Jump to content

Question pertaining to govener


Old Man Jimbo

Recommended Posts

Well in a bit I would offer to do it for a few dollars, but that is a couple months down the road, after I play with my tune for a while. 

In the mean time I would suggest Ryan at sinister performance.  (Gmtuners.com). He has been doing it for a long while. 

You can also have him adjust the fan turn on points.

  • Like 1
Link to comment
Share on other sites

3 hours ago, Ronnie said:

Seems like I remember someone saying the governor is set at 115 mph. Wouldn't a 3400 lb car with 165 hp hit the governor about the same time it ran out of enough horsepower to go faster?

Probably getting close. I suspect the fuel cutoff may vary some by year, but I don't remember if there is both a mph and rpm cutoff. In many cases there is a speed limiter based on the standard tire speed ratings, which in a Reatta would be "H" or 130 mph, probably with some safety factor, 115-125mp sounds about right.

As an unscientific experiment in the realm of useless information, I modulated the throttle where the indicated manifold vacuum was 5"Hg. The car accelerates moderately well at first and slowly dies off. After a run of almost 3 miles on a straight road I was just approaching 100mph but never reached it. Rpm was about 2800.

  • Like 1
Link to comment
Share on other sites

27 minutes ago, 2seater said:

As an unscientific experiment in the realm of useless information, I modulated the throttle where the indicated manifold vacuum was 5"Hg. The car accelerates moderately well at first and slowly dies off. After a run of almost 3 miles on a straight road I was just approaching 100mph but never reached it. Rpm was about 2800.

 

A little over my head. What does that mean in terms that I can understand? :)

Link to comment
Share on other sites

Factory top speed limiter (programmed into the ECM calibrator chip) for all Reattae is 125 MPH. ECM cuts the 1fuel injection at 125 to force a reduction in speed. Kind of a moot point as the stock 3800 runs outta juice right about that point anyway. And the tire speed rating is something to keep in mind, just asking for a tire to shred at those speeds unless running V or Z rated tires.

  • Like 1
Link to comment
Share on other sites

6 hours ago, Ronnie said:

 

A little over my head. What does that mean in terms that I can understand? :)

It is sorta useless info except to say that while still registering vacuum that mean the throttle was not close to wide open, where it will register as zero. Because I have a vacuum/boost gauge, I just notice little things like that. Generally see 10"-12" vacuum on the gauge at normal highway cruise in the 70ish mph range. By and Iarge I see no real difference if I have a turbocharger on it or not. It just gives a sense of how hard it is working to flow down the road. I think reading the MAF gives a sense of how hard it is working as well.

Link to comment
Share on other sites

3 hours ago, Ronnie said:

Thanks. Now I get it. You were just selecting the 5"Hg as a reference point to observe the load on the engine I assume.

Exactly right. Remember the old Mile-O-Meter which was just a color coded vacuum gauge. They are pretty sensitive to throttle movement so they do make you aware of how hard you are working the throttle. Not as sensitive as a modern MAP sensor used on many speed-density type systems. 

  • Thanks 1
Link to comment
Share on other sites

On 2/6/2018 at 3:39 AM, Old Man Jimbo said:

You are absolutely right John although it makes a good discussion .I suppose I brought it up because it's natural for me to object when something is restricting me that I did not request. I'm a rebellious old fart.

Thus the handle " Old Man Jimbo ;)  "

Hey you got a point, anything new done was done outta curiousity or rebellion! And anything really is possible if you put your mind and money towards it ;)

  • Like 1
Link to comment
Share on other sites

H rated tires were the reason for the 125 mph fuel cut off. Is just one byte in the PROM. 2800 approaching 100 sounds like top gear, is faster a gear lower.

 

Am surprised how well it cruises at higher speeds since its life was spent under the double nickel.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...