I went and had a new baseline dyno done on the same dyno as Rob and Marc. This way we can compare apples to apples from the same dyno operated by the same person.

This place is much, much better than the "other" place I first tried to get a baseline dyno. This one is very credible.

My car, with 54,ooo miles on the supercharger is currently running only 9.5 max psi boost and Rob, the very pleasant and knowledgeable fellow who runs Dietsch Motorsports estimated my current stock flywheel HP at about 348, which would make sense given I am 2 lbs down on boost from the 11.6 that is claimed to produce 370 flywheel HP stock.

Please see the attached pics of the readouts of the dyno results including the air/fuel mixtures. Notice the air/fuel WITH the meth/water injection is running a very nice 12.1-12.2 and 13.0-13.1 without the meth/water injection. It seems the car, even at only 9.5 psi of boost (running 91 octane and about 75 degrees F) was already backing off the timing as the meth/water injection at a rate of 350 ml/minute gave an additional 5.7 rwhp even at this reduced boost pressure. I'm convinced the water/meth injection will play a much larger role in lessening detonation as I increase boost to 15+psi.

Rob tells me that we can multiply these numbers by 1.22 to estimate what the "more optimistic" dynos would report, like a dyno jet.

The cost for this dyno is $75 if you do it during a Cars and Caffine event, but he is offering a 3 pack $90 each if you pay for 3 dynos up front and then you can do them whenever he has more time and attention span to offer more help tuning. The regular price is $125.

I am super impressed with this place and Rob himself, so I give them my highest recommendation.

Attached photos below
only the 3rd (and highest) run had the water/meth injection switched on.

My first mods are going to be a newly developed and never before seen full freer flowing exhaust and a new never before seen secret "stealth" cold air intake that has just come out of the ultra secret R&D section of Muppet Labs. Yes, I have those level of connections

As promised, I will dyno and post again with:

1. everything stock, but with the new exhaust so I can show the gain of just the full exhaust system

2. then adding the "Stealth intake kit" to the exhaust so I can show that gain individually too.

After posting the actual results of these two planned modifications all the rest of the companies who do not post actual dynos will either have to put up or shut up. I think the new designs will prove to be the best that there have ever been for the XJR. I will elaborate more after the mods have been installed and the accompanying dynos are posted.

 

good post...........watching with interest

 

Muppet Labs????? must be new never heard of em but as long as they take care of you then you should be happy. Much nicer dyno results and more along the norm subscribed

 

You will likely be hearing more about "Muppet Labs" as they are "borrowing" lots of your ideas and tweaking them just a little bit more. So far there are no less than 2 never been better designs just finishing R&D and should hit the dyno in a few weeks

Like Newton said : "If I have seen further it is by standing on the shoulders of giants."

So that being said, you have a muppet on your shoulder.

If you want more details, PM me and I will return some of the favor of your help over the past months

 

The Dyno runs as such may be ok, but the results to the wheels are way too low for a stock car.

Your car isn't optimal for the moment, so not a good time to start modding, as changing something now could alter what hasn’t been right, and you get false results, which I take you want to avoid.

So 2 things, find out why you run low on boost, and just as important, why you are so lean which isn't normal as well. Then re-baseline and start modding.

 

That would be in kW's?.

Oops no I seee on the charts that it is hp.

That's only about 190 kW.

Something couldn't be right?

 

AVOS, The superflow is known to read low. Your car "stock" ran your quoted 337 rwhp, this is just proving my theories that dynos differ too much to be taken as proof of any absolutes. Yes they are the BEST at proving gaines/losses under similar conditions on the same dyno under the same conditions, blah blah, but they are ***** for absolute numbers.
Rob did, I think, correctly estimate my flywheel HP at 348, which would make sense with being 2 lbs down on boost.

As reported in my above post, he said to multiply these results by 1.22 to get the numbers that would be reported by "more optimistic" dynos. Remember, this car ran duplicate 13.8s as it sits right now at 4100 lbs. So the 267hp x 1.22 would equal 325 or so on something like a dynojet. So the actual performance matches the above numbers. I'm not into mental masturbation over dyno slips. I only care what really happens on the road.

The reason I'm using, and going to continue to use this dyno place, is that both Rob E. and Marc used this dyno, and we all are going to have different mods, so we can compare apples to apples. Also, the Rob that owns the place has a very good set-up and can interrogate the computer during runs to find out injector pulse width, etc. and help me tune better. I feel I'm in good hands there.

The supercharger is tired as it has 54,000 miles on it and virtually no coatings left on the rotors, so the tolerances are not as tight as new. Id like to see a photo of a single 4.0 (not 4.2 with larger stock lower pulley), but 4.0 showing more than 11 psi at full boost.

Finding out why I am running lean is very good advice. It is still possible it had a tune in the past. As I make my mods I will keep an eye on the A/F ratio. I personally like the 12.1:1 range. What do you think would be ideal?

The most important thing for me is to see the difference each mod makes, and what actual performance times the car then delivers. My goal is to uncover the truth and make that available for others on this board.

 

 

Yes, you nailed it.

That is the lab

 

Your car should have about 370 BHP and a drivetrain loss of about 17% (possibly even a little less). So a dyno that can read rwhp properly (so at least has only 1 large drum per wheel), should read about 307 rwhp. This is also what I have seen on other cars, including mine when it was stock.

Can you post the dyno results of Rob and Mark? Where they there at the same time?

 

That video was awesome I think your in ummmm good hands just when they get done with your car dont forget to plug it in LOL.

 

Here you are: see attached pics of dynos
Marc's has a 1.5 pulley and x-pipe from mina, muffler deletes
Rob's car is stock, but was having some issue...I'll see him in a few hours and ask him then what that was.

Your saying these should all read approx 307 stock, but yours you said in another post yours stock read 337, so does that not suggest your dyno was incorrectly reading 30 hp (10% too high) ?

Please correct me if I am wrong on that and explain why your stock dyno is reading 30 hp higher than what you said everyone elses stock dyno should read, because that seems like pretty clear evidence of a falsely high reading.

 

That’s odd, he has a 4.2, then a 1.5 psi pulley anda different exhaust, so he should have about 30 to 40 rwhp more at least.

Was his car in tip top shape? Do you have the a/f ratio for his dyno?

 

I don't have any more information, but I will try to get it for you

 

You want to prove something, so you need to establish a good base for yourself.

So yes I am always interest in dyno results, but here it's more important for yourself to learn imho, so it's not needed for me.

 

I already have a good baseline. The 348 flywheel hp Rob gave me from this last dyno is very logically accurate and jives with the 13.8 at 101mph 1/4 mile time with no traction issues. This jives with the reasonable performance calculators. I don't need to prove anything else, it has already been proven.

370 stock -2 lbs boost = 348 flywheel HP. Nothing is a mystery here.

I can't speak for Rob's and Marc's cars, but mine is right on the money except for the worn super charger, so I am ready to start with my mods. Maybe theirs are not, but mine is and mine is the only one I am relying on.

Now when I test my mods, first exhaust, then add intake I will see the individual gains. Using the same dyno with the same skilled operator will give me credible, reliable numbers for my gains. Since nothing else will have changed other than the modification(s) being tested the gain in HP will clearly and obviously be because of the mod. No one will be able to argue any different.

This is very simple stuff.

 

All in all it is simple, the hard part is to take out assumptions.

Keep an eye on your mixture, if you can't fix it, at least keep on measuring to avoid results being affected by changes to the mixture.

 

That's some serious drop in the power during the climb. Almost looks like the engine pulling timing due to knock. Would be interesting to see timing shown alongside the power curve.

What dyno were these pulls made on? Mustang or Dynojet?

 

These were all done on the same "Superflow" dyno. They read quite a bit lower than the Dynojet or Mustang dyno. The operator said to multiply the Superflow result by 1.22 to approximate what a Dynojet would read.

I'm certainly no expert, but it looked to me, by the curve, that it would likely be the restricted intake and exhaust being the limiting factors at this point (stock)

 

No. If it were an air flow issue, this would get worse at higher rpms since the engine requires more air with higher RPM.

Most likely it's either long term knock, if it repeats on every pull, which can be usually cleared by disconnecting the battery for 30 or so seconds or short term knock due to cheap gas or fouled up spark plugs.

Tom