[Z06] Heads and Black Widow cam are installed. A few issues.
03-28-2013, 05:58 PM
#1
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Heads and Black Widow cam are installed. A few issues.
Mods are as follows.
PRC 265 port work to my stock castings with new stainless exhaust valves and bronze guides. Milled .020 with new gm gaskets.
Black Widow cam with dual valve springs.
7.750 Pushrods. (Checked with a length checker)
Katech C5r timing chain.
MSD wires with stock plugs.
Airaid intake.
JBA 1 7/8" Headers with catted x-pipe.
Tune.
The JBA headers are a little off on fitment. When the engine torques the passenger side collector hits the heat shield and the X-pipe will not hook up to the mufflers without the tips being tilted and not even. I do not recommend these.
The cam idles and drives good considering the size. It has some manageable surging, especially around 1500 or so but you can cruise around at 1100 just fine. It does hunt for idle a bit when you first start it and it diesels a little when you kill it.
Now for the big issue. My car made 485/450SAE with nothing more than the AirAid and a tune. It now makes 539/461SAE on the same dyno. The car runs great it just seems to be missing quite a bit of HP and especially TQ. We were thinking that maybe the cats were causing too big of a restriction? Anyone have any ideas?
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PRC 265 port work to my stock castings with new stainless exhaust valves and bronze guides. Milled .020 with new gm gaskets.
Black Widow cam with dual valve springs.
7.750 Pushrods. (Checked with a length checker)
Katech C5r timing chain.
MSD wires with stock plugs.
Airaid intake.
JBA 1 7/8" Headers with catted x-pipe.
Tune.
The JBA headers are a little off on fitment. When the engine torques the passenger side collector hits the heat shield and the X-pipe will not hook up to the mufflers without the tips being tilted and not even. I do not recommend these.
The cam idles and drives good considering the size. It has some manageable surging, especially around 1500 or so but you can cruise around at 1100 just fine. It does hunt for idle a bit when you first start it and it diesels a little when you kill it.
Now for the big issue. My car made 485/450SAE with nothing more than the AirAid and a tune. It now makes 539/461SAE on the same dyno. The car runs great it just seems to be missing quite a bit of HP and especially TQ. We were thinking that maybe the cats were causing too big of a restriction? Anyone have any ideas?
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Last edited by nyerby; 03-28-2013 at 06:20 PM.
03-28-2013, 06:31 PM
#4
Burning Brakes
Hmmm... I had trouble holding timing, with TR55's, so when I swapped to TR7ix,I was able to add in 2-3 degrees which made a significant difference.
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
03-28-2013, 06:43 PM
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Hmmm... I had trouble holding timing, with TR55's, so when I swapped to TR7ix,I was able to add in 2-3 degrees which made a significant difference.
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
03-28-2013, 06:46 PM
#6
Then we have some kind of major air/fuel glitch at 5900 RPM on the 2nd dyno run. Did the probe fall out of the tailpipe?
03-28-2013, 06:50 PM
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There are serious problems with that baseline dyno graph, starting at about 5000 RPM and getting really bad at about 5700 RPM. I'd be shocked if they dyno operator did not mention it at the time.
Then we have some kind of major air/fuel glitch at 5900 RPM on the 2nd dyno run. Did the probe fall out of the tailpipe?
Then we have some kind of major air/fuel glitch at 5900 RPM on the 2nd dyno run. Did the probe fall out of the tailpipe?
03-28-2013, 06:53 PM
#8
Hmmm... I had trouble holding timing, with TR55's, so when I swapped to TR7ix,I was able to add in 2-3 degrees which made a significant difference.
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
What timing advance are you running? Any logs?
Perhaps bad fuel?
From your descriptions of the characteristics, I would be suspect of the tune. As it should not diesel on shutown, period. And if it is hunting for idle, it is indicative of the tune not being dialed in.
Now none of the above attributes would affect power output, it does place a question on the rest of the calibration.
My bet is that the tune is NOT where it should be...
Some people tune that cam better than others.I'd also be looking to get those headers off and put a better set on it ASAP.
03-28-2013, 08:03 PM
#9
Race Director
From what you're saying about the behavior of the car , surging , idle hunt , diesel on shut off . The tune is off , or you've got a bad wire , header leak even . But my guess is the tune . As you said the power is way off
03-28-2013, 08:12 PM
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I will check the plugs and wires. If someone that knows what to look at and wants to volunteer to look at the tune I can get the logs and the hpt file.
03-28-2013, 08:22 PM
#11
Burning Brakes
If you are willing to post up the tune, that would eliminate a bunch of speculation.
Tuning for drivability is an artform, and takes a considerable amount of experience with the combo in question, not just your's but any combo. WOT tuning is as simple as it gets, and something seems amiss with your tune.
Without more details it is just wild speculation. IF you are not comfortable with posting up the tune, you can pm it to me.
But a datalog would go a long, long way to justifying the tune. A dyno is just a tool, and not the be all end all. IF your logs show a happy ecm, then all is good.
If you havent already, try and log a WOT pull in as high a gear as you can, and if it is in a gear less than 4th, then most preferably uphill, so as to load the engine sufficiently.
Tuning for drivability is an artform, and takes a considerable amount of experience with the combo in question, not just your's but any combo. WOT tuning is as simple as it gets, and something seems amiss with your tune.
Without more details it is just wild speculation. IF you are not comfortable with posting up the tune, you can pm it to me.
But a datalog would go a long, long way to justifying the tune. A dyno is just a tool, and not the be all end all. IF your logs show a happy ecm, then all is good.
If you havent already, try and log a WOT pull in as high a gear as you can, and if it is in a gear less than 4th, then most preferably uphill, so as to load the engine sufficiently.
03-28-2013, 11:46 PM
#13
Safety Car
Did you call Carlos/Myhardtop about the issues your having? Give him a call he is an excellent tuner
03-29-2013, 02:00 AM
#15
Send your file to Carlos
I also changed the plugs in my car with my gt-20 cam went from the tr-6 to the platinum tr6ix I feel like the car gained about 10hp just from that and yes the plugs are better I would change them.... Carlos should chime in give him a call
03-29-2013, 09:54 AM
#16
Burning Brakes
OP was able to forward me the dyno log, and the car had major knock retard from 5700 - 6300, to the tune of 4.6 degrees! That will kill power in a hurry. The rest of the run was ok, but the timing was definitely aggressive for pump gas.
03-29-2013, 09:57 AM
#17
Burning Brakes
05-18-2013, 01:33 PM
#19
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UPDATE: Thanks to Maryland Speed and their great customer service I was able to get rid of the crap JBA headers and move up to some Kooks 1 7/8" with a catted X-pipe. I also went to a colder plug. After logging a few WOT pulls with the wideband my A/F is sitting at 10.9-11.3:1. It looks like the cats on the JBAs were very restrictive... I will get it re-tuned Monday or Tuesday and see what happens.
Last edited by nyerby; 05-18-2013 at 01:36 PM.
05-18-2013, 02:12 PM
#20
Le Mans Master
A very popular vendor on the Ford site SVTperformance just recently posted......he dumped the entire JBA line - too many issues on a regular basis, including fitment
Last edited by RedZ4me; 05-18-2013 at 03:28 PM.
