Low dyno
Thread Starter
11 Second Club
iTrader: (20)
Joined: Jul 2002
Posts: 1,988
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From: Jonesboro, Ga
Low dyno I have the mods in the sig, except I was running open
headers I dynod 355rwhp, I was expecting 370rwhp+.. I
am still running the LS1 intake. The car is not tuned.
My question is:
A) I forgot to put an o2 sim on, could this contribute to a
low dyno number?
B) The car was open headers, is it possible that the car
was picking up false knock from the loudness? If so what
can I do to keep this from happening?
C) The car had less than an 1/8th of a tank of gas when
I dynod. I remember hearing that if you were really low on
gas the car will retard timing. Is this true? Everybody I
asked said they hadn't heard that.
D) The car doesn't noticably smoke, and doesn't have
a lick of trouble idling with the 112lsa 224/224 even
with the TB not drilled. Because of this, I was thinking the
tune probably isn't that bad. Do you think that its my tune
that is leaving me 10-20rwhp short or other factors above?
Also, what is the cheapest method for me to get a tune,
as I don't want to spend a fortune on the cam only setup
when I will be getting nitrous and heads in the next few
months.
Thanks,
headers I dynod 355rwhp, I was expecting 370rwhp+.. I
am still running the LS1 intake. The car is not tuned.
My question is:
A) I forgot to put an o2 sim on, could this contribute to a
low dyno number?
B) The car was open headers, is it possible that the car
was picking up false knock from the loudness? If so what
can I do to keep this from happening?
C) The car had less than an 1/8th of a tank of gas when
I dynod. I remember hearing that if you were really low on
gas the car will retard timing. Is this true? Everybody I
asked said they hadn't heard that.
D) The car doesn't noticably smoke, and doesn't have
a lick of trouble idling with the 112lsa 224/224 even
with the TB not drilled. Because of this, I was thinking the
tune probably isn't that bad. Do you think that its my tune
that is leaving me 10-20rwhp short or other factors above?
Also, what is the cheapest method for me to get a tune,
as I don't want to spend a fortune on the cam only setup
when I will be getting nitrous and heads in the next few
months.
Thanks,
Thread Starter
11 Second Club
iTrader: (20)
Joined: Jul 2002
Posts: 1,988
Likes: 0
From: Jonesboro, Ga
Jrp,
This dyno did not have the equipment in order to monitor
my a/f ratio. However, I can post a graph up tomorrow.
The car made 355.3 hp and 355.1 tq on the 3rd run out
of 3. Torque was 320 at 2500, and more or less was
straight across all the way to its peak of 350 at 4800ish.
Horsepower had a steady accelerating curve and
peak horsepower was around 5700rpm. From 5700rpm-
6500rpm the car drops to 340rwhp and stays even all
the way across. Power drops off at 6600. I have been
shifting it at 6500 BTW. I thought the peak horsepower
was kind of at a low rpm. I don't know what this means.
The graph to me, doesn't indicate any valve float.
I'll be getting a cable to autotap it and see what I can
find out about knock, etc. However, the local dyno won't
be capable of doing my a/f til March. This is very
unfortunate!
PS. It was a dynojet, not a mustang. I believe maybe it
said 248?? So its not a stingy dyno.
Thanks,
This dyno did not have the equipment in order to monitor
my a/f ratio. However, I can post a graph up tomorrow.
The car made 355.3 hp and 355.1 tq on the 3rd run out
of 3. Torque was 320 at 2500, and more or less was
straight across all the way to its peak of 350 at 4800ish.
Horsepower had a steady accelerating curve and
peak horsepower was around 5700rpm. From 5700rpm-
6500rpm the car drops to 340rwhp and stays even all
the way across. Power drops off at 6600. I have been
shifting it at 6500 BTW. I thought the peak horsepower
was kind of at a low rpm. I don't know what this means.
The graph to me, doesn't indicate any valve float.
I'll be getting a cable to autotap it and see what I can
find out about knock, etc. However, the local dyno won't
be capable of doing my a/f til March. This is very
unfortunate!
PS. It was a dynojet, not a mustang. I believe maybe it
said 248?? So its not a stingy dyno.
Thanks,
definately atap it and get as much info as you can from there. keep in mind you have a 12 bolt and 4.10's and that'll rob you of dyno hp. you also said you ran open headers; what do you mean by that? a cutout somewhere or just open air straight off the collector?
