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Old 10-25-2017, 01:10 PM   #7
Fastest FWD GA
MilzyZ34's Avatar
AKA: Mike
Join Date: Aug 2003
Location: Dayton, OH
Age: 38
Posts: 949
Vehicle: 1999 Grand Am GT
MilzyZ34 Gettin' there
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I had to build the wiring harness from scratch. I built it to use the car's original fusebox, but with the G6 harness wired into it. The PCM is a out of a 2006 G6 GTP 6-speed. I had to get creative to bypass some of the can-bus stuff, but after some trial and error, I got it working.

Marc from TCE is still around. He had a bout with cancer a few years back, but kicked its butt, and has been pretty much healthy since then.

Due to the lack of availability of cam blanks, we did a regrind on the cam for this build.

Now for the end result of this huge potentially record-shattering project, as much as I hate not being able to build a car to it's full potential, I do have some excuses about the dyno results. I hope you guys can see past them to the true potential of this car, because this car is no slouch in any way.

First off, I should tell you guys about how the dyno day went. So I set aside the whole day because the instructions from the customer was to do all the break-in and tuning of this car on the dyno, nothing on the street because it actually arrived with no windshield so we couldn't even test-drive the car on the street. He didn't want to put a windshield in it right away because although the car came here freshly painted from the body shop, there were some chips and flaws that needed fixed, so as soon as we were done with the build, it was immediately getting shipped back to the body guys to fix the issues, which meant the windshield couldn't be in place. We had to bring plenty of fuel to dyno the whole day, including an ample supply of VP Racing MS109 race gas for the last part of the dyno where we would really light the wick on this baby, and see what it would do. The turbos we chose for the build are capable of 450hp each, and this combined with a forged bottom end begging for boost, and some killer heads and valvetrain, meant I had some high hopes for what this build would do.

So the way I usually do a typical 60 degree v6 dyno tuning session is like this: I do a basic turbo tune on the car, with super low timing (about 9 degrees at WOT), and a rich airfuel ratio of about 10.5-11.0:1, so it's super safe in case there are any issues. I have learned that it's also wise to bypass boost controllers when you first start tuning, because sometimes they fail, and when they do, they go infinite boost, where they build boost until either a charge pipe pops off, or the engine breaks something. So we started our runs at about 8-9 psi which is what the internal wastegates for the turbos were set at. So we start out on low timing, a rich AFR, and minimum boost, then we make some pulls dialing in the AFR. FOR a car getting shipped out of state, I will usually tune it to be around 11.25-11.5:1 so it's a little on the fat side in case fuel composition is a little different than it is here. Once I got the AFR about perfect, then I add some boost, and make sure the boost controller does what I want it to do. Then I bump the timing up to about 16 degrees on a stock compression engine on pump gas. Then I add some more boost. Depending on how strong the engine is, we'll typically end up somewhere between 16 and 26 lbs of boost. Then if we're doing race gas, I can add some more timing to add even more power.

So on this dyno day, we had a few more things to do as well. After the part-throttle tuning, and a few WOT passes, we would have to pull the car off the dyno, change the oil from the Royal Purple break-in oil we had in it to the Royal Purple oil the customer wanted, since the engine would then be broken in, and then put the car back on the dyno for more pulls. We also knew that we were going to peg the MAF on this car, which means to flow more air than the MAF can measure, so I had a plan to get around that as well just in case.

We started in the early afternoon, and didn't finish until after midnight.* First we proceeded to drive the car on the dyno going through the gears, and beginning to break the new engine in.* We monitored horsepower, torque, and boost through the dyno, and a whole range of parameters through the pcm such as RPM, vehicle speed, timing advance, knock retard, throttle position, O2 sensor values, injector duty cycle, long and short term fuel trims, coolant temp, intake temp, wideband data, and others.* After making a few passes terminating at around 4-5k rpm, it was evident that we would be running out of mass-air flow very soon, meaning that the Mass Air Flow (MAF) sensor would only read up to a frequency of about 11,500 Hz, and at 4000 rpm on low boost, we were already at about 9,000.* To alleviate this problem, which I foresaw being an issue, I brought a mini-AFC which allow you to scale back the measured frequency of the MAF to give it more range, because if you were to run out of range on the MAF, it no longer has the ability to add any more fuel, and will go lean and cause the engine to detonate.* So we installed the mini-AFC fairly quickly, and set it to the proper setting.* Then we made a couple more passes, then changed the oil from the Royal Purple 10w30 break-in oil to the Royal Purple 20w50.* For the beginning of the dyno tune, we bypassed the boost controller, to run the turbos off the wastegate or minimum boost setting.* Once we dialed in the air fuel ratio to a very very safe value of 11:1, and kept timing turned down to a miniscule 9 degrees to keep it very very safe, we then started dialing in the boost controller and adding boost.* We ran multiple runs at 9psi, 12 psi, even as high as 16psi.* We were getting close to the final part of the tuning when we noticed that the injector duty cycle was higher than we would want it to be, and combined with the symptom of the fluctuation of the fuel pressure at the higher rpm's at wide-open-throttle, I concluded that the cause was the fuel pump was not keeping up with the amount of fuel that the engine needed.* Normally with this sort of build, I would have recommended a Aeromotive fuel pump rather than the Walbro 255, but in this situation the customer was going to be out of contact while we were actually building the car, so we came to an agreement to follow the build sheet we had originally came up with this car with no additional changes, since we would not be able to get approval for any changes. So what I did to alleviate this fuel delivery problem was reduce the boost pressure to 9psi to make sure the fuel pump would have zero problem keeping up.* (This is the run on the dynosheet colored in pink.* It was ran in 3rd gear at 11:1 air fuel ratio with 9psi of boost).* Then I leaned out the air fuel ratio from 11.0:1 to 11.5:1, which put less demand on the fuel system.* (This is dyno run colored in green.* It was made in 3rd gear at 11.5:1 air fuel ratio at 9psi of boost).* Next I decided to test out our newly leaned ratio in 4th gear which is higher load, to make sure the fuel pump could still keep up with that as well.* (This is the run in red.* It was made in 4th gear on 9psi of boost, and with the same commanded air fuel ratio that resulted in a 11.5:1 ratio while in 3rd gear, achieved an actual ratio of 10.6 to 11.16, making it even safer).* So basically at the end of the day, we made 370whp at 9psi on very low timing (9-11 degrees during the run), equivalent to that of a stock turbocharged vehicle, and while this figure may be lower than we ultimately wanted to achieve by adding more boost and more timing, the result is a very powerful, and extremely safe setup that still more than tripled the original engine's output. My recommendations would be to use the Aeromotive fuel pump, along with some larger injectors of around 80lb/hr instead of the 57's it has now, and to install a "fuel pump hotwire kit" to increase the gauge of wire used to feed the fuel pump, along with another new fuel filter, and then calibrate it for the new injector size, and take it back to the dyno to turn up the boost and see what it would do.* I made these recommendations to the customer, and let him know if he wanted to bring it back here after the body work is done, I would definitely like to see what it would do turned up.

Here is the dyno sheet for the last three passes

The last run is offset in the RPM because the dyno's pick-up for the tach signal developed a bad connection, so we switched to a roller tach (using a tach based off the roller rpm, which is proportional to the speed of the tires. We had this value dialed in very close for 3rd gear because most of our runs were made in 3rd gear so there would be less load, so we wouldn't have to take as many breaks to keep the car cool. The last run was made in 4th gear, and we didn't have the calibration for the tach dialed in quite so good, so it looks like it's off about 300 rpm

So there you have it, the biggest 60 degree V6 build I've ever done, and we had to turn it way down just because we didn't have a large enough fuel pump. Still though, 370 whp with it all the way turned down isn't bad at all. I would love to see what it would do on 26-30psi and 16-20 degrees of timing!
1999 Z34 - Was a Stage 3 3800 Supercharged, but not fast enough so I have some new plans for her.
1999 Grand Am GT Race Car - 12.1 sec ET, STOCK motor, 10 psi
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