3900 swap into Fiero

[ForcedFirebird]

That thing definately has some torque. The front end raising looks a lot like my neighbor's 327 Fiero (350hp crate) when I rode in it.

I can't wait for you to finalize the tune and really get on it

[Joseph Upson]

That thing definately has some torque. The front end raising looks a lot like my neighbor's 327 Fiero (350hp crate) when I rode in it.

I can't wait for you to finalize the tune and really get on it

It has a lot more in it, I just discovered in a bin comparison that I reduced spark timing by about 3 degrees or more as a precaution at 7 psi above 3000 rpm so that definately had a power reducing effect. Since the engine showed a lot of reserve against detonation despite being very lean in some boost areas it should have quite a bit of improvement left in it once tuned properly without upping the boost right away. 10 psi should make it very interesting to drive, 15 will very likely be scary as twice it has nearly gotten sideways on me.

[Joseph Upson]

Here are a couple of pictures lifted from the part of the video that was edited out. I have about 80% intercooler efficiency using a 27x6x3.5 unit with a 19" long core if I recall correctly. After install I realized I could have gone with a 7" to 8" tall unit but they are hard to find at the price I paid with the tank fittings centered. Hopefully the water/meth kit will bring me very close to 100%. My compressor efficiency will actually climb as I turn the boost up, right now it is at about 55% at 7 psi, that's why the non intercooled air temps were so high at 212 F. Turbocalc is pretty close to the values I'm seeing and it shows with my turbos that compressor efficiency will not improve above 70% until at least 10 psi is reached so my air temps should hold steady or decrease as boost is increased.

[Joseph Upson]

Still didn't get much if any tuning done although some extremely lean areas in the low rpm range were cleared up and probably pushed to the opposite extreme.
Advance Auto Parts shift cables need to be replaced with better quality cables, they are not rigid enough and can not take the heat, I left the car with a seized selector cable. You can note the delay between the 1-2 shift at the beginning of the video due to flimsy shift cables.

On a half tank of 87 octane the car ran very strong at what appeared to be as much as 8 psi, there is plenty of room for improvement at that boost level with higher octane fuel and installation of the alcohol injection kit. The two changes together should make 15 psi very easy and probably attainable with just one or the other. 12 psi should be more than enough given how strong it runs at 7psi.

Unfortunately the datalogs were saved to a corrupt file I discovered a little while ago so I have nothing to take snap shots of to show inlet temps and boost pressure.

I removed the mufflers as a precaution since the body supports have not been installed yet. Hopefully it will be finished by the end of the year.

http://videos.streetfire.net/video/Testing-with-without_680592.htm

[Joseph Upson]

I'm now in the process of changing over to a single turbo setup from the twins. I did a few runs with the GTech installed and if CNCguy is correct and I do believe he is, the cam is advanced entirely too far. The GTech is pretty accurate from track testing I observed and it measures net horsepower which is a little less than dyno testing at the wheels.

The car felt very fast but it is nowhere near as fast as it should be 202hp and 250 lb/ft all at just over 4000 rpm which is 2000 rpm short of what it should be peaking at, a sign the cam position is limiting power. When I retarded the cam it ran even worse with both power and torque under 200. I'll be degreeing the cam in ofcourse and I'm sure there was more power in it had it been tuned, it was rich on the top end and set a code 45. In Desktop Dyno the max I could advance the cam is 15 deg and that dropped power at 7psi down to about 300, CNCguy said full advance is about 30 deg so the additional 15 I can't test in the program along with a poor tune makes it about right although I believe Desktop does power at the crank. I'll be testing it again after the turbo install and cam degree in to see what happens.

[CNCguy]

Good to see you back on your car. I'm curious to see what numbers you get when you degree the cam in and how they compare to the numbers from the CMM.

[Joseph Upson]

Good to see you back on your car. I'm curious to see what numbers you get when you degree the cam in and how they compare to the numbers from the CMM.

I believe the timing under boost is too conservative also, I'm still ecstatic that the few incidents of knock retard of about 1.5 deg all occured around idle rpm where I know the timing is too far advanced above stock Turbo Grand Prix timing. I put 2.5 gal of 88 octane fuel in it after the tank closed in on empty so there is plenty of room for boost, the test runs were made with that fuel grade. The manifold modification for the turbo is comming along well and I expect to have it installed tomorrow. The setup is much, much, much cleaner now with the turbo hidden partially under the trunk and a crossover pipe tucked neatly over the bellhousing an added bonus is the air filters used for the twins are universal and will clamp right on the 4" inlet of the T67 turbo.

I just hope correcting the cam produces the expected improvement.

[Joseph Upson]

Forgot to mention there was an exhaust leak at 3 of the header ports loud enough to hear in the car.

[Joseph Upson]

The flange is welded up, the exhaust should be relatively short. I'll have to divide the 3" pipe into dual 2.25" outlets which shouldn't be too tuff since the engine and cradle will be removed for cam degreeing and flywheel install.

I had to figure out a way to lock the dual mass flywheel and after giving it some thought I found myself at the machine shop. I had the pressure plate bolt holes chased all the way down through the base to stake the top half of the flywheel to the bottom. Some dual mass flywheels are torque limited and will slip, that's the reason for this modification. The top half is not tightened to the bottom, the screws just thread down into the bottom half but tighten against the pressure plate.

[robertisaar]

the flywheel slips? WTF?

[Joseph Upson]

If you exceed its capacity it will, that's by design. Some of the vettes with dualmass flywheels have this function also. Not all dual mass flywheels have this built in fuse.

[Joseph Upson]

Making progress towards getting the engine put back in the car. After addressing the camshaft I found that my 112 degree intake centerline was actually occuring at 92 degrees with the cam fully advanced so no doubt that's killing a good bit of power. I used my extra module to determine the thickness of the spacer I would need as seen on the engine, then I carefully removed the back side screws from the sprung module that would be used, carefully replacing them with drill bits to keep the forward hub that would normally be on the front of the module from releasing the recoil load which would be very difficult to restore if you let it unwind. I also placed about a .040" thick piece aluminum in front of the phaser to partially retard it from full advance to move it a little closer toward proper alignment for a little better baseline performance than what was present previously.

The stock cam would probably perform much better fully advanced than my reground cam. Interestingly two other 3900 swappers were not able to start their engines with the cam fully retarded. I could, however, their horsepower levels were about the same as mine if not a little more naturally aspirated and I'm running 7 psi, not sure what their torque levels were but that goes to show you how important camshaft position and grind is. My reground camshaft is probably more sensitive to position as a result.

On closer inspection I also found that 5 out of the 6 exhaust ports had a leak at the flange so that certainly cost power. I found several potential problems during the tear down, coolant seapage at the upper coolant crossover between the heads (reused gaskets without RTV), and a leaking radiator upon removal for replacement with an HD 3 row aluminum rad. I'll have to reinstall the turbo oil drain a little lower in the pan side due to the turbos level which is more unscheduled work along with the blown brake caliper I discovered and the two brake hoses I ruined by forgetting to disconnect them.

The end result will be a lot cleaner and spacey, I would never trade this exhaust configuration to go back to headers.

[CNCguy]

Very interesting Joseph. Thanks for taking the time to measure and post the numbers. The measurement taken on the CMM was 17.88 degrees max advance which is just over 2 degrees from the installed numbers. Perhaps the phaser wasn't at it's full limit when the CMM measurement was taken or there is some stack up error from the manufacturing process. That is the reason they make adjustable timing chain sets.

The turbo setup on the stock manifold looks great, like it was made to be mounted there from the factory. It's a clean setup that should be very durable.

Any timeline on when you will have it running again? As always, I am anxious to see your progress and results.

On a side note, the three M6 screws that attach the phaser to the cam seem a little on the small side. Hopefully they don't become an issue when people start putting big cams in these engines. Of course, I was never a fan of the single bolt setup on the earlier engines. The old three M8 bolt setup seemed quite reliable.

[Joseph Upson]

Very interesting Joseph. Thanks for taking the time to measure and post the numbers. The measurement taken on the CMM was 17.88 degrees max advance which is just over 2 degrees from the installed numbers. Perhaps the phaser wasn't at it's full limit when the CMM measurement was taken or there is some stack up error from the manufacturing process. That is the reason they make adjustable timing chain sets.

The turbo setup on the stock manifold looks great, like it was made to be mounted there from the factory. It's a clean setup that should be very durable.

Any timeline on when you will have it running again? As always, I am anxious to see your progress and results.

On a side note, the three M6 screws that attach the phaser to the cam seem a little on the small side. Hopefully they don't become an issue when people start putting big cams in these engines. Of course, I was never a fan of the single bolt setup on the earlier engines. The old three M8 bolt setup seemed quite reliable.

I'm hoping to have it running Thursday, I'm in the process of mounting it on the cradle this Wed morning but as usual there are little odds and ends that take extra time. I need to make a coolant return crossover pipe in addition to completing the exhaust so I might not get the engine back in the car until Thursday. As for the cam bolts I would hope the alignment pin offers a good bit of reinforcement to make shearing an unlikelyhood.

[Joseph Upson]

Time caught me again and I wound up having to leave a day ahead of schedule so I missed getting the car reassembled to the point of being able to at least hear how the engine sounds with the new exhaust and single turbo but I'm very close to that point at least. I added a bellows for the wastegate so that there is no difficulty with attaching it to the flanges. The exhaust is 3" into dual 2.25". It's a lot cleaner and roomy in the engine compartment and I now have plenty of room for the electric cruise control and water/meth injection unit.

The horsepower and torque numbers should be higher, I forgot to add an additional 200 or so pounds to the vehicle weight to account for me and the fuel when programming the GTech, not sure how much it would increase by. I entered the 2710 lb vehicle wt from my registration. I did a little reverse estimation with my turbofast program and came up with a wt corrected 217 hp, not much more. I couldn't estimate the torque. I'm very pleased with the reconstruction results and expect the performance to improve considerably at the same boost level. The main spark table is conservative in the boost range and I'm running on low octane fuel 88 octane, so there is plenty of room for performance improvement and I expect it once the engine is tuned properly. Hope I'm able to get back to it shortly to finish and test.