Solutions to a compression problem. - Ford Mustang Forums : Corral.net Mustang Forum
 
LinkBack Thread Tools Display Modes
post #1 of 7 Old 01-04-2008, 09:20 AM Thread Starter
Registered User
 
strokercharged95GT's Avatar
 
Trader Feedback: (2)
Join Date: Jul 2003
Location: Tampa
Posts: 1,196
Solutions to a compression problem.

I have a 10.5:1 compression motor that has run fine with a SC for years with a linear boost curve up to 8.5 psi. I have only blown headgaskets twice in this time. Now I have a turbo that gives me full boost by 2900. Now im only running 6 psi now and for 90 of the power curve I have no problems with pinging, but on the upshifts where i go into third or fourth gear that initial hit of boost and lugging on the motor i can hear pinging. This is a combo of the high compression and the lugging effect. The way I see it is that I have 2 solutions other than motor work. I could put an electronic boost controller on the car and turn the gain down so the boost hits more gradually allowing the RPMs to climb, sorta letting the motor rev up some before taking full boost. Or I could just add a meth/water injection kit. Any ideas on the best direction? or any flaws in my thinking? BTW no matter how much timing i pull or fuel I add it makes no difference.


1995 Mustang GT - 347 - PT7576
2004 Mazda RX8 - 13B-REW BWS362
2013 Mercedes GLK-350
strokercharged95GT is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 01-04-2008, 09:29 AM
Registered User
 
Trader Feedback: (0)
Join Date: May 2006
Location: Houston, Tx.
Posts: 4,744
One problem is your stock EEC computer
Even with Tweecer it's till a stock computer that
is prone to timing errors at higher rpms.

Wandering timing is not good. It wasnt your compression and boost
that blew out those head gaskets, it was detonation from the computer
letting the timing drift around a couple of degrees.

1. Water/Meth would help
2. Head swap to 64cc chambers to lower compression would help
3. Better computer like the AEM would help tons too.

Do you have an intercooler in the system? If not that would make
a huge difference too.


Democracy is two wolves and a sheep sitting down and voting on whats for lunch.
r.barn is offline  
post #3 of 7 Old 01-04-2008, 09:37 AM Thread Starter
Registered User
 
strokercharged95GT's Avatar
 
Trader Feedback: (2)
Join Date: Jul 2003
Location: Tampa
Posts: 1,196
yes I have a nice front mount that is nearly frozen when driving around this time of year, so heatsoak isnt an issue. timing at high RPMs isnt that bad part is seems to be tween 3000-3500 when the motor lugs and the boost hits from changing gears and stepping on it. My A/F is around 11.0 in OL at high loads and it is confirmed with my wideband. My timing is 10deg base with 9 degrees being pulled out at 6 psi. I know low compression pistons would be the best route but i cant see taking apart a well running motor to swap pistons, especially since mine are already forged JE's. Either way i think meth injection would fix the problem, but if I could get the EBC to correct the problem instead I would go that route.

1995 Mustang GT - 347 - PT7576
2004 Mazda RX8 - 13B-REW BWS362
2013 Mercedes GLK-350

Last edited by strokercharged95GT; 01-04-2008 at 09:46 AM.
strokercharged95GT is offline  
Sponsored Links
Advertisement
 
post #4 of 7 Old 01-04-2008, 10:03 AM
Registered User
 
Trader Feedback: (0)
Join Date: May 2006
Location: Houston, Tx.
Posts: 4,744
It's not just engine rpms

The stock computer really just is not accurate enough
to keep up with an engine that needs PRECISE timing control like
yours does.

Water/Meth should take care of your probs.
If you dont mind worrying about running out of juice or having
to keep tank filled, that's what I'd do.

Myself, I did a head swap to lower compression
After I sold the used heads it only cost me about $400 and
got some better heads on there at same time.

Democracy is two wolves and a sheep sitting down and voting on whats for lunch.
r.barn is offline  
post #5 of 7 Old 01-04-2008, 12:30 PM
Registered User
 
Trader Feedback: (5)
Join Date: Jul 2006
Location: Oahu, Hi
Posts: 284
The stock computer is NOT what allows timing to wander. It is the stock ignition system itself. The only cure to that is a crank trigger. You could easily lower your compression a point or more with a thicker gasket. Not the optimal way of doing it, but quench is not at all important in a turbo motor. Oh, water/meth injection will eventually rot the inside of your engine. KISS (keep it simple)Hope this helps.
nealysa is offline  
post #6 of 7 Old 01-04-2008, 03:59 PM
Registered User
 
my8950's Avatar
 
Trader Feedback: (7)
Join Date: Dec 2000
Location: about 2000 posts short...
Posts: 1,782
Lowering the compression would help the best, doing it right would be ideal. Head gaskets are not the way to lower compression, they will but not effectively/properly without causing other issues. Adding a boost controller would be a band-aid, but its kinda like taking away what you've put the turbo on the car for which is to make power....What happens if you set the timing at 8* and pull the spout and run it locked? Does it still ping?

I dont think water or meth injection will rot the engine either, we're running on alcohol now at the local gas stations...Its harsh, but the components are made to use it now too....

"All your base are belong to us"
my8950 is offline  
post #7 of 7 Old 01-04-2008, 07:08 PM
Registered User
 
Trader Feedback: (5)
Join Date: Jul 2006
Location: Oahu, Hi
Posts: 284
You are correct. I did mention a gasket is not the optimal way to lower compression. A boost controller is not a band aid either. It controls boost to allow you to have traction with the maximum speed and boost. None of the internals are made to not corrode when exposed to temp. cycles and water and methanol. Eventually they will need to be cleaned, replaced, or have corrosion control done. You are correct to suggest timing adjustments, though. Good call. Don't go too low or you will lose power and your headers will heat until they are bright orange.
nealysa is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forums : Corral.net Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome