Dyno-Jet....rear wheel dyno tuning.

History:
Last June I went and did a dyno-tune on my 96 LT1 (not stock).
Of course; on the way there the opti started playing out ...best I could do was 310hp at the wheel with an occasional 320HP spike, when the opti wouldnt act up.
My dyno guy Geoff stated: "LT1's like Magnacore wires vs. MSD's... or its the opti."
(I had new MSD's on the car)
I rebuttled with: "By the way its acting up in closed loop only, I think its the original coil or original  ICM..."

So...thats right, I changed the ICM and coil first...no change...
so...
 I think Geoff is on to something with Magnacore...so I buy and install those...still no change
But, I change the opti and all is good
I upgraded those old parts (I am sticking to that story)....Ok, OK, he was right!

Due to our hunting schedules and him opening the business, we dont get together until today.

So.....


Today We do a pull and.....276 HP ! ?????????

He asks: "where did you lose 40 HP?"

Me: "You got me, the car has been parked since Oct., I put fresh fuel, and a new lisence plate two weeks ago or so, and also all those new parts last July..
I also did a re-learn...this car should be roaring!
I havent put 400 miles on the car since last you saw me..."

He thinks for a minute, then he says something to me that; if I would not have seen all of this today, and been told to me by somebody else; I would NOT believe it.

He says:" I bet your MAF meter is dirty..."
(I'm thinking; yeah right, like thats gonna lose 40HP)

He takes the MAF (mass air flow sensor/meter) off the car along with the bellows, cleans the meter with Berryman B12 (carb, choke, TB cleaner), dries it off with air nozzle, blows the bellows and re-installs them.

Do another dyno run...308HP.....thats right...you read right...the MAF sensor between the air filter and throttle body got cleaned, did a dyno run and 42HP came back!.

Like I wrote above, if I was told this, I would NOT have believed it.
And I dont mean this MAF was caked with mud and dirt, I am taliing about a thin film of blackish/grey residue..like a light film of soot...he rubbed his thumb on the poles and showed me.

He came back with the Berryman TB cleaner did the TB and blades did another dyno run; I am at 321HP...he tweaked timing and fuel...ran a solid 330 HP at wheels on two easy/steady pulls...
HP raised  a little on other runs while tweaking looking for a knock (faulty knock sensor found), but for the sake of running too lean or too much timing, we left it medium.

He also used the tranny kick down to 2nd gear and spiked up to 406HP@ 6kRPM's.
He also got a kick out of all this using a 2.59 gear ratio at the rear...his dyno runs on my car were steady at 165MPH in 3rd gear...

So; the point of all this is...keep your MAF and TB cleaned and shiny...I am using the stock GM TB and MAF.
On the way home; 32 MPG @ 68MPH...yep, turning 1800 RPM's.

This thread could of went in electrical, fuel, exhaust, or tuning....Its in General because the littlest thing like keeping these metering devices clean can make a huge difference.
I have the dyno runs to prove it....and believe me, I will clean them on every vehicle I own now that I see how so little can do so much.



Your PSA for Today!



Jim

That tiny little wire is very sensitive to foreign matter. If you have a K&N filter, or other type that requires oiling, that stuff will eventually wind up on the sensor wire...as does just about anything else that makes it past the filter.
Glad the guy got it figured out.

That's good info. I would have never guessed that it would lead to a 40 hp reduction.

[QUOTE=Adams' Apple]That tiny little wire is very sensitive to foreign matter.
Glad the guy got it figured out.
[/QUOTE]

Was the first thing he went to...all was done in a matter of 5 minutes or so.
Yep the little tiny wires I knew all about, what got me is most of the debris was on the poles, not the wires.
And the poles have "channels" which fill up with soot and debris...all looks like its done though electrolysis. ..like powder-coating before it goes in the oven.

The MAF meter has to keep cool, the debris insulates heat on the poles and wires, which in cause gives the computer false signals, usually a very lean mixture.

[QUOTE=Gooch]That's good info. I would have never guessed that it would lead to a 40 hp reduction.[/QUOTE]


Me either Gary....never...maybe I would of bought in 10 or so, but not 42.
I just did my truck (check for soot) and it was dirty too...cleaned it up...I was occasionally getting a code 0171 and 0174 (lean left or right bank), and I believe I just found the culprit.





Jim