lets talk dyno graphs - MustangForums.com



4.6L General Discussion This section is for non-tech specific information pertaining to 4.6L (Modular) Mustangs built from 1996 to 2004.

Reply
 
 
 
Thread Tools Search this Thread
Old 01-04-2010, 03:28 AM   #1
0949er
4th Gear Member
Thread Starter
 
0949er's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,909
Default lets talk dyno graphs

Reading another thread and this popped into my head. Take my dyno graph:



What are causes my motor to stop making power at around 5k RPMS, and slowly die off? The idea with the cams is to make power well into the 6k + rpm range correct?

So am I hitting some kind of "limit" with my current setup? Or is that simply the power curve of the engine, and there isn't much you can do about it? I am just curious. Thanks for your help in advanced.
0949er is offline   Reply With Quote
Old 01-04-2010, 09:52 AM   #2
mrtstang
6th Gear Member
 
mrtstang's Avatar
 
Join Date: Jan 2007
Location: MI
Posts: 5,884
Default

The intake manifold is the limiting factor here. Everything looks normal based on your setup.
mrtstang is offline   Reply With Quote
Old 01-04-2010, 09:59 AM   #3
mustangmancp
5th Gear Member
 
mustangmancp's Avatar
 
Join Date: Apr 2006
Location: Missouri
Posts: 4,503
Default

Thank you MRT...i couldn't think of what the answer was. I was sitting here for like 10 mins tryin to figure it out lol.
mustangmancp is offline   Reply With Quote
Old 01-04-2010, 10:04 AM   #4
teej281
4.6L Section Moderator
 
teej281's Avatar
 
Join Date: Nov 2007
Location: South Central PA
Posts: 10,280
Default

Well cams are supposed to make the car pull higher into the rpm band. I mean stock cars stop making power right around 5200rpm's so idk if its the cams he's running or what, but when i usually see a cammed gt's dyno sheet, the power usually is moved up in the powerband some...at least a couple hundred rpm's if im not mistaken. so i dont know why your car only peaks at like 5200-5300.
teej281 is offline   Reply With Quote
Old 01-04-2010, 10:25 AM   #5
mrtstang
6th Gear Member
 
mrtstang's Avatar
 
Join Date: Jan 2007
Location: MI
Posts: 5,884
Default

Those Comp's did shift the powerband a couple hundred rpm higher. No matter what cams you run, the stock intake will be a limiting factor, epecially after 6k.

Given his setup, everything looks totally correct to me. They peak a couple hundred rpm higher, start pulling hard at 4.5k, 30 hp gain at the peak, and have slight losses down low.
mrtstang is offline   Reply With Quote
Old 01-04-2010, 12:37 PM   #6
0949er
4th Gear Member
Thread Starter
 
0949er's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,909
Default

so you think my stock intake manifold is the limiting factor? can you go into more detail? Is it due to lack of air or anything? I'm trying to "visualize" the bottle-neck haha. No real reason, I just want to visualize it in my head.
0949er is offline   Reply With Quote
Old 01-04-2010, 12:41 PM   #7
0949er
4th Gear Member
Thread Starter
 
0949er's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,909
Default

mrstang, are you really pushing 269/305 w/ just a throttle body?

I cant belive that adding a set of cams will only add 15 wrhp and 5 wrtq. What am I missing on your setup? A throttle body / plenum cant possible help that much? (Im just simply
saying that we have pretty much the same setups (minus the throttle body, and I have cams) but we are for the most park makign the same numbers. what gives?
0949er is offline   Reply With Quote
Old 01-04-2010, 01:03 PM   #8
MU71L4710N
5th Gear Member
 
Join Date: Aug 2007
Location:
Posts: 3,189
Default

Quote:
Originally Posted by 0949er View Post
mrstang, are you really pushing 269/305 w/ just a throttle body?

I cant belive that adding a set of cams will only add 15 wrhp and 5 wrtq. What am I missing on your setup? A throttle body / plenum cant possible help that much? (Im just simply
saying that we have pretty much the same setups (minus the throttle body, and I have cams) but we are for the most park makign the same numbers. what gives?
hes got longtubes and other mods?
MU71L4710N is offline   Reply With Quote
Old 01-04-2010, 01:14 PM   #9
0949er
4th Gear Member
Thread Starter
 
0949er's Avatar
 
Join Date: Mar 2009
Location: NC
Posts: 1,909
Default

Quote:
Originally Posted by MU71L4710N View Post
hes got longtubes and other mods?
I know, thats what im saying.


We have the same mods EXCEPT I have cams and he has a Throttle body. Yet, we are making almost the same numbers.

Im just saying that in comparison, my numbers look low.
0949er is offline   Reply With Quote
Old 01-04-2010, 01:21 PM   #10
WannaBeGearHead
Go Texas!!!
 
Join Date: Jul 2009
Location: Lincoln, NE
Posts: 4,607
Default

With adding cams you added more power. To make more power you need more fuel and air. So when you are at a higher rpm your car is demanding more fuel and air. On the fuel side of it you are ok but you aren't getting enough air into your engine to make hp at a higher rpm.

We had a recent thread talking about the Edelbrock Victor Jr intake manifold. A guy over at Corral had ported heads, cams and bolt ons. With the Edelbrock he made over 50rwhp more at 6000rpm than he did with the stock manifold. Which allowed him to keep making power longer.

Think of it like you are running your fastest but you are breathing through a straw. You wouldn't be able to run your fastest for to long and would eventually start to slow down. Now take the straw out and run your fastest. You will be able to go your fastest for longer. That isn't the greatest example but you should get the point of what your intake manifold is doing to your car.

Also when you add your s/c, your intake manifold is going to continue to restrict air at higher rpms. Sxynerd had one in his setup and loved it.

Last edited by WannaBeGearHead; 01-04-2010 at 01:23 PM.
WannaBeGearHead is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
window tint issues? chrisdbassplayer 2010-current S197 Appearance Section 4 10-13-2015 07:53 PM
04 Mach 460 system, Installed Aftermarket HU, No Highs/Tweeters breaking Audio/Visual Electronics 5 10-02-2015 02:27 PM
Hello All RCS02v6 New Member Area 4 09-29-2015 02:46 PM
Mustang Most Popular First Car on Instagram MustangForums Editor Mustang News, Concepts, Rumors & Discussion 1 09-10-2015 12:46 PM


Tags
270ah, 46, 50, camshaft, dyno, edelbrock, graph, graphs, heads, mach, max, mustang, power, s197, stock

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -5. The time now is 10:01 PM.