: Computer programmer



Dadillac
12-26-04, 08:36 PM
Since I am new to Cadillac (GM) ownership, I have a question. A lot of companies put out programmers, for many Fords, Dodges, Chevys. Is thier one for Cadillac's? My '02 SLS is just begging me to install a few more horses under the hood. I checked Superchips, and Hypertechs websites, but didn't find anything. Please direct me to a company (if there is one) who can help me. Thanks in advance

Don

BeelzeBob
12-26-04, 09:13 PM
I don't know of any source or reprogramming or re-flashing the PCM for your car. Be careful if you do contemplate it as the PCM's can be brain-deaded very easily....very very easily.

There is no real power or performance to be had with a simple "reprogramming" of the computer for that model it that helps any....the engine is calibrated for best power with full MBT spark and the correct fueling. Granted, with cam changes and such a recalibration would be necessary/helpful but with an otherwise stock Northstar a "chip" is basically going to do nothing.....

On some older packages and other brands there were some engines with relatively conservative calibrations that could be "improved on" for power with more spark and fuel but the Northstar line has been calibrated very aggressively for maximum power from the beginning. That is one reason they make over 1 HP per cubic inch from the factory.

Dadillac
12-26-04, 09:18 PM
Thanks Bbob. I guess that this is a good thing. Every vehicle I have had, has always responded reosonably well, to reflashing. It is comforting to know, that noone makes a programmer, for no gain. Maybe I can figure out a freer exhaust, without being louder. Now that is going to be a challenge.

Don

BeelzeBob
12-26-04, 09:48 PM
Yea...a reflash is the last thing that I would personally do to one of them if it was mine.

They do like less backpressure.....check out the exhaust system on a GXP Pontiac Bonneville. It has SUBSTANTIALLY LESS backpressure than the production Cadillac systems and is quiet with a pleasant burble on decel and a light to mild tone under load. Cruising it is transparent. No annoying drones or moans. One could be converted to an SLS quit easily me thinks. An OEM GM exhaust system is not necessarily the cheapest option but it is sorted out, free flowing and quiet....if you take into account changing many mufflers and such it is not that expensive maybe.... There is adequate fuel and the appropriate spark in the OEM cal for the exhaust change.

The other biggie for out and out performance (which is what you are after...) would be a looser torque converter. If you have Yank make you one it will still lock up normally and have the same highway fuel economy but will launch the car much better.

Dadillac
12-26-04, 10:00 PM
Thanks for the tips. Who, or what, is Yank? My experience with torque convertors, is that the more agressive you go, the less reliabilty you have with the rest of the trans. It sounds, like the convertor you are speaking of, is very mild. Also, can the trans and engine be seperated, without going through hell, and still do it in the car?

Don

BeelzeBob
12-26-04, 10:29 PM
You can go with a 3000 to 3500 stall speed torque converter that is still reliable and streetable in that car.

Dropping the trans in a FWD car is not simple or easy....you hang the engine from some beams across the engine compartment and then drop the trans...or just have a shop with a hoist drop the whole cradle and then separate them. Granted, not the simplest mode...but the most bang for the buck, period.

Search in the forum search feature for "torque converter" or "high stall" or "yank" and there are a bunch of past posts

elwesso
12-26-04, 10:43 PM
The reason that there are upgrades for OBDI cars and not for OBDII cars is there is not as much room for improvement in OBDII.. OBDI is a slow system, as some saftey factors have to be built in.. Not as much the case on OBDII, since it has faster acting computing power as well as more sensors, there isnt the need.....

Bob.. I drove a GXP the other day, and I was impressed... Its a nice car, however, the higher rear end kinda makes it feel bigger than it really is..... I like the car, but we opted to get a new pontiac GTP with comp G.. The new northstar looks really nice, hopefully they did stuff to make it more reliable, even though its a pretty kickass engine to begin with... The northstar is one of the smoothest V8s ive ever been in... however it was a litlte low on power, but it only had 38 miles on it... The car was not as fast as my slightly modified Q45, but thats probably because it wasnt broken in yet... All in all, i think GM did a good job on this car!

BeelzeBob
12-27-04, 12:18 AM
The reason that there are upgrades for OBDI cars and not for OBDII cars is there is not as much room for improvement in OBDII.. OBDI is a slow system, as some saftey factors have to be built in.. Not as much the case on OBDII, since it has faster acting computing power as well as more sensors, there isnt the need.....

!


OBDI and OBDII really have nothing to do with the engine control itself...it is strictly about the onboard diagnostics systems. OBD2 requirements commonize the onboard diagnostic requirements and readouts per the Federal requirements as established by the EPA. There are also requirements with OBD2 regarding tamper resistence and such.....that is why manufacturers are very secretive and selective with the OBD2 systems as to who knows how to "program" them and who doesn't.

While it is true that most OBD2 systems have faster computers and some have more sensors that is really more to do with the evolution of the engine controller technology than any requirement of OBD2 or how the engine might be calibrated. Since the OBD2 requirements specify what engine parameters and engine failures require diagnosis by the onboard system there was a great deal of software added to the control algorithms for this....so it was "convenient" for manufacturers to roll out the faster computers concurrent with the 96 model year and OBD2...but that didn't really affect how the engines were cal'd and how close to perfect the engine power cals were. The faster computer power was mostly used to satisfy the additional diagnostic requirements...not change engine power or cal accuracy.

elwesso
12-27-04, 11:00 AM
You know bob, to be honest, i made that post so that you might say something to the indifferent :) ... I was a little sketchy on those details..


So for the record, there should be no performance difference between a 95 and 96-97 northstar...?

Its kind of interesting, because on the Q there is real power to be gained by getting an upgraded chip.. IT leans out the mix a little and advances the timing somewhat... As well as raising the redline and removing the speed limiter :)

BeelzeBob
12-27-04, 09:39 PM
So for the record, there should be no performance difference between a 95 and 96-97 northstar...?

Its kind of interesting, because on the Q there is real power to be gained by getting an upgraded chip.. IT leans out the mix a little and advances the timing somewhat... As well as raising the redline and removing the speed limiter :)


There is a tiny difference but it is not because of OBD2.... The 96-99 Northstars had a MAF and the PCM mounted in the air cleaner (underhood). The added inlet restriction of the MAF and the more convoluted ducting of the intake system with the PCM in the air box (to cool it) takes a couple of HP but not enough to notice....but technically it is there.

The timing in the Northstar is set for maximum performance. If it detects detonation it will retard the timing to protect the engine which causes a little power loss. But the "fix" here is to run good fuel...not change the chip.

I agree that the speed limiter can be eliminated with an aftermarket chip but that is really not possible on the OBD2 cars without a lot of difficulty.

Leaning for more power....possible...but do you wonder why the factory has that "extra" fuel in the cal...???? It is to protect the catalytic converter from overtemp under heavy load and to protect the pistons and spark plugs from overheating and damage/preignition that would result in catostrophic engine failure. The extra enrichment in a Northstar only comes into play after 20-30 seconds during extended full throttle operation. On a quick runup or blast down the dragstrip there is no extra fuel to remove....