Hib Halverson

Hey Tony-The intake manifold volume of the MSD is substantially greather than the stock intake. HPTuners does not support access the manifold volume parameter, whereas EFILive does support it so, with EFILive, you can adjust the cal file to reference the correct volume.

In light of that, do you still feel either editing application will do when doing the cal for an LS7 with an MSD on it?

Bad_AX

What is the significance of intake volume on power potential, idle quality, tuning etc?

RX-Ben

Does anyone know what aftermarket fuel rails will work with the MSD intake?
It seems to be designed around the OEM rails.

EGOCHKR

Any aftermarket will work but this is I think the only intake to work with stock rails to save you money... I am making 623 rwhp with stock rails...

RX-Ben

I need someone to tell me the rails that have been verified to fit. The manifold has bulges near/in-line with the injectors which would seem to require something like the nipples on the OEM rail.

Tony @ Mamo Motorsports

IMO it wont make a difference in the final results......the air the manifold will allow to pass thru it is all the same (the air doesn't know or care what tuning software is being used obviously).....the end results from that air at various RPM points and its ratio of fuel is easily adjusted through either tuning software. Given the same A/F ratio when the smoke clears and the fact we established its moving the same amount of air, should produce equal power assuming the timing and everything else is held constant.

The larger plenum certainly does effect how well it moves air at various points in the RPM curve but we are already looking at the net results of that with our wideband and adjusting accordingly

-Tony

Sébast19X

Hi Hib, you have to send you'Re file to Hp tuner and they will add this parameters for you. It's mostly used for tip in /transient fueling.

Seb

MyLS1Hauls

As mentioned above, it is the transient/tip in fueling that needs to be addressed, when changing intake manifold volumes. Under WOT acceleration, it doesn't matter.

When you crack the throttle open from idle, air quickly rushes in, to fill the manifold plenum that is under high vacuum. The MAF reports this as high air flow, but that air isn't immediately consumed by the engine...it first has to fill the intake that is under vacuum. There is a split second delay, as that volume is filled, before it starts actually filling the cylinders. This can cause a stumble or hesitation, if this delay isn't properly accounted for, with regards to fueling. The same phenomenon happens with the stock intake manifold, but its volume has been properly accounted for.

The reverse also happens. When you slam the throttle shut from WOT, there is a split second that the engine is still consuming air from within the intake manifold, until a vacuum is produced.

This delay is the reason why smaller volume intake manifolds have sharper throttle response.

Michael_D

^^^^
Which is one compelling reason to properly calibrate VE. And with the gen IV GM ECMs, VE Coificients, which also include transient Coificients. There currently is no good method for calibrating the transient Coificients, so I believe the table Hib is referring to, that EFI LIVE has will help.

I wonder though. ..... Would the larger plenum volume help reduce pressure wave interactions from increased reversion (IE: finite-amplitude waves/Hemholtz resonation)? I think it might.

Sébast19X

Michael, just sent you're .hpt file to hp tuner and ask to them to add this parameter. Both version work, 2.24 and 2.25.

Seb

JMB

Where is this located (which tab)? I have version 2.241170

Dan_the_C5_Man

Seb's English is better than my French, but from his posts I believe he is asking folks to request HPT to add this parameter. Could be wrong - I will do an upgrade tonight, check it out.

Sébast19X

Hi sir, you have to send the file of you're car to hp tuner support email and you have to ask to them to add the intake manifold volume parameter.

They will return you the new file within 24hrs with the parameter added .

This is the way I have done it for my own car, and some of those that I have tuned.

Hope this help,

Best regards,

Seb

JMB

Perfect, thanks Seb!

Hib Halverson

Last year, I asked HP Tuners repeatedly to add "intake manifold" volume but I never received a reply to that request nor has it been added in succeeding versions of 2.24 or 2.25.

After waiting a while for HP Tuners to act, I decided to use EFI Live to do the cal. on my LS7.

I have had the correct manifold volume in the cal from the get-go and, thus, have not experienced any anomalies in throttle response.

Admittedly, the EFI Live interface isn't as friendly but in this case–where the aftermarket manifold's volume is so much larger than stock–EFI Live wins.

In HP Tuners' defense, I've noted that HPT supports a greater amount of platforms. For example, I was able to tune 4th Gen F-cars with 3800 V6es using HP Tuners whereas, EFI Live does not support that engine.

Generally, they are both good programs but in specific applications, sometimes EFI Live wins and in others HP Tuners wins.

Hib Halverson

I don't know about that specifically, but I do know the manifold was developed using a lot of CFD studies which can model airflow the way it really is in the engine, ie: with pulsations and waves typicaly of a plenum being sucked on by intake ports with valves opening and closing.

But even if there is a problem such as "Michael D" suggests, the fact that stock engines stand to gain 20 or so horses and modified engines as much as 40 would tend to make any problem with pressure wave interaction a minor concern at best.

Da Z06

Agreed.

Michael_D

No. You misses a key word I used - "reversion". Now think theoretically and wait for the bulb to illuminate, and you'll see that your analogy has no relation to my comments.

And I did not say there was a problem, with respect to this intake. Reversion, however, is a problem.

Michael_D

Cool! Thanks bud!

But now that they figured it out, I wonder why it isn't in the current 2.24.xxxxx version?

Hey did you ever get that newer E38 retrofit in your car figured out?

Unreal

Newer e38 is a simple swap if you know what you are doing.

I'm tempted to try one of these on my blower car. For $1000 that is a LOT less than $2800 on a PMC intake.