Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Roadmister on April 16, 2023, 11:13:37 PM

Title: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Roadmister on April 16, 2023, 11:13:37 PM
Going on a few months now that enjoying my new to me 85 Turbo Coupe, 5-Speed stick, T-Bird. This one is a driver that purrs like a kitten and hums along at higher RPM s.  Open for consensus from group, Both opinion and fact ?
What is considered abuse, or what these 2.3 Four cylinder motors were designed for?
This is not as my daily driver and I like taking it out on a weekend morning when traffic is quiet and running the tach around the 4000 RPM range for extended intervals through the local twisted back roads.
(which feels to me on this motor, as what I'm calling the "sweet- spot" around 4K )
Over the years I've restored my share of muscle V-8s. This 4-cylinder stuff is new to me, so far I'm impressed.
Title: Re: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Mikey97D on April 17, 2023, 08:22:20 AM
Both nice cars!  Beautiful Bird.

I am not sure about the "happy spot" in RPM for that year since there were several changes after '87 that could change that.  Chuck and others will probably be the best go to for that information.

Is the car still stock or any changes been made to it?

Title: Re: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Roadmister on April 19, 2023, 03:14:57 PM
I have to credit the previous owner on thorough job of rebuilding the 2.3 and adding an aftermarket inter-cooler. I don't know if it has any internal upgrades. The vehicle runs great but I'm sure it's not at it's full potential of more low end torque. Unfortunately it passed through another owner whom I suspect experimented with the vacuum & boost lines.  Again I'm educating myself on this and enjoy the challenge of sorting it out.
Title: Re: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Mikey97D on April 20, 2023, 01:44:19 PM
Very nice that is has the FMIC on it.

Are the rear brakes disc or drum?  '85 originally came with a 7.5" rear end with drums.  In '87 they went to a 8.8 rear with either 3.55 gears (manual transmission) or 3.75 gears (automatic).  Originally the '85 came with a T3 Turbo (not sure whether .48 AR or .63 AR). 

A larger than stock exhaust will allow the turbo to spool quicker.  I believe stock exhaust was around 2.25".
Title: Re: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Chuck W on April 20, 2023, 08:42:47 PM
2.3T's sounds like an angry tractor, no matter what you do to them.  :toothless:

The "sweet" spot all depends on mods, etc.

For corner carving, 4K is probably fine. Not going to hurt anything. For highway cruising, I like to keep the rpms down under 3K (70 mph)
Title: Re: 2.3 Turbo Crusing RPM Sweet Spot?
Post by: Roadmister on April 21, 2023, 06:39:54 PM
Appreciate the input on engine speed.
This has drum rears. Exhaust is on the to do list, I'll explore the 3".