Cobra lost power after installing Crane 2031 cam

[SVTtripleblack]

So, I just got off the phone with the guy who installed my crane 2031 cam. He said after putting it on the dyno the car lost power from my previous numbers with the stock cam. After he played around with the timing he said he got the peak numbers back to where they were before the cam install, but I lost a decent amount of midrange hp and torque. Before the cam my car was making 255rwhp and 299 torque with the bolt-ons in my sig. I know I only have the stock gt40 unported iron heads and intake, but this is a fairly mild cam and I've seen other peeps with the same setup make at least 10-15rwhp off installing this cam. Any ideas why this happened. I'm going to pick the car up on Fri., so I haven't gotten a chance to drive it yet. Should I ask him to pull the chip and re-dyno the car to see if the chip was interfering with any values? Maybe he didn't pull the spout when setting timing? I don't know, but I'm really bumed out. I thought I would be making closer to 270 at the wheels and have a decent cam for a vortech blower in the future. What should I do?

 

[SVTtripleblack]

I'm thinking about asking him to pull the chip out and re-dyno the car. The chip has a mail order tune on it and I think it's not working well with the cam. Does anyone know if this is a possibility? Anyone have a fairly stock cobra with this cam and what kind of #'s are you making? Thanks

 

[final5-0]

The obvious stuff like ... was it all installed correctly would be first on the list of things to suspect.

If all that is good to go ... next things I'd wanna know would be how is the spark setup as far as how quick it comes in and total amount of advance.

And of course ... and how does the fuel ratio look

As has been said here before ... pics of the pull would certainly help

Heck Fire ... for all you know ............
he may have done the pull on a Mustang Dyno

Grady

 

[SVTtripleblack]

The obvious stuff like ... was it all installed correctly would be first on the list of things to suspect.

Well I don't know for sure, but they do engine work all the time.

If all that is good to go ... next things I'd wanna know would be how is the spark setup as far as how quick it comes in and total amount of advance.

He said 30 some degree of total advance. I can't remember the exact number.

And of course ... and how does the fuel ratio look

He said he got it to where it was before after adding some fuel, around 13 to 1.

As has been said here before ... pics of the pull would certainly help

I will only have that on Fri. unfortunately.

Heck Fire ... for all you know ............
he may have done the pull on a Mustang Dyno

Ha I wish, it's definately a dynojet.

Grady

Thanks Grady, I always respect your advice and I know you are an eec tweecer guru Do you think the chip could be suspect? I don't know enough about how many parameters could be changed with it to do any damage after the install. Do you think maybe he didn't disconnect the spout to advance timing. Maybe if he's used to older stangs? I would call him now, but I don't want to be rude by calling him at home at night. I will try to give a ring in the morning I guess.

 

[final5-0]

Honestly

You are either gonna work with an afpr and twist the dizzy
MECHANICAL ADJUSTMENTS

or

You are gonna manipulate the pcm parameters with a chip or an interface
CUSTOM TUNING

I just kinda see it as ... It all boils down to that

To try and mix the two reminds me of a couple of old sayings

Don't burn down the barn to get rid of the rats
and
Don't throw out the baby with the bath water

I think you need more info about how he ... "tuned" ... your Stang

Grady

 

[SVTtripleblack]

Honestly

You are either gonna work with an afpr and twist the dizzy
MECHANICAL ADJUSTMENTS

or

You are gonna manipulate the pcm parameters with a chip or an interface
CUSTOM TUNING

I just kinda see it as ... It all boils down to that

To try and mix the two reminds me of a couple of old sayings

Don't burn down the barn to get rid of the rats
and
Don't throw out the baby with the bath water

I think you need more info about how he ... "tuned" ... your Stang

You know,.. the thing that gets me about this place is that they have a dyno and they are an authorized Diablosport dealer, but they are tuning my car manually. And doing it manually even though I have a diablosport chip. That's why I went there in the first place. I figured I could get them to do the cam and then dyno it right there to save me a lot of hassle. I guess I was wrong.
Maybe I'll just tell this guy if he's too scared to use his own equipment I'll take my business elsewhere. Ha, he'll probably just be happy to have me out of his hair at this point.

 

[SVTtripleblack]

He adjusted the fuel pressure with an afpr, which I don't get because I don't even have one on the car. I tried to tell him that I thought my computer would re-adjust the fuel on its own and that it would cancel out anything he did. He said it shouldn't when I'm at wide open throttle. Is this true?

 

[final5-0]

You know,.. the thing that gets me about this place is that they have a dyno and they are an authorized Diablosport dealer, but they are tuning my car manually. And doing it manually even though I have a diablosport chip. That's why I went there in the first place. I figured I could get them to do the cam and then dyno it right there to save me a lot of hassle. I guess I was wrong.
Maybe I'll just tell this guy if he's too scared to use his own equipment I'll take my business elsewhere. Ha, he'll probably just be happy to have me out of his hair at this point.

Over the years, I've seen so many posts put up on here and other sites that are very familiar to this one.

It seems like if one doesn't talk to the guy doing the tuning and get very specific with what is expected, the out come leaves much to be desired

I'm not picking on this guy
but ... just throwing out an observation that seems to be kinda common when peeps go to get their Stang tuned.

You would think since you already got a chip ... they would do a reburn

Grady

 

[final5-0]

He adjusted the fuel pressure with an afpr, which I don't get because I don't even have one on the car.

That does sound kinda strange

I tried to tell him that I thought my computer would re-adjust the fuel on its own and that it would cancel out anything he did. He said it shouldn't when I'm at wide open throttle. Is this true?

I gotta tell you the honest truth

I've never owned an afpr so I really don't have any REAL experinece with one to be able to give you hard data with my personal findings by using one.

I can tell you I've chatted with other self tuners who have told me you can see things change when you hose around with the pressure.

I've also seen Don 95Vert say over time, you will see the mix change when you move the pressure around.

As far as I'm concerned ... if Don says it is so ..........
I'm gonna have to believe it as he is the Man when it comes to tuning

I've learned so much from him over the years

Grady

 

[SVTtripleblack]

Over the years, I've seen so many posts put up on here and other sites that are very familiar to this one.

It seems like if one doesn't talk to the guy doing the tuning and get very specific with what is expected, the out come leaves much to be desired

I'm not picking on this guy
but ... just throwing out an observation that seems to be kinda common when peeps go to get their Stang tuned.

You would think since you already got a chip ... they would do a reburn

Grady

Well tomorrow I will ask him to dyno the car without the chip. If my hp and tq numbers increase, then I can confirm something is up with the tune on the chip. If it does increase, I will ask him to do a reburn on the chip. Being that I've never seen any values on my computer via a tweecer or laptop program, I don't really know what values should be changed. I also feel (unfortunately) that this tuner doesn't know how to properly remove things like the timing retard btw. shifts.
I asked him to do it before and he said that he contacted someone from Diablosport and that this person said the tip-in-retard only occurs on automatics, which I know is B.S.

I just think I should have picked up some power. I know my heads don't flow the best, but from other combos that I've seen, it seems like they flow good enough for a mild cam like the 2031.

These are the only things I really want done to my tune besides optimum hp and tq.

1. I would like to have the timing increased
2. I would like to have the fan speed come on lower than stock (I don't know what temp would be best)
3. I would like the tip-in-spark retard eliminated btw. shifts.
4. An air-fuel ratio of around 13 to one.

Do you know how to remove the tip-in-retard btw. shifts on these cars, so I can tell him what to do? I could go somewhere else, and I will if this doesn't work, but I want him to do this right without being charged more cash.
Thanks

 

[WhiteCobra95]

The practices sound a little bit strange for a tuner shop. A good tuner should adjust fuel and spark through the ECU calibraiotn, not by shifting the distributors base timing and messing with fuel pressure to set AFR.

 

[SVTtripleblack]

The practices sound a little bit strange for a tuner shop. A good tuner should adjust fuel and spark through the ECU calibraiotn, not by shifting the distributors base timing and messing with fuel pressure to set AFR.

I know and I'm really p-eed off big time. I chose this place because I did a search on Diablosports' website for the closest tuners to my area to do a tune for me. They were the closest, and by talking to them on the phone about doing the cam and tune they acted like it was no big deal. I thought since they deal with Diablosport software that they would be good at using it. I feel ripped off big time, and I will let them know about it tomorrow.

I think they were trying to mess around with it manually so they didn't have a reason to charge me extra. Probably because they felt bad about not getting anymore power out of the car.

I mean I'm I crazy here, I should see an increase of power with this cam shouldn't I? I thought it was designed around gt40 heads?

 

[WhiteCobra95]

Here's part of a replay I submitted to another forum:

One way to alter fueling is to modify the fuel pressure like you mentioned. This is normally done with an adjustable fuel pressure regulator. Deviating from the factory rail pressure shifts the flow rate of your injectors globally. [To calculate the shift, take the square root of the quantity new pressure divided by the factory set pressure, and then multiply this correction factor with the original injector flow rate @ factory set pressure. For example: SQRT(50psi/45psi) * 19lb/hr@45psi = 20.02 lb/hr @ 50psi] This is one way to increase or decrease your fueling without having the ECU tuned or buying a tuner. However, there are a couple down sides. Like The ECU will read a richer exhaust mixture (assuming that you increased the pressure/flow rate) through the O2 sensors in the exhaust flow and start learning out the shift by shortening the pulse width sent to the injectors. (This is a good thing since you want to run at an AFR of 14.7:1 under light load/cruising conditions.) The bad part is that this adaptation range is limited. If you push it to the limits, you could set a check engine light or suffer from poor drivability. At engine loads like WOT this adaptation does not run, so you would end up with more or less fueling based on the magnitude of your pressure shift. The biggest issue is that it’s a rough adjustment at best. … Long story short, the best way to change your AFR is through the ECU’s fueling tables and check it with a wideband sensor mounted upstream of the cat.

I hope this helps. - whitecobra95

 

[final5-0]

Sure I know how to kill the tip in retard but that is with a Tweecer and the older software at that ... so ... ANY input I might offer is not gonna help you as he does his thing with a different tuning method.

The bottom line with this guy or any other Pro Tuner is they know their supporting equipment and are compentent with the particular method they use to tune a Stang.

Heck ... You can say the same for those of us who do their own tuning

I mean ... Take me for example

I'm just some Hick from Texas who found a laptop

I hope things turn out good for you with the new combo

Grady

 

[SVTtripleblack]

I hope things turn out good for you with the new combo

Thanks man, I have very little faith left. I'm just going to pray that I dyno better without the chip and get this guy to reset my fuel pressure and reburn my chip.

 

[WhiteCobra95]

This is almost like a chat room tonight! ... and seeing Grady posting real time is like talking to a forum celeberty!

I am a professional calibrator, and have been for about 10 years. Every peice of advise Grady's given is corect.

This is going to be a hard one to figure out. I would take a look at your water pump and timing to cover for signs of new gaskets/sealer as evidence that the swap was actually done. The crane cam you called out has a pretty lumpy idle from what I remember from other people's comments. Also, get your original cam back!!!! and check the part number if possible.

Was your baseline dyno run done on their dyno? If you did it somewhere else, it might not correlate to their dyno directly since the load cells can deviate from one facility to another and like Grady mentioned, a mustang vs. a superflow dyno can have very different results.

 

[WhiteCobra95]

I would also ask the tuner how he adjusted the spark. If he only twisted the distributor, then he's really not earning his money. The correct way is to increase the spark in the tables, make a dyno pull, listen for light kncok (and look for more rear wheel torque). If it doesn't knock, you can usually bump it up anotehr degree or two and then back it off a couple when you finally do find the knock limit. The new cam with more overlap will have different breathing behavior from your previous cam, and can probably tolerate more (or sometimes less!!!) spark advance because the internal EGR rates can change.

 

[SVTtripleblack]

Was your baseline dyno run done on their dyno?

Yes, my baseline was done on their dynojet. I'm going to demand that he redoes it tomorrow w/out chip.

 

[rj95svt]

Unfortunatly not all tuners are familiar with the 94 and 95 cars. Alot of them just think they can throw a cam in adjust the fuel pressure and base timing and be ok similar to a fox body. It's not ideal with a fox but it can be gotten away with alot of times. There are some tuner that don't have the equipment to burn a chip either I have seen one that is only setup for the flash tuners on the 96 and later cars.


What was the A/F ratio when he dyno'ed the car before and after the cam?

 

[SVTtripleblack]

What was the A/F ratio when he dyno'ed the car before and after the cam?

All I know for now is that is was at 13 to 1 before installing the cam, then it was running lean after installing the cam. As far as by how much,.. I don't know. I will pick the car up on fri. if he can't be any help and look for a tuner that works with stangs.