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Discussion Starter #1
I went to dyno my Cobra today with a JMS chip. I did 2 base runs with the chip off, 2 runs with the first tune, 3 runs with the second tune, and 3 runs with the third.

The base pulls started off good with a 309.2 rwhp and a 299.7 rw/tq.

Once I turned on the first tune there wasn't much of an increase over the base with a 309.5 rwhp and a 301.4 rw/tq, I was not pleased. Tried it again, barely anything.

Then I tried the second tune, the power went up to 312.1 rwhp and 305 rw/tq. which was a 2.9 rwhp and a 5.3 rw/tq. increase. The other 2 were about the same.

Finally, I tried the third tune. The first pull was a 311.2 rwhp and a 302.6 rw/tq. which was a 0.9 hp and a 2.4 tq. decrease, I was kinda dissapointed. Tried it again, a little increase but not much. Finally, the last run was a good one. I was quite pleased

Here's the link: http://www.svtperformance.com/forums/showthread.php?s=&threadid=28034
 

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Tim,

Not to rain on your parade, but the chip did not do much for your car, if anything at all. Our cars tend to produce better dyno figures as the cars' engine and driveline fluids warm up.

There may be increases of up to 10 rwHP and rwTQ after a series of consecutive dyno pulls, regardless of whether or not chip settings have been changed. The fact that your first two pulls with the most aggressive chip setting netted you very little in comparison to the 3rd pull is a testament to this.
 

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Another mail order chip, I presume?
 

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Discussion Starter #4
Jahel'98COBRA

The chip did give me more power all the way through the rpm band, and it did help the dip that I have between 5000 and 5500. I got a nice gain in power between the 5000 to 6000 rpm range,so in closing the chip did help me out with I feel some more room for more tuning.

Tim
 

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My car has been tuned on a lot, and IMHO how much power you make does not tell you much about how good the tune is. You can usually (repeat: usually not always) make more power running leaner with more timing. Question is how much more power can a tuner pull from an engine, in his quest to out do some other tuner, before he gives you a tune that destroys the engine when something unforsee occurs?

Fortunately, JMS has a great reputation for conservative tuning. Based on your post, it sounds like that is what you got. Enjoy!
 

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I agree with Ralph. In addition too many people focus on peak rwhp and peak torque. Those are nice for bragging rights, but the real story is the avg rwhp and torque. You are at your peak numbers for a instant, but the average wins the race.

To really know what you gained, build a spreadsheet with rwhp and torque number columns for each 100 rpm. Add each dyno run done and then subtract each run's columns to see how much you gained or lost.

My last dyno run netted me not increase in rwhp, though torque was significantly higher. But if you compare my previous run, my number went you tremendously in every rpm range. As much as 40 rwhp. Which car is faster? The answer is simple.

Chris
 

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Hey Chris, that's great to advise everyone to look at the WHOLE spectrum instead of the peak only. Plotting the dyno readouts at each 100 rpm and comparing them certainly tells the real story. Very important point, Chris!
 

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Those are decent results with good power across the board. Some guys get a little more and some may get less. Expectations of numbers greater than yours with those mods is not realistic as every car is different as to what tuning parameters it will or will not accept. It appears you made more than 1 run per tune to back up data which was smart.

Now you also have data for fine tuning adjustments up the road that you can work with if needed. As far as being "mail order" who frkn cares. There are folks on this board that can't even plug in a chip without help and now you have info for finer tuning if need be. Congrats on moving forward in a positive direction with your car.
JMO
Shawn
 

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That is great advise Chris and exactly what I do. Here is a good example of one of my mods You should see what the spreadsheet looks like graphed out with 40+ dynos at the same time!!!! Sheesh!!! ;)

Chris98vobra said:
To really know what you gained, build a spreadsheet with rwhp and torque number columns for each 100 rpm. Add each dyno run done and then subtract each run's columns to see how much you gained or lost.
 

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Discussion Starter #11
Chris98vobra said:
I agree with Ralph. In addition too many people focus on peak rwhp and peak torque. Those are nice for bragging rights, but the real story is the avg rwhp and torque. You are at your peak numbers for a instant, but the average wins the race.

To really know what you gained, build a spreadsheet with rwhp and torque number columns for each 100 rpm. Add each dyno run done and then subtract each run's columns to see how much you gained or lost.

My last dyno run netted me not increase in rwhp, though torque was significantly higher. But if you compare my previous run, my number went you tremendously in every rpm range. As much as 40 rwhp. Which car is faster? The answer is simple.

Chris
Yeah, my peak hp went up and my average hp went up through the whole rpm band.
 

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Tim,

If the chip helped out with a mid RPM dip that you were experiencing before, then it obviously helped your car's performance and was worth every penny of the purchase. However, with regards to the fact that the chip is what is responsible for your HP/Tq gains across the board, I have to disagree with what has been posted thus far.

When my car was N/A, I dynoed my car multiple times. On one particular day, I saw as much as 4.5 rwHP and 8.0 rwTQ peak gains, as well as respectable gains across the RPM range on back to back runs (both the HP and Tq curves had been shifted upwards in their entirety, similar to what your dyno graph shows). Nothing was changed on the car between the two runs.

For even more proof of the "heating the car's fluids produces more power", take a look at the 2nd page of this post:

http://www.corral.net/forums/showthread.php?s=&threadid=212717

As you can see on this thread, Nino saw up to a 10 rwHP increase after multiple (5) dyno pulls, even after the modification of interest had been removed from his car.

In my opinion, if a modification or tune is to produce a respectable gain across the board, it should do so one pull after a baseline run. For example, on '96-'98 Cobras, you can make a pull while the car is bone stock. If you make a pull, thirty minutes after installing an off-road H/X pipe, you will see gains of 10-15 rwHP/TQ peak, as well as respectable gains across the entire RPM range. There is no need to make 4-6 pulls with the pipe installed until such figures are achieved.

If the third program on your chip really caused you to gain the numbers that you see on your dyno chart, you should be able to reduplicate those numbers by making only one pull on that particular chip setting immediately after one baseline pull on the stock EEC-V.
 

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Discussion Starter #13
Jahel98 The reason that I did'nt see much of a power gain with the first two settings was because I did'nt turn the car off when I adjusted the chip but on the last 2 pulls with the chip set to number 3 it was turned off,I found this out through Chris at JMS.I feel that I have a strong car and I will reduplicate these numbers.:) This is a funny subject if I wore to post that I was making lets say 290 HP then I would here NICE NUMBERS. But when I post what my car really makes in power, Then people just don't believe.:) But thats ok I know what kind of power my car makes, Please don't take this personal.:) :D


Thanks for the kind words Ralph and Onerichrunner!!


TxSnakeCharmer I will have to try the spreadsheet thing.

Tim
 
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