Escalade 345Hp 6.0L fact or fiction

Tjwong · August 27, 2003

I was messing around with my friends new 2003 1500HD with a 300Hp 6.0L the other day trying to figure out what is the difference between a 345Hp version of the Caddy Escalade engine. I went to my friends GMC/Caddilac dealership to explore the diffrences in engine parts. Low and behold after comparing the engine parts between my buddys truck VIN and a new 2003 Escalade VIN (GM dealerships parts PCs now reference all parts via VIN) I could not find a single difference in engine parts. Not even the air intake, air filter housing nothing was different. Even the PCMs are the same parts.

So where is GM getting this 345Hp from? Is it engine calibration where the difference lies or is it in the exhaust system? The one thing that is different is the exhaust, but that is because my friends truck is a PU and the Escalade does have different exhaust systems. I don't know if the Escalage system is free flowing enough to give a 45Hp gain over the standard truck engine.

So later this week I will flash my friend truck with a 03 Escalade calibration and go from there. It is either in there or GM has rated this engine with different test standards as a marketing ploy! If they did this it is not quite lying but it's not quite on the up and up either!

1BADHD · August 27, 2003

It has a different cam profile and higher compression ratio.

Tjwong · August 27, 2003

Not according to the parts books, all engine internals, including heads, valves, camshaft piston rods and cranks are all common to the 6.0L engine. Beleive me I checked everything in the GM parts computer.

gmcjoe · August 27, 2003

It has a different cam profile and higher compression ratio.

There are a few different parts in the 6.0 engines

Cadddy Escalade - 345 HP LQ9

GMC Denali - 325 HP LQ4

Hummer H2 - 316 HP

2500+ HD Trucks - 300 HP LQ4

Funny part is they call both the 300 HP and 325 HP engines LQ4...that is odd...

rico750sxi · August 27, 2003

I think the LQ4 ratings are different because of exhaust/intake differences between Hummner/HD/Denali.

This is interesting about the part numbers, I have an SS so...

1BADHD · August 27, 2003

Are the head casting numbers the same?

Tjwong · August 27, 2003

I have all the part numbers for cam, heads, etc etc if anyone is interested. and from what we found in the GM parts system all the parts are shared between all truck lines including the Escalade. If someone has other part numbers please by all means chime in.

The intake plenum, air filter box and the intake plastic runner from the air filter housing to the throttle body are the same for the Escalade and the PU. It maybe different for the H2 Hummer. But for all CK trucks it is the same.

I will be flashing his PCM this weekend with an Escalade calibration to see what that does.

04GMC8100HD · August 28, 2003

I believe it all in the PCM tune. I talked to dave henninger of Wheel to Wheel performance, they do alot of concept vehicles for GM, and he said that they had a 6.0 making 400 hp with just there pcm tune. Now of course that's probably a max effort and GM would probably be quite pissed if he were to distribute this info since they paid him to do it.

Randy

Tjwong · August 28, 2003

Here is a link to an LPE ad on EBay where they are selling some take out cams from the LS1 engines. This cam GM Part number 12561721 was used in most all LS1 engines including the Corvette and F body LS1 engines, as well as all LS1 engines for the truck lines including the Escalade:

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=33614

It is a pretty whimpy cam with the following specs:

Intake Exhaust

Lobe Lift .274" 280"

Dur @ .050 197 207

Lift 1.7 ratio .466" .476"

Separation 115.5 115.5

Its gotta be either a marketing scam or there is some real PCM tuning that is combined with a lower restriction exhaust that gives the Caddy those extra beans. I will be flashing the PCM this weekend given my last SPS update contains the valid new calibrations for the two 2003 model trucks VINs that I have to use. Otherwise I will have to wait until my next TIS upgrade comes in from GM Techline services. In anycase seeing how I have started something I will keep all of you posted.

Dihappy · August 28, 2003

So how will you verify the upgrade?

Are you going to Dyno his truck?

Tjwong · August 28, 2003

We are going to do a before and after run on the dynojet down the street from our shop. Plus the good old Butt Dyno as well if you now what I mean

DOGMAN · September 1, 2003

WELL???

mmayo · September 2, 2003

Still waiting.......

mmayo · September 9, 2003

So are me and DOGMAN the only ones who wanted to know how this turned out? Tjwong, where are you? Let us know how it went !

speedshifter · September 9, 2003

I work at a Caddy dealer when I'm not in school. I have never gone and investigated how the Escalade gets its extra HP, but its definately there. Its noticeable between the H2 and the escalade.

It would be interesting to find out what makes the difference. My dad is a GM Master Tech there, so I will call him and see what he says.