Cobra intake installed and running!

Tiltedhalo said:
Again there is nothing I repeat nothing with the intake manifold volume that will effect idle, period. If the idle is fluctuating its a vacuum leak, IAC, timing ect. not manifold volume. I run a cobra intake with a 1/4 inch hat spacer 1" throttle body spacer and split cut back runners and have mine set lower then the stock gen2 intake, and even with the stage two cams I can get the idle rock solid at 700RPM.
PS and have no problem with timing or fuel curves.
Click to expand...

+1

7 swaps and counting, no issues whatsever without touching the volume parameter.

Put the stock tune back in the car, it will idle fine. It's probably the sniper gizmo ;) or the IMRC deletes adding to the problem.
 
+2 for Tiltedhalo, swapped the gen 2 IAC on there and it idles perfectly, also got rid of the ultra snappy throttle response right when you press the throttle. The Sniper tune works just fine, I may end up with adding more low end timing, not because throttle response is lacking, just to get it to idle at around 10-15 degrees of timing like before... BTW, the car is definately louder at idle and when accelerating versus the gen 2 intake manifold. Interesting datalogging fact, the car was seeing 200 KG/H of airflow at idle before and now it sees 330 KG/H of airflow...
 
hey 98lsc32v, did you use the EGR delete in the sniper tune? if you did it will remove some timing at specific EGR cycling times to help prevent detonation. If you data logged before check your timing and adjust to about 1.5 to 2.0 deg. less at those points.
 
Yes I deleted the EGR with the Sniper. If it will remove some timing to take that into account, why should I remove more timing? I don't understand? I haven't been able to datalog anything but idle so far...
 
Sorry I meant add timing up to 1.5 to 2 deg less then with the EGR, best with a little trial and error.
 
My car was pinging bad. Changed JUST the intake volume and it was like a new car.

Either way I guess I would rather have the correct parameters that match the hardware of the car than alter anything else to compensate.
 
This is from a Ford engineer, the manifold volume first is not even in Liters and most programers think its liters and use that conversion it is not and is not the hexadecimal equivalent. Take a look at the base programs on a wide sample of Gen2 Mark VIII's and you will find a large variance in this setting depending on the vehicles origins.
This is one of the parameters for altitude if your car was purchased in Fl and you moved to CO you should have the calibration changed. This setting will effect base fuel parameters for altitude correction.
 
unity said:
My car was pinging bad. Changed JUST the intake volume and it was like a new car.

Either way I guess I would rather have the correct parameters that match the hardware of the car than alter anything else to compensate.
Click to expand...

How could you tell your car was pinging, did you datalog it? You shouldn't be able to hear audible pinging since the 4.6 DOHC has knock sensors... in any case, your swap is quite a bit different, you changed long blocks, I just swapped an intake, fuel rail and deleted the imrc's and egr...
 
98LSC32V said:
How could you tell your car was pinging, did you datalog it? You shouldn't be able to hear audible pinging since the 4.6 DOHC has knock sensors... in any case, your swap is quite a bit different, you changed long blocks, I just swapped an intake, fuel rail and deleted the imrc's and egr...
Click to expand...

There was audible pinging and a timing was adjusted something bad but not enough. Changed just that one parameter and bingo.

No matter what. The right base parameters should be entered for the right hardware. Not doing so is just being lazy or stupid.
 
Tiltedhalo said:
This is from a Ford engineer, the manifold volume first is not even in Liters and most programers think its liters and use that conversion it is not and is not the hexadecimal equivalent. Take a look at the base programs on a wide sample of Gen2 Mark VIII's and you will find a large variance in this setting depending on the vehicles origins.
Click to expand...

Which Ford engineer. And that engineer should know the Mark VIIIs only had only one origin.
 
Gee whiz then every 97 should have the same exact PCM and box codes........ and 98 so on and so on.
 
so how did the IMRC delete work out do u feel a loss of power on the low end also has your mpg been affected?
 
The car feels better all throughout the rpm range, no low end loss at all... but I do have 4.30 gears, not sure how it would feel with 3.27's. As for MPG, I don't keep track of that...
 
Tiltedhalo said:
This is from a Ford engineer, the manifold volume first is not even in Liters and most programers think its liters and use that conversion it is not and is not the hexadecimal equivalent. Take a look at the base programs on a wide sample of Gen2 Mark VIII's and you will find a large variance in this setting depending on the vehicles origins.
This is one of the parameters for altitude if your car was purchased in Fl and you moved to CO you should have the calibration changed. This setting will effect base fuel parameters for altitude correction.
Click to expand...


all the second gens have the same manifold volume
and it's marked as and I quote
manfold_volume_[Liters]

I looked at 5-6 different second gen codes and they all are 6.87500000
all the same down to the .00000000
*shrugs*

The only difference I see is between First AND second gens, all the second gens are the same size.
 
98LSC32V said:
The car feels better all throughout the rpm range, no low end loss at all... but I do have 4.30 gears, not sure how it would feel with 3.27's. As for MPG, I don't keep track of that...
Click to expand...

thanks that good to know, and yea mpg is not that big a deal lol.
 
Tiltedhalo said:
Gee whiz then every 97 should have the same exact PCM and box codes........ and 98 so on and so on.
Click to expand...

no they have different box codes, but all 97's use the same strategy and all 98's use the same strategy.
ALL the box codes have the same value for manifold volume.

I could list ALL the box codes and the values for ALL the manifold volumes, but it would be very very redundant.

You dont know "why" there are different box codes, do you?
it's not because they use "different tunes" or calibrations.

99% of the reason for different box codes is because if after the car was released, "if" there was an issue.. they wouldn't have to "recall the entire model line", only cars with particular box codes.

(^ THAT was straight from THE ford engineer, not from "A" ford engineer)
 
So whats the deal with the manifold volume, is it really important or what.
You think I'll get any gains by tuning for the right volume. Is this an issue that would be more problematic at higher elevations.
 
htrdlincoln98 said:
So whats the deal with the manifold volume, is it really important or what.
You think I'll get any gains by tuning for the right volume. Is this an issue that would be more problematic at higher elevations.
Click to expand...


There aren't really any "gains" by having the correct manifold volume.
but there are far more important things in PCM tuning than "gains".
Economy, Driveablility and Fuel control ALL depend on a correct manifold volume.

A car with an incorrect manifold volume could possibly be slower than one with the correct figures, but I am not saying this manifold volume is a "huge power maker".

BUT.. if you want to have a properly running/tuned car then you really need to address the manifold volume.


this is the same as changing the manifold on a carbed car, it IS going to change the tune, and will require making changes to the tune.

I see some supposed "experienced" people saying Manifold is a non issue, I guess I "gave them more credit" than I should have.

manifold volume is very very important.
 
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