My SHO is a slug!!

[bigbadfords]

Does anyone have any ideas on why my sho seems to be slow and low on power at lower rpms?? Once the car's rpms get higher the car takes off and actually feels like a "fairly fast car" and running with the power it should have, but at lower rpms it just seems so sluggish and slow, this is my first sho and I've had it for about 4 months now and its been like this since day one, so maybe these cars just arent as fast as I expected them to be?? Trying to figure it out, the car has no miss, idles smoothly, has new fuel filter, new crank sensor, cleaned egr and throttle body and have the secondaries wired open. Any other suggestions would be appreciated. Thanks guys

 

[luigisho]

Secondaries open down low doesn't help but these things are kinda dogs at lower rpm anyway. Tranny is mushy too and that doesn't help either. Most of the good stuff is at high rpm.

 

[biker889]

yeah ummm..having the secondaries wired open is going to cause that....

 

[bigbadfords]

yeah ummm....it was like this before I wired the secondaries open, if you read the post I already said that it was like this from day one....before I wired the secondaries open!! Thanks for your input luigisho, maybe there is nothing wrong with my car if you are saying these cars are kind of dogs at low rpms, and I have to agree with the tranny statement also.

 

[Vnuk1]

It's a V-8 of course it's a dog. Should have bought a Gen II Mtx if you were looking for something a little snappier off the line..

 

[Sam]

other possible causes

air filter; weak spark - spark plugs & wires, coils, alternator; brakes dragging; low air pressure in tires

 

[biker889]

yeah ummm....it was like this before I wired the secondaries open, if you read the post I already said that it was like this from day one....before I wired the secondaries open!! Thanks for your input luigisho, maybe there is nothing wrong with my car if you are saying these cars are kind of dogs at low rpms, and I have to agree with the tranny statement also.

You never specified that YOU wired them open...My point is we cannot help you diagnose a problem if you have something done that will obviously cause what you describe.

 

[illSHOyou]

Wiring the secondaires doesn't do ****...

 

[TopGunnYFZ]

Its a Gen 3 whadya expect? Lol jk or am i?

 

[stephen newberg]

You never specified that YOU wired them open...My point is we cannot help you diagnose a problem if you have something done that will obviously cause what you describe.

This and the previous quote to the same effect by this poster is simply wrong and should not be relied on. In the Gen III wiring open the secondaries does not cause any decrease in power, at the low end or anywhere else. This has been pretty completely documented and there would be foundations for such both in older threads here and over on V8SHO.com.

As per the rest, the design of the power curve for the Gen III is not such that it will ever be a stop light racer. As someone else noted above, if you want snap speed from a standing start, you really need a Gen II mtx which was designed with that in mind. The Gen III is very muscular at higher RPMs and when powered up as a roll on rather than from a standing start. The intended uses for the Gen I/II and Gen III were very different when the designers were putting together their performance characteristics.

pax, smn

 

[sperold]

Do some times for 0 to 30, 0 to 60, and whatever else you can think of, and post them here.
It may not be as slow as you think....
or....
It may be so slow that something must be really wrong.

Look into a test to see if your cats / mufflers are plugged? Could the cam have moved a bit before it was welded?
I would do the codes and see if anything is wrong.
How is the gas mileage?

Have a look at this: http://www.shoforum.com/showthread.php?t=49023
As you can see, the Gen 3 SHOs are not so doggy after all, as the top 3 fastest automatics are Gen 3s.

 

[biker889]

From V8sho.com
Description, Operation, and Replacement
The air induction system improves engine performance by using the intake manifold runner control (IMRC) assemblies as follows:

The intake manifold has two runners per cylinder, feeding each of the intake parts in the cylinder heads. The IMRC assemblies are located between the intake manifold and cylinder heads, providing two air passages for each cylinder.

One air passage is always open and the other passage switches from closed to open by means of a valve plate. Below 3000 rpm, this valve plate is closed to improve low-speed and cold engine performance. Above 3000 rpm, this valve plate opens to improve high-speed engine performance. This is what you hear as your car hits 3400 rpm's; the "secondaries" open up. If you can't hear this on your car, and your SHO seems a bit slower or sluggish, your IMRC deactivation motor may be damaged. It will need to be replaced to bring the SHO back up to speed again.


Out of the 5-6 topics for them, only one has comments about it not changing.
which is here
http://www.v8sho.com/SHO/IMRCAutopsyFindings.htm
and it still goes both ways...until i see true dyno numbers either way, im sticking to it. No need to say that im "simply wrong" wheres your proof im wrong?
When mine were stuck open in my STOCK 96' i felt a difference, hence the reason i tried to assist the OP.

 

[Funmart6]

It has also been said, that the refined nature and smoothness of the gen3 makes it feel slow when in fact it is a fairly quick car. Keep in mind also that this car was designed as a fast and stable interstate rocket, not a drag racer.

 

[bigbadfords]

Ok guys, I will not say that anyone is right or wrong on this matter but from my own experience with this car I didn't notice a bit of difference after I wired the secondaries open compared to them not being wired open, the car seems to run EXACTLY the same both ways, weather running at idle or high or low rpms, my personal experience is that wiring the secondaries did absolutely nothing (negative or positive) for my sho. Secondly my gas mileage is fairly bad (usually around 17 mpg avg) and I should mention that the car takes off and runs like a champ once the rpms get around 3100+, just below that range is when I have this doggy feel to it. Anyone think a plugged cat could be a possibility? doesn't a car usually run worse at higher rpms with a plugged cat though?? And as sperold said above, could a cam that has moved just a bit before being welded cause these symptoms?? which is basically saying that the timing of the car is off just a hair, correct?? Thanks again for all replies

 

[luigisho]

They are dogs down low. My car has never had good low end torque. However there have been 1/4 runs where the GenIII is close to the other models. Other than that you could have a slipping tranny issue. Hard to tell without comparisons to other similar cars.

As for the mileage, I get about the same as you. You car sounds like it runs alot like my car. I'd complain but my tranny has 192k on it and I just don't feel like putting much money into it at this point.

 

[MARV87341]

My v8 sho is a slug

Get out while you still can. It's too late for the rest of us.

 

[bigbadfords]

It's now too late for me as well.....tranny just went earlier today, wont move in any forward gear, but reverse is fine. Thankfully the car is still under warranty since I purchased a 7500 mile warranty with the car, I also have a 97 parts car with a perfect tranny that only has 43K miles on it. Warranty should cover it, I will only have to pay the $100 deductible if all goes well. I really like my sho and I hate to say it but, this car is BY FAR the most unreliable biggest POS that I have ever owned in my life and it only has 125K on it. I have only put a little over 3K miles on it so far in the past 4 months and it has had a brake line blow, abs sensor go bad, ball joint break, axle whiped out, spindle broke, and now needs a tranny, and its not like the car has 200K miles on it, these cars sure aren't one of Ford's best in terms of quality and reliability!!

 

[SHOZ123]

From V8sho.com
Description, Operation, and Replacement
The air induction system improves engine performance by using the intake manifold runner control (IMRC) assemblies as follows:

The intake manifold has two runners per cylinder, feeding each of the intake parts in the cylinder heads. The IMRC assemblies are located between the intake manifold and cylinder heads, providing two air passages for each cylinder.

One air passage is always open and the other passage switches from closed to open by means of a valve plate. Below 3000 rpm, this valve plate is closed to improve low-speed and cold engine performance. Above 3000 rpm, this valve plate opens to improve high-speed engine performance. This is what you hear as your car hits 3400 rpm's; the "secondaries" open up. If you can't hear this on your car, and your SHO seems a bit slower or sluggish, your IMRC deactivation motor may be damaged. It will need to be replaced to bring the SHO back up to speed again.


Out of the 5-6 topics for them, only one has comments about it not changing.
which is here
http://www.v8sho.com/SHO/IMRCAutopsyFindings.htm
and it still goes both ways...until i see true dyno numbers either way, im sticking to it. No need to say that im "simply wrong" wheres your proof im wrong?
When mine were stuck open in my STOCK 96' i felt a difference, hence the reason i tried to assist the OP.

I made 207 HP on the dyno with the secondary plates removed completely.

And the V8 does not have two runners per cylinder. It has a separated intake valve port where the secondary valve is isolated from flow coming in from the common runner for that cylinder.

The V8 PCM programming is smart enough to learn and correct the cold start issues in a few drive cycles.

But it will have no affect on power as the only time you would be at WOT and below 3400 rpm is in 1st gear and the time below 3400 rpms is minuscule.

And indeed if the runner is stuck closed then that would definitely choke the life out of the engine. Easy to check. Just spy the linkage behind the TB and goose the motor WOT from the TB. The secondaries should open and close.