Mark VIII on dyno questions...

98LSC32V

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OK, how do you dyno a stock Mark VIII, I know you are supposed to dyno in 3rd gear which is the 1:1 ratio in the tranny but the speed limiter will kick in at 124mph or 130mph depending on if it's an LSC or base model. This won't give you accurate horsepower readings because you will be in 3rd around 4000rpm or so. Can you dyno in 2nd gear, how will this skew the readings? I actually like the idea of dynoing in 2nd gear in my 98 LSC as well since it is chipped and I don't want to take it all the way to 150mph+ on the dyno in 3rd gear at 6500+ rpm.
 
I wouldn't worry about the RPM on a dyno. I sit in first gear plenty of times through Houston traffic, it's a good brake when you let off. Sometimes I play with redline like a basketball against pavement. I have 132k, still doesn't burn oil.

I redline my car at least 15 times a week, sometimes in second gear when someone decides to play on the highway. Just chillin, 5k rpm and up. It's been 'abused' like this for the last 63k miles. I'm not saying it's ok, I'm saying a dyno run would be fine I'd think. Just make sure they have a good fan for you.
 
Post the results when you're done. I did my bone stock Mark VIII, and I'd like to know how similar the results are. Also, see if you can get the make/model of the dyno too.

Paul.

PS - Mine made 228 rwhp/227 rwtq
 
Well my 98 LSC isn't bone stock and it is a Mustang Dyno which reads lower than a Dynojet.
 
98LSC32V said:
I actually like the idea of dynoing in 2nd gear in my 98 LSC as well since it is chipped and I don't want to take it all the way to 150mph+ on the dyno in 3rd gear at 6500+ rpm.

Why? :confused:
 
It's hard on the car to take it all the way to 150mph...
 
98LSC32V said:
It's hard on the car to take it all the way to 150mph...

Not really. The dyno doesn't have near the amount of load as actually driving the car that fast.

What mods do you have?


I wrapped mine up the speed limiter on the dyno - it was fun. I have video. :D

Paul.
 
speed limiter is nothing. i hit the limiter in 3rd at least 3 times a week.
 
OK but my car has no limiter it will hit 150mph+ on the dyno and that will take a long time compared to a 2nd gear run...
 
Bah,


How fast do you think the 03-04 cobra guys are running the wheels up to in 4th gear? Just run er up. There is NO problem with it. In fact you don't even have to use your brakes. They dyno has em built in.
 
We ran mine up to 140 mph in 3rd gear, no problems even with 3:73 gears

Engine 1.jpg
 
If I want to dyno in 3rd, at what MPH should I go WOT at so I know it's in 3rd gear with overdrive off?
 
The chart is plotted against engine RPM. MPH is a function of total gear ratio,tire size etc. Your MPH is affected by all these. The motor above has seen 6900 RPM for a 140 MPH sprint.
 
Mine did the same with 327 gears and we had to do a 2nd gear pull (451 RWHP)
after I installed the 410 gears we were able to bring it over 7000 in 3rd gear and after making a custom 4" inlet pipe and adding 14% more fuel this was the result
494 rwhp
I didnt look at the MPH though
2449286_17_full.jpg
 
Am I understanding this correctly?

You're running 450+ HP and on a dyno and do not have the speed limiter removed via a chip or program?
 
Lidio said he was unable to remove the speed limiter through the PCM and I did some research and found the speed on the Gen 2 mark is taken from the front abs sensor and transmitted to the PCM through the ABS module.
When I installed the 410 gears, I didn't have to change the speed cal or speedo gear due to this pickup location
Has anybody else been able to disable the feature in the PCM?
 
Yea.......thats why I don't understand the issue. Jeremi (m-maker on this site) Has an eaton powered 97. I'm almost positive he has no limiter. Tuned my Lido at alternative auto as well.
 
Jeremi was at Lidios when I was there getting the tune
If he could have I am sure he would have removed the limiter at that time
 
I believe I have the top speed limiter removed in my 98 LSC with my SCT chip, I will let you know when I get my car dynoed...
 
Lidio can move the RPM limiter around as the software allows him to do it. He did it with mine, which is a Gen 1 car so there's no confusion. I watched the run and video taped it so I kow that the above data is correct. Hope this helps answer your question.
 
My brother Mike has speed limiter removed and rpm limiter moved to 7100 on his 98 blown mark LSC.It was funny when he put 4.10 rear end in it because the car was hitting speed limiter around 100 mph.He had it tuned by Sutton HP with SCT excalibrator 1.
 
Dyno = front wheels stationary.

I'm pretty sure that means on a Gen 2, the PCM thinks the car is sitting still.
 
You are correct, It must be the rear wheel sensor then????
I am trying to research a little more and will scan the speedo page from the Ford manual tomorrow.
BlackIceLSC said:
Dyno = front wheels stationary.

I'm pretty sure that means on a Gen 2, the PCM thinks the car is sitting still.
 

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