Well the results are in and are not good. Something is wrong with the car somewhere and we have no idea where. It is not loading properly on the dyno. A 99GT with a KB on the same dyno as me put down 130% for load. My car could only see 100%. Torque curve is more like a centri blower not a PD blower. It made OK power on the one run my tuner actually made. He made one full throttle pass and made 396HP and 404tq at the wheels with 7#'s of boost and that was without tuning, just cleaned up the air fuel a bit, he said timimg is way off too, with the amount of timing he's pulled he said the car should be detonating like crazy but not a peep. We did every test imaginable, compression tests, blow by tests, battery voltage, MAF, the only thing funny is O2 sensor readings, there is something screwy there. I'm thinking it is an intake manifold gasket leak personally. Could be timing chain slip too. I'm gonna take the whole thing apart when I get her home next week and see what I can find. For now I guess i can handle what it has, hope to see more when we can actually tune the car properly though. Gotta find this gremlin first. Theres the scoop, not what I wanted to here but I thought I'd at least update you guys.
Dyno numbers and car update
- Thread starter TweekedGT
- Start date
stangGT97
New Member
well if a gasket was leaking, your car wouldnt pass a vacuum test. Is it possible your computer is fried? About the O2s, I believe that they have no bearing on your WOT tuning as your computer goes into an open loop, but they would have a huge impact on your part throttle driving. Is your maf calibrated for 60lb injectors? I don't know what to tell you man! Your engine is pretty much brand new, this crap shouldn't be happening. Keep us posted
edit - I remember a while back hotmustang331 was talking about his cam install and the tuning for it. Tim from MPH said it is possible to have your timing be off enough that you could have an exaust valve still part way open during the compression stroke, which would kill your fuel economy and power. I would check the cam install, you might be dumping fuel out the tail pipes and completely demolishing your O2 sensors.
and for the record, Peter Griffin > all
edit - I remember a while back hotmustang331 was talking about his cam install and the tuning for it. Tim from MPH said it is possible to have your timing be off enough that you could have an exaust valve still part way open during the compression stroke, which would kill your fuel economy and power. I would check the cam install, you might be dumping fuel out the tail pipes and completely demolishing your O2 sensors.
and for the record, Peter Griffin > all
jstreet0204
Active Member
I'm not sure who your tuner is but hopefully he already knows these things, but here are a few things that need to be done in the tune in your case that will effect load.
1. The displacement scalar needs to be changed from 280.736 to what ever your stroker works out to.
2. All of the load dependent tables need to be normalized to allow for the load going over 100%
3. Make sure you have the CORRECT injector slopes, fuel breakpoint, and injector to voltage offset, for the injectors you have. Different brands require different settings, so he can't go just by the size.
4. Make sure the documented MAF curve is used first before fine tuning it.
It may be a mechanical problem, and have nothing to do with the tune, but if these things aren't correct in the tune, you may never know so I thought I'd just mention them.
Also, try posting your problem over here. http://eectuning.org/forums/
Somebody over there will likely know what is wrong.
1. The displacement scalar needs to be changed from 280.736 to what ever your stroker works out to.
2. All of the load dependent tables need to be normalized to allow for the load going over 100%
3. Make sure you have the CORRECT injector slopes, fuel breakpoint, and injector to voltage offset, for the injectors you have. Different brands require different settings, so he can't go just by the size.
4. Make sure the documented MAF curve is used first before fine tuning it.
It may be a mechanical problem, and have nothing to do with the tune, but if these things aren't correct in the tune, you may never know so I thought I'd just mention them.
Also, try posting your problem over here. http://eectuning.org/forums/
Somebody over there will likely know what is wrong.
stangGT97
New Member
That is one of the possibilities we are looking at, the car does respond to tuning though.stangGT97 said:
stangGT97 said:
This is where we actually think we may have problems. Here's the reasoning: The car is down on power, it is low on compression (we think-we are getting 114-120 across the board for cylinder pressure at cranking compression), and it is running rich. All of those things relate majorly to cam timing. If we were off 1 tooth that could equal 5degrees of timimg which could cause all of this. I'm going to pop the valve covers and timing cover off and see where we are at. The only problem is that I did run the car N/A before I put the blower on and it seemed fine. I thought I should be seeing more power than i actually was though, i was running the same track times as i was with my 4.6. Maybe by having the supercharger on it just amplified the effects to a more noticeable level?? Does that make sense? i guess it's a place to start
.
read jstreets post.. you may want to try a different tuner. I highly doubt you have one of the cams off a tooth. You would have noticed that when the car was N/A
hotmustang331
Active Member
TweekedGT said:That is one of the possibilities we are looking at, the car does respond to tuning though.
This is where we actually think we may have problems. Here's the reasoning: The car is down on power, it is low on compression (we think-we are getting 114-120 across the board for cylinder pressure at cranking compression), and it is running rich. All of those things relate majorly to cam timing. If we were off 1 tooth that could equal 5degrees of timimg which could cause all of this. I'm going to pop the valve covers and timing cover off and see where we are at. The only problem is that I did run the car N/A before I put the blower on and it seemed fine. I thought I should be seeing more power than i actually was though, i was running the same track times as i was with my 4.6. Maybe by having the supercharger on it just amplified the effects to a more noticeable level?? Does that make sense? i guess it's a place to start
Heh...try about 17*s. The guys on MD said that 1 tooth is worth around 17*s. That would explain your power being all highend...retarding cam timing premotes upper RPM power, but costs mid range. In your case if this is true, it would jack everything lol. If you were advanced you would have PTV.
Good luck man
And thats still some good power!jstreet0204 said:
He's been tuning for 10 years and went through a whole bunch of tuning jargen with me that was over my head. He did increase the displacement to a 302 which is what my stroker is. I don't know about your second point, I know he said he could tune the car and increase load by adding displacement but that would falsefy the tune. He was worried that whatever is "wrong", if it were to fix itself the car would pretty much explode because there is so much timing in it. He said we should be hearing massive detonation with the amount of timing he has added but there is nothing. He had to take out 35% fuel just to get the car to run with an A/F of 11.7. I'll try the sight you suggested. Are there any other mechanical issues that could cause such a massive rich condition?? Cam problems or poor timing is all i can think of other than a vacuum leak which doesn't seem to be the case according to my boost/vac gauge, it is running 15-20 PSI at idle.
hotmustang331 said:Heh...try about 17*s. The guys on MD said that 1 tooth is worth around 17*s. That would explain your power being all highend...retarding cam timing premotes upper RPM power, but costs mid range. In your case if this is true, it would jack everything lol. If you were advanced you would have PTV.
Good luck man
Did you have to degree in your cams?? If so how do you degree in a SOHC cam?? Something just aint right here.
haha welcome to my last 2 months. Are your 02's not switching properly... and then pulling fuel when your already lean??? Thats what has been up with my car. We have it narrowed down abit but I havent been to the shop in the last few days So I dont know the latest. It is an eletrical issue. Something is sending false readings but we have changed everything you would normally think of. 02's, PCM, Chip, yada yada.
If I find out something tomorrow when I swing by I'll let ya know. maybe it will help you.
If I find out something tomorrow when I swing by I'll let ya know. maybe it will help you.
01Steeda said:haha welcome to my last 2 months. Are your 02's not switching properly... and then pulling fuel when your already lean??? Thats what has been up with my car. We have it narrowed down abit but I havent been to the shop in the last few days So I dont know the latest. It is an eletrical issue. Something is sending false readings but we have changed everything you would normally think of. 02's, PCM, Chip, yada yada.
If I find out something tomorrow when I swing by I'll let ya know. maybe it will help you.
I'm not getting any voltage out of my front O2's at all. I don't know if it's electrical or ECU or what. I've tried to find an ecu for a 96 or 97 GT but it's impossible. If you do find anything out let me know, it may be a place to start looking
. Thanks Man!
stangGT97
New Member
TweekedGT said:I'm not getting any voltage out of my front O2's at all. I don't know if it's electrical or ECU or what. I've tried to find an ecu for a 96 or 97 GT but it's impossible. If you do find anything out let me know, it may be a place to start looking
hey, I looked around and found a place that sells replacement computers for your 96. It's southwest ford in TX, I deal with them a lot, they're a great company. Here's the link
computer
I hope that helps
OK, just talked to my mechanic. All my electrics chck out. The only thing about the elec. that still concerns him is that the 0'2's arent switchiing like they should so he is still working on that. He said the vacuum my motor pulls looks low formy setup and he is gonna look more into that as well.
so basically nothin yet
I'll keep ya posted... u do the same pls
so basically nothin yet
I'll keep ya posted... u do the same pls
stangGT97
New Member
jstreet0204
Active Member
TweekedGT said:
Basically the second point about normalizing the tables just means that several tables have one axis that is a load value. In the stock configuration, these values go from 0 to 100% load. there are funnctions that will change the values to go up to say 150%. I wasn't really saying the tune was the problem, I just wanted to point out a few things that if were missed in the tune, might prevent you from finding the actual cause. The guys on the other board may be able to help you track down another computer as well. Good luck with it.
hotmustang331
Active Member
We didnt degree the cams in....but I do know that they require aftermarket cam gears...otherwise all you can do is install the cams straight up
hotmustang331 said:We didnt degree the cams in....but I do know that they require aftermarket cam gears...otherwise all you can do is install the cams straight up
I really think that this is where my problem lies. I think I need to degree these cams. It makes sense that somehow i am getting valves open on the compression stroke. It would cause all three of the things that are looking funny with the car. Rich condition, down on compression, down on power. I'm gonna start with degreeing the cams and go from there. Now i just have to order a cam degree kit and see what happens. Thanks for your help you guys. It's nice just to "talk" about it and get ideas where to look. :SNSign:
. Sometimes you just need that little insight that clicks.
I picked up a set of Fidanza adj cam gears from Livernois Motorsports...cost mr like $250 but i figure i spent so much on everything else why not squeeze every ounce of HP out of this thing not to mention getting them degreed in perfect will make it run its best.TweekedGT said:I really think that this is where my problem lies. I think I need to degree these cams. It makes sense that somehow i am getting valves open on the compression stroke. It would cause all three of the things that are looking funny with the car. Rich condition, down on compression, down on power. I'm gonna start with degreeing the cams and go from there. Now i just have to order a cam degree kit and see what happens. Thanks for your help you guys. It's nice just to "talk" about it and get ideas where to look. :SNSign:
Sorry your having these issues! Hopefully you get everything straight soon. Winter is coming
