Swap LA1 with LX9 or LZ4
 

I read here about doing a simple LX9 top swap on an LA1. I think a top swap would be ideal for me, as it would increase power, and (according to other online sources) slightly increase mileage. Which is what I will do short term.
I was thinking, when I get enough money together, maybe swap for the LX9 altogether ( I know some adaptations would need to be made), or maybe the LZ4 (3500 vvt). The LX9 swap, with adaptations seems easy enough. But what of the possibilities of swapping the LA1 with the LZ4? Again, adaptations would need to be made, but I think may be a possibility.

What do you all think?

I am pretty sure the LZ4 will not work because of the vvt. Variable valve timing. The alero la1 or the lx9 do not have it. just find a low mile lx9 and swap it in.

If I went with the LZ4 swap, wouldn't the main things be wiring and a PCM? Other things too, I know. But wouldn't those two be the main things?

I had talked to milzy at one point when he was looking for someone to volunteer there car to get a 3900vvt swap and he said that because of vvt with that the two options were to rewire the car because nothing would work with it or to remove vvt from the motor which requires rebuilding the motor and changing components

LX9 + port work and a cam would be cheaper and produces a considerable amount of horsepower. Anything else with VVT will be a road of hardship because it hasn't been done.

Well, my short term is definitely an LX9 top swap.

If I swap for the LX9 altogether, would I need another PCM, or can I just get the one I've got reprogrammed?

LX9 swap can run off of the LA1 PCM tune no problem, but it is strongly recommended to get a tune to see optimal results. I would also recommend larger injectors though which would absolutely require a PCM tune. Easiest injectors to swap on a 99 alero in would be the GTP 36# injectors because they use the same plugs, but they are a bit overkill for a stock LX9.

See link below:
http://dl.dropbox.com/u/534555/3500%...dy%20Swap.docx

Hmm, might just stick with the LX9 top swap then.

For just the top swap, would I need the new injectors? I can see using new ones for the best performance.
Then what of tuning? Is there a simple chip for it, or would that be something best left to a pro shop?

For the top swap you may want upgrade injectors, but it may not be necessary. The 99s had smaller injectors than the 2000+ models. On the 3400 when I did a wide open throttle pull, my stock 22# injectors reached a duty cycle of 75% at 5600 RPM. With the cammed LX9 + 28# injectors, I reach a duty cycle of 70% at 6500 RPM. The duty cycle is essentially the on/off rate which can be thought of the load being applied to the injectors.

Tuning wise your car works with OBD2. Which means there are absolutely no "chips" made to work for our cars. Anyone who tries to convince you otherwise is a moron and doesn't know any better. HPTuners is the only tuning suite readily available for our PCMs at the moment. If you can find a DHP PowrTuner that is also an option, but is slow as hell because it uses RS-232.

Tuning is something that can be self taught but it requires hours of researching, patience and trial and error. Doing an injector swap is one of the easier things to tune for.

That sounds like what I'll do then. Top swap with injectors and tuning.

What's a good place to look for the injectors?

What I would do is just pick up a set of junkyard L67 GTP injectors. You can probably pick a set up for around $60. Buying them brand new would cost you an arm and a leg. Next I would get them professionally cleaned and tested. They will test each injector's flow pattern to make sure they are all flowing equally. I've found prices for this service is around $20 per injector in the USA and about $30 per injector in Canada which is brutal!

Check http://car-part.com/ for 2000 Pontiac Grand Prix Supercharged injectors. The website will cross reference the part with other model years and vehicles. You'll be able to see which ones are the cheapest near you.

Probably just go to the junkyard, then.
Milzy also sells the 3x00 injector upgrade kit, but I could get them cheaper at the junkyard. Or, rockauto. I can get a set of 6 3800s/c injectors, reman, tested and cleaned, for about $35 each. So $210 for all 6, and they're up to spec.

Id want to go with the 3800 injectors anyway, with less to worry about in terms of fuel starvation.

There are also the 28# trailblazer Injectors which is what I'm currently running which would be more than enough for the 3500, but they're multec 2 style plugs not the Bosch style like what came in the 99 Aleros. You would have to get the injector harness from a 2000+ alero to run those though.

On the 2000+ Alero harness, is the connection opposite the injectors compatible with the connection on mine?

Uhh... What?

There are two sides to the harness. The side which connects to the injectors, and the other, which connects to the rest of the wiring.
Unless you meant to splice the new connectors into the existing harness.

Oh.. Gotcha. From what I understand, yeah the injector harness does plug in.

Found a tuner on autoplicity for $40 +ship. That, and I could get the obd 2 cable and plug it into my phone, download a tuner app and tune with my phone.

Probably just get the tuner, since its made just for that.

Yeah... I don't think that'll work. Most tuning suites cost over 10 times as much. HPTuners costs $500-650 brand new depending on which version you get. You're probably looking at an OBD2 scanner which doesn't help you out with what you need.

Here it is.
I saw some of the nicer ones, like with the wireless interface. Those were $400+. Some of the others were up there, too.