3900 swap into Fiero

[Joseph Upson]

I'm gonna guess here and say the 3900 O2 will not be compatible. Superdave was running the LX9 3500 O2 for a while but it never acted right, he went to the older style 3400/3100 heated ones and it works much better. They must have changed something in them.

Did you try to contact Mark about TunerPro? Or is it maybe a bug in the bin mask file thingy?

EDIT: Are you running the latest version?

v4.14.0381 (3/16/0

TunerPro Free & TunerPro RT

• Fixed Internet update server connection issue
• Fixed issue with Function item editor, where axis limits weren't being stored correctly

Actually it appears the sensor does work. I didn't have the ground wire connected and when I supplied it with power the ecm went into closed loop and held it for about 95% of the data log which was about 3 minutes long. A code 45 set for rich condition and the integrator bottomed out several times at 76. The BLM didn't move much but then that may have had something to do with the rpm level which was mostly above 2K.

I checked Tunerpro updates today and did not see an 08 correction. I do have 4.14 something.

I'm having a bit of trouble with the alternator. I installed a little 5v regulator today and it appeared the voltage went up a bit more over 13v but later on it started registering in the 12 v range on the datalog. I'm not sure if I damaged the alternator with the 12v feed or if the regulator is not carrying enough amperage which I doubt. I'll have to take it and have the system checked.

Mean while, I rigged the oil filter relocation adaptor by putting a layer of aluminum inside the threaded hole to tighten it on the nipple since GM decided to throw a curve and put an odd thread pattern on it that doesn't fit the available adaptors properly. As you can see in the picture it blue it off while revving around 6k and it's a blessing that it happened in the drive way and that the car didn't go up in flames because the oil doused one of the glasspacks. I'll check into have an extra adaptor tapped with the proper threads in the morning. That incident suggests my oil pressure gauge is way off and that the 80 psi I saw at one point is actually correct and the low 40 and below reading is the result of a bad sensor that's fluctuating as it has done for a while now, at least I hope.

STILL COULD USE SOME INPUT ON THE ALTERNATOR ISSUE.

[Joseph Upson]

That hot link was an accident, the link was in my clip board where I thought I was linking to the video.

http://videos.streetfire.net/video/Fiero-3900-Turbo_154625.htm

[ForcedFirebird]

I love the idle. What cam specs did you choose, and what RPM is idle?

Can't wait to see it in action!

EDIT: Watched the video again, and just before the baby blip, it looks like 550rpm?

[Joseph Upson]

I love the idle. What cam specs did you choose, and what RPM is idle?

Can't wait to see it in action!

EDIT: Watched the video again, and just before the baby blip, it looks like 550rpm?

Yeah the idle drops from time to time and I believe in the video during the tale pipe shot it might have been as low as 400, the dual mass flywheel probably has a lot to do with that and I believe the Harley Davidson engines have a heavy flywheel that helps them keep chopping at very low idle. My idle is actually set at around 950 but tuning and possibly the IAC passage has an effect on it. The throttlebody adaptor plate from the store had to be modified because it has no passage for incoming IAC air so it's possible I may need to make the passage larger though I doubt it.

I attached a datalog sample from Tunerpro in the tuning thread. I will have to hot link my converter directly to the battery since the circuitry built into it shuts it down if it doesn't see the battery voltage it wants. My laptop battery is shot and the computer will not run more than about a minute without auxillary power so hopefully the shift cable will arrive by 1pm and I can install it and test drive the car to get some on road data for tuning after I bypass the cigarette lighter and plug into the battery.

[Joseph Upson]

I did a moderate test drive today since the water injection kit is not installed I didn't want to push it to hard along with the need for more tuning. At the moment it's more of a top end ride but hopefully tunning and smaller turbine housings will restore some bottom end grunt. If not, at some point I'll install the stock camshaft and incorporate the VVT in a basic on off function.

http://videos.streetfire.net/video/Fiero-3900-Road-test-for-tune-status_159781.htm

[IsaacHayes]

Can the VVT work on/off with a simple switch/relay ? Or does it need PWM? Is it just like +12 or +5v and it works?

[ForcedFirebird]

I didn't realize you are non-intercooled.

Sounds good, can't wait to see some wider throttle

[merlot566jka]

Can the VVT work on/off with a simple switch/relay ? Or does it need PWM? Is it just like +12 or +5v and it works?

i think it works on oil pressure, and i think its progressive. dont know what it takes or how it works. id be interested in knowing though

[Joseph Upson]

Can the VVT work on/off with a simple switch/relay ? Or does it need PWM? Is it just like +12 or +5v and it works?

PWM would be proper for it but without the OE PCM to operate it on/off would serve the same purpose with less resolution in between since instead of a gradual change in cam position over the rpm it would just switch from low range rpm to high when retarded.

It would have to do this at the same rpm point everytime otherwise it would throw the tune off since the older ecm can't correct for VE in the event phasing stops working and the cam remains advanced at a point where it's supposed to be retarded at say the midway point of the rpm range, VE above that point would be very poor if the cam did not retard to increase upper rpm efficiency to match what it was initially tuned for when working as intended. In stock form if the VVT stopped working hp output would be greatly reduced.

I didn't have the room I thought I would for the intercooler and water injection is just as good so I took that route.

[Joseph Upson]

The last test drive was much better and still suggestive of the spark table needing to be a little more aggressive, I added about 2 more degrees but didn't datalog to check for detonation this time since the 93 should be good enough for 7psi. Running on 93 octane may have a lot more to do with it at the moment not having detonation. It barely saw 7psi under full boost so hopefully it's efficient enough to run 7psi on 87 octane which will leave a lot of room for higher boost eventually 12 psi which should really make the 1-2 shift special.

So far that test drive was with no intercooling or water injection, and a maximum boost of barely 7 psi actually less considering the datalog did not show boost reach 150 kpa. The smaller turbine housings, water injection, increased boost and tuning should put it about where I would like to have it.

I have to take a moment to bring attention to the fact that the stock compression for this engine is 9.8:1. There have been many debates and arguments about needing to run low compression with turbos here in the past. You should run as high a compression as the boost level you intend to run will allow. In my case once water injection is installed 14 psi with pump gas should not be a problem.

There is also a possibility the oil jets for the pistons are helping also because oil temps are running on what to me is the high side at just over 220 suggesting additional heat being absorbed from the pistons, at some point I'll get more air to the oil cooler.

http://videos.streetfire.net/video/3900-V6-Turbo-Fiero-tunning-runs_159990.htm

[merlot566jka]

more timing? is the tgp code conservitive for the more efficent 3900?

i went through high oil temps on my vette. i never got a good fix, but i ran around 275* at the track. intown was around 255. i like cadillac's 3.6, it has a decent sized oil cooler that sits in the valley of the engine and is cooled by coolant.
maybe you will need something more agressive, like a thermostaticly contolled oil cooiling setup, and maybe even a water to oil heat exchanger.

on the copression vs boost...yeah, i dont buy into the common misconception. i have read many turbo books recently and the good information from them says to take advantage of your compression and use proper intercooling to achive high boost on a high compression engine. it said dont fall into the trap that some kit makers suggest, lowering the compression to see more boost and lower egts. what would the point be to run high boost on an engine that doesnt make the most of it. most books go further than what ive said, but thats all i have retained.

and get out and strech those 'long legs'! you are going to need a drag strip to tune that thing at any gear above 2nd!

[Joseph Upson]

more timing? is the tgp code conservitive for the more efficent 3900?

i went through high oil temps on my vette. i never got a good fix, but i ran around 275* at the track. intown was around 255. i like cadillac's 3.6, it has a decent sized oil cooler that sits in the valley of the engine and is cooled by coolant.
maybe you will need something more agressive, like a thermostaticly contolled oil cooiling setup, and maybe even a water to oil heat exchanger.

on the copression vs boost...yeah, i dont buy into the common misconception. i have read many turbo books recently and the good information from them says to take advantage of your compression and use proper intercooling to achive high boost on a high compression engine. it said dont fall into the trap that some kit makers suggest, lowering the compression to see more boost and lower egts. what would the point be to run high boost on an engine that doesnt make the most of it. most books go further than what ive said, but thats all i have retained.

and get out and strech those 'long legs'! you are going to need a drag strip to tune that thing at any gear above 2nd!

So far it appears the stock TGP code can be pumped up a little, it was also designed for an automatic and there was an area in the table with considerable timing reduction and I'm sure gear ratios had something to do with that.

I believe the oil temps are kind of high because of the heat it absorbs from the pistons, the cooler is not in the most optimal location and it is getting some heat from one of the mufflers which will get a good bit more heat wrap than the one layer it has to eliminate that. Later I'll invest in some mufflers that will fit in the tail pipe location so I'll have room to add a fan to the cooler. There is an additional cooler that uses coolant at the oil filter so if I can get oil temps down around 175 that will be a big plus.

And second gear would definately need to be on the hwy because it really pulls as the rpm climbs. I'll have the smaller turbine housings on tomorrow to see if that adds to the bottom end and hopefully the water injection kit will be installed also. I'll leave it at its current boost level until the tune is in good shape then I'll turn it up.

[IsaacHayes]

The TGP code is conservative for shitty gas in high hot heat climates so that the engine would never blow up probably. Plus the 3900 flows better so you are able to run more before ping under boost anyways.

[merlot566jka]

i thought oil temps below 200 were bad, as in they cant remove the water from the oil. and it keeps the viscocity too high and the detergents arent going to work at low temps.

at least thats what the navy told me. but they also let people who have shit for brains dictate what i do. so who knows if thats legit.


do you have a manifold temp sensor to show what kind of heat is in there? may help pick the turbines for higher engine speeds, by seeing if the turbo is out of its range and blowing hot air instead of making boost....

[Joseph Upson]

i thought oil temps below 200 were bad, as in they cant remove the water from the oil. and it keeps the viscocity too high and the detergents arent going to work at low temps.

at least thats what the navy told me. but they also let people who have shit for brains dictate what i do. so who knows if thats legit.


do you have a manifold temp sensor to show what kind of heat is in there? may help pick the turbines for higher engine speeds, by seeing if the turbo is out of its range and blowing hot air instead of making boost....

I understood 180 to be the low limit and considering the oil jets function I would want to be on the low side for the greatest amount of heat removal from the pistons. Clearing out condensation if any develops should be taken care of once the PCV vent is connected ahead of the turbo to suck a fresh charge of air into the crankcase and clear out bad air.

The MAT sensor reading is what two other members in a thread under computer related are helping me with, I have registered a high of 104 units, not sure if that needs to be converted or if it's degrees or celsius, most certainly celsius if the value is a correct output reading. I ran compressor maps and I should be in the 74% efficiency range around 11psi boost, but since I'm only mustering 6psi the map shows 65% which is still okay and definately a non issue when the water injection is added.

I plan to move up to TO4E 57 trim compressors later on, it will only provide 78% peak efficiency which is only four % more than what I currently am capable of so I may not bother.