the VVT is at max travel. Maybe... just maybe I think too damn much.

Anyway... great to see that you are making progress Joseph.

From what I've read it's actually the advance that gives the 3900 its EGR effect and are you sure the residue in the intake is not from the PCV feed since it feeds top center of the intake plenum?

In case I didn't mention it here my cylinder pressures are all in the 213-235 range with 4 cylinders at least 220 and the last two cylinders to be tested 5 & 6 213 as a result of the cam advance.

You and I discussed some time ago a difference in the cam specs you measured vs. what Delta camshafts told me. I was given the impression the stock cam specs were a bit narrow in the LSA and that would make sense given I read in my camshaft & valve train book that a narrow LSA favors the EGR effect which could explain what you are seeing in your engine.

When I setup the engine I found that retarding the cam really isn't retarding it much at all but more like putting it in the straight up position since at TDC the intake valve starts to open just as the crank starts to turn off of TDC, suggesting the engine was cammed for peak output with the cam fully retarded and likewise fully advanced with a transition in the middle moving from idle rpm to max rpm.

My reground cam however is cut for high end performance so the intake valve doesn't open until the crank is turned a few degrees off of TDC. Before I had instances of low to no power brakes coming to a stop so starting the cam in the parked/stock position should make for a great improvement.

I'll post a video of the VVT effect at idle later. My dyno simulations show that the engine should produce 350 hp 0n 7 psi at 6500 with the cam parked and 416 hp retarded. I'll look at the simulated static cylinder pressures vs. actual later although they will not be comparable due to the associated engine speeds.

I should have test drive video today.

[CNCguy]

I'm pretty sure about the source of the residue as the UIM is very clean neat the PVC port and there is more buildup as you get closer to the intake valve. It would be logical that advancing the cam would create the EGR effect but I wasn't sure if I was overlooking something.

By chance, did you check compression with the cam retarded? Just curious what effect it would have.

Looking forward to your new videos.

[Joseph Upson]

I'm pretty sure about the source of the residue as the UIM is very clean neat the PVC port and there is more buildup as you get closer to the intake valve. It would be logical that advancing the cam would create the EGR effect but I wasn't sure if I was overlooking something.

By chance, did you check compression with the cam retarded? Just curious what effect it would have.

Looking forward to your new videos.

I wish I had checked the compression while the cam was retarded. I'm sure it was lower as the idle vacuum is significantly increased, I'm estimating having it ready for a test drive in about 2 hrs. I'm definately planning to take it with me today unless the test drive is problematic.

[bob442]

tempting to see...

[ForcedFirebird]

Man, I loke those mufflers, silencers not as much.

Is it me, or does your shoes look like the are on the wrong feet at 30sec in the vid? haha

Give me butterflies in my belly watching your beast finally come to life. I can't wait until we both have that wonderful spooling sound coming from our cars.

What kind of idle RPM are you seeing? The lope when the motor dropped RPM after letting go of the throttle made that cam sound so much nicer, but my have been just because it was about to stall?

What are your cam specs, and how much will it retard? I'm sure it's around here somewhere...