They are S&P headers. Hard to believe they'd cause a 50rwhp difference, that's huge. Cats may be causing a 5-10rwhp change, I've dynoed cars with and without cats (using the factory restrictive cats) and that was all the difference was.

Why would the fact that an F body has a live axle make a difference in the whp?

The red lines are my final graph and A/F, and it's at 13.0-12.8, definitely not rich. The first run in blue they were too rich.

My suspicion is the cam timing. I know they didn't use a degree wheel when they put it in, just installed it and lined up the marks on the timing gear.

I'm going to take it to a local shop (that also has a dynojet) and let them look over it. Local CMC/AI guys have put 350rwhp down on their bone stock LS1's...

 

Over the years i have had cars on litterly dozens of dynos both private an public. Same car, same week, same city, same tune different dyno more that 30 hp difference. Most are "optimistic" to say the least.

For christ sake quit bench racing and go race the car. If you feel compelled go get it dynoed at a local non biased shop. I would bet $1 it will be different that it was in Texas.

 

I know HP was not the limiting factor on my lap times.

 

In my opinion your setup is not going to make 385whp in a 951. I assume that's your expectation? The Garcia car does, but every other swap with similar mods doesn't. The live axle has less drive train loss than the torque tube/transaxle. Lining up the marks is usually very close on the LS1 and so I doubt you will find 50whp in degreeing it.

BTW, a bone stock LS1 will not dyno 350whp unless the dyno is rigged....not even using STD correction factor.

 

I agree that on differences between cars, but not 50 hp at the wheel difference on "like" setups. I'm only chiming in because his setup is almost identical to my setup and we have a 50RWHP difference.

And as far as dyno accuracy goes... I won't debate that. But I can tell you I race against cars that weight within <50lbs of mine, we both dyno out (on different dynos) within <15RWHP and we are dead nuts even coming out of the corners and down the long straights.

So I believe that my LS1 was pretty darn close to the 390RWHp mark as the dyno indicated.

The question is... why is doc's not.

TonyG

 

I don't necessarily expect to make the same ~390rwhp that Tony does, but I find it odd that I'm not making ~370rwhp.

I'll take it to my local dyno and run it, guy there is also an LS1 tuner and have him take a peek at it.

 

Lets apply the time tested Ricanomics factor to the situation:

Dyno Differences + Emissions + Cam Differences + TGBCF = Difference

20+ 15 +5 +10 = 50

WTF go drive it!



PS
My Super Duty 250 tow rig makes 382 RWHP and 591 RWFPT one of my race cars makes 385 RWHP and only 372 RWFPT. Same displacment within 2 cubic inches. Where is the other 219 FP?

 

I appreciate what you're saying, but I think you're missing the point. The cars are the same, motors are the same, with substantially the same setups. Regardless, the car is going on a local dyno this coming Friday and will get looked over. If all is well, it is what it is and I'm happy with it.

 

As my project is at a standstill I am living victoriously through you. Upload some video and sound clips, please. Couple of questions, how much was the turn one power steering pump and how is the braking/steering?

 

Working on it right now. Uploading to YouTube takes forever!

I'll have some shorter videos and sounds clips by the end of the weekend...

 

Holly Sh-t.... 50hp can be a difference in ignition timing, fuel ratio, and slight difference between dyno's. Not a big deal... Lets see the ignition maps between both cars.... Maybe they put a "safe" ignition map in Docs car.....

 

Pulled the codes today. Got a P0155, O2 heater circuit Bank 2, Sensor 1. So not sure if that means automatic replacement of the sensor?

 

is it hidden in the diesel?

 

Hey Doc - good to fine tune and review your setup, but as a few have mentioned, dyno is a tuning tool only. Unless both cars are dynod on the same dyno on the same day, with the same operator, I would not even give a thought to 50 hp difference.... it's just an internet dick measuring contest

Now go beat on that thing and see what you really think.

 

Yes, replace it.
No, it probably won't add 50 hp.