(xposted on NLOC.)

Well, after an extended period of downtime after a blown motor, I am back on the road. After weighing budget, performance and goals, I came up with the following for the long block assembly:

JDM Aluminium 5.4 long block, .020 over, 9:1 CR
JDM Stage II 2V heads, 108lb springs
JDM Stage "2.5" cams (JDM's newest cam timing strategy)
New Ford crank
Coated, balanced and blueprinted with new everything and ARP studs

Supported by:

60# SD injectors
Dual Walbro 255 LPH pumps
Magnum Powers, stock upper, 6# lower
C/L Plenum, SBTB, True Flow filter
Dynatech Headers, Dynatech cats and midpipes, Bassani Catback
AFCO dual pass heat exchanger

PSI Motorsports in Houston put the motor back in for me and got it tuned, to which I was provided with the results:


This particular tune is a "Street" tune, with no more than 12* timing advance. I think the peak boost is only 13-14#, thanks to the heads, headers and midpipes. The stock engine with stock headers and cats would read about 16-18 lbs.

So what do you guys think? I think the TQ is way out of preportion with the HP number, however the curve looks good. The vehicle seems to start pulling HARD around 4K, and starts to drop off around 5.5K. Any suggestions as to what could be done to improve the torque? A couple of Cobra guys seem to think that the Magnum is way too small, and a larger pully would only move the curves, not change the net power, and the motor wants WAAAAY more flow, like what a Whipple could provide.

 

Well you have installed a good tuned long block with all the good stuff from JDM, Why not have Jim look at your data and see what he reccomends.
If you have some data he can look at I might just require a few minor adjustments to your tune.

Just a thought as you have spend a few $$ with them would make sense to have it tuned by them.

 

You can run 600HP with the MP spun up more. Power will be gained across the board. Of course it will never flow as much as a Whipple,but there is a lot left in it now. Pulleys are a lot cheaper than a new blower.
I have my JDM/MP combo about to break into the 10s. I run an 11" lower and a 2.69 upper pulley combo.
Jim

 

Sounds like your running out of blower.

 

That's what I thought. The MP's efficency curve is only being briefly touched with my current config.

 

Not yet. I am still just hitting it's efficiency peak. Usually best times will be run by exceeding this peak to maximize the area under the curve.
I will most likely run out of blower at the 10.7-10.8 ET range. Since I am running heavy this is about the same point that the 2.2 KB is all done as well.
I know the Whipple and new KB 2.6 will move more air, but am awaiting the 3.3 Whipple to be available before upgrading my little MP.
Jim

 

Not completely sure, but I believe that JDM has a great relationship with PSI in Houston. Patrick knows his stuff and is one of the best tuners in the area.

Friday, 11/17/06 Patrick tuned a Lightning that I built a motor for and got 480rwhp and 550tq. That was with a ported Eaton. The outside temps were about 60 degrees.

As a comparison, you should make better power with the Magnum Powers than the Eaton (even ported).

What was the outside temps like when you dyno'd?
Is your tranny in good shape?

 

It was about 86 degrees. The transmission appears to be in good shape. At this point I'm not exactly sure what's up with the torque...

 

In my opinion the first thing to do is break in the motor, say 1000-1500 miles, followed by spinning the living snot out of the MP, I know Jim will not give you the goods on a break in tune, I'm assuming PSI is the same. There is no reason why you can't make another 70-90 HP on the package your running add yet another 50-80 with a KB or Whipple, for my money I'd be ordering some new pulleys and scheduling my next dyno/tuning date. Good luck,T

 

86 degrees is pretty hot for good #'s. I think you might want to go back for a good cold weather tune. All a tuner can do is estimate how the air/fuel ratio is going to react with temp changes. Blowers just add more difficulty to the estimation. I had a tune on my 03 Whippled Cobra done in 99 degree weather and made 480 rwhp and 450 tq, I took it back when it was 60 degrees with the same setup and made 589 rwhp and 572 tq with some tuning revisions. I was running lean with the cooler weather, so revisiting the tune was a good thing.

Are the cams degreed? I have found that makes a huge difference in power with the mod motors!

 

The motor should be good and broken in after the first 30 minutes of running the engine, depending on the ring selection. All you want is good ring seal.

 

Your heads and cams flow better now. With stock heads and cams I make about 600 lb/ft at the 519 rwhp mark. Throw better flowing heads on and the back pressure inside the engine is relieved and the gap between hp and torque numbers drop. The power curve also changes.

 

Glad to hear your back on the road Mop, WOO HOO!!!
CONGRATS on the #'s

For starters, Here you go



As for your TQ numbers Jims newest design Motors are set up that way,
I also asked about that on my old 02 (this is Rob_02Lightning incase you dont know) he builds them like that on purpose, (and for good reason), ask him about it ; o ) . We only need so much tq, too much and it's only trouble putting it to the ground.

Here's my 99 #'s
It's a PSP Built Motor with Patriot Stage 2 Heads, Crower Stage 2 Cams, bla bla bla.... Eaton with A LOT of boost


Dont be disappointed, as said you need to spin the chit out of a Mag to get the Big #'s
AND THEY ARE CAPABLE as Jim just said

Here's my old 02 JDM Motor with Mag and a JDM "KILL TUNE"
Unfortunately I never got to try that tune @)$%@()$%@)$%@)$@$
My street tune was simular to what you have now



Bro your back and have a 500+ RWHP BEAST (WOO HOO), enjoy it get some miles on it, and when your ready BOOST THAT MF UP and fear not there is A LOT more in it : o )

 

Yeah, I've heard from a few others that have this same motor setup (sans the AL block) and exhaust configuration that it flows tons more than what I'm used to and should be using more boost. As a testament to it's efficiency, I found out today that even with the 6# lower, I am only producing 12# of max boost and the tune has variable timing, max *12 @ WOT. So I suppose 500+ HP with a conservative tune and such low boost is a good indicator of scalability. I have a 8# and 10# ring ordered, and I might be hitting up LFP or JDM for a Whipple in the near future.

The sound of this thing is SICK. Not quite the Mustang "hollow" sound, but deeper, like a bear raping a moose before eating it