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Help me "reasonable-ize" my daily driver mod list.

R

rafadavidc

New member
First post, but I've been reading up on this engine for years and years by virtue of having owned two L67s since 2007. Yes, I've been through all the stickies. I'm thinking of pulling the trigger when the weather warms up, and I want to have the stuff and the plan good and ready to go. I keep running into the "If you give a mouse a cookie" problem, though, which I'll outline below.

There are two major complications to this project:

- The car in question is a 2004 Buick Park Avenue Ultra. The GM C Platform is very, very similar to the H Platform (Bonneville), but I'm afraid of differences in the firewall or undercarriage (for example) that would make things like headers or downpipes incompatible. An example that comes to mind - the Bonneville uses a different length supercharger belt than the GTP, and that seems weird to me, since it's the same engine. Also: wbodystore.com --> okay.jpg

- This is my daily driver. I would obviously do this over a weekend and probably take a few days off work as well. This complication is mitigated by a close buddy who is a certified GM mechanic. HELLS YEAH!

On to my mods list: Here's what I have in my ZZP cart so far.

- ZZP PCM - Because I'm probably not spending $500 on an HP Tuner, unless my buddy wants to do that, then I'd do like $200 of it and let him keep it. All options stock.
- 160* Thermostat - Because why not. All the reading I've done indicates the 2004s should have 180 or hotter, but I'm pretty sure that's for the GPs with the L32 motor. I have an L67 with a Gen3 blower.
- TR8 Iridium spark plugs - Because I'm not changing these damn things every 6k. For the colder thermostat.
- Power log and off-road down pipe - Fix the stupid U-bend (really, GM?) and front manifold; off-road because I can delete the O2 sensor code with the PCM and still pass emissions without a cat. I'd polish (and port?) the rear manifold myself. Decided on this combo over a set of Pace Setter headers for cost-effective solidness. Further, besides an incremental improvement, I can't really see what headers are doing for me over the combo of power log + polished rear manifold + down pipe. I've not been able to find much to this effect. I'd love to be educated on this.
- K&N 4" x 9" filter - strap it right to the TB, because I read stickies. :th_winking:
- MPS - 3.4" pulley and appropriate belt - 716? (Please help.) I'm pretty sure I can't go to 3.3 right off the bat, but if the scanner shows no knock, then... what? The PCM advances the timing by itself and I can judge whether or not to drop to 3.3? How does one know? Or do you just drop to the next pulley as soon as you have zero knock?

Anyway, that's my ZZP cart. No pulley puller yet, because I'm hoping to grab one off a forum like this. Comes to just over $700 so far. Maybe some of these parts are available used on forums and such, save me some bucks.

Now: here's where I run into the "give a mouse a cookie" bit. Everything I'm reading says I really want to intercool right off the bat, or maybe immediately after fixing the U-bend (seriously, GM). So:

I want to intercool. That means I want to machine out my lower intake manifold, and I probably also want to machine out my blower housing to match it, too. If I'm machining out my blower housing, I probably want to machine out the inlet port. If I do that, I want a throttle body to match the new inlet port - Northstar throttle body. Of course, I still need a cone filter to slap on that throttle body, and Mother of God, I'm pretty sure now they're going to hear my blower scream on Mars. Now, let's pretend I'm doing this right off the bat with no other mods. I know that stupid U-bend is there (UGH, WTF GM), so I'm going to want a down pipe. Now, this is a fine stopping point, since the power log is not as huge a fix as the down pipe, but I'd probably end up doing it anyway. All of this is probably enough to support a 3.2" or 3.1" pulley, and now I've run my injectors dry. Into the engine we go. Since we're in there, I might as well cam, and I'll do new springs and retainers, too, and a chain, because the car has close to 60k on it. Finish the job off with aluminum coolant elbows (because those damn plastic ones failed TWICE!! on my 2000 Ultra), and all of a sudden, I've sunk $5000+ into my car, and it's "Bye, kids, I'll see you next weekend, tell your mother to brush your teeth before school."

So I'm thinking my plan is this: sink the initial $700 I've laid out above, then intercool in a major $3500-ish project later on if I feel like taking that on.

Is there anything obvious I'm missing? Any alternate paths you would take?
 


160 is far too cold, stay at a 180 or stock thermostat.

To my knowledge you can still run headers in the park ave's, I'm not sure how much if any modifications would have to be done.

You might be able to run that 3.4 with a plog/downpipe, you'll just have to see what the car thinks of it. The PCM won't continue to advance the timing, its always at a set number for WOT that it tries to reach. To me anything past a 3.4ish pulley you'd need headers for the added amount of air you are wanting to flow.

I think you should choose one or the other on the I/C and cam idea. A intercooler can really help but they do have draw backs and can be a real pain in the ass sometimes with the amount of parts you need to run one.
 
rafadavidc said:
First post, but I've been reading up on this engine for years and years by virtue of having owned two L67s since 2007. Yes, I've been through all the stickies. I'm thinking of pulling the trigger when the weather warms up, and I want to have the stuff and the plan good and ready to go. I keep running into the "If you give a mouse a cookie" problem, though, which I'll outline below.

There are two major complications to this project:

- The car in question is a 2004 Buick Park Avenue Ultra. The GM C Platform is very, very similar to the H Platform (Bonneville), but I'm afraid of differences in the firewall or undercarriage (for example) that would make things like headers or downpipes incompatible. An example that comes to mind - the Bonneville uses a different length supercharger belt than the GTP, and that seems weird to me, since it's the same engine. Also: wbodystore.com --> okay.jpg

Welding would solve this.

- This is my daily driver. I would obviously do this over a weekend and probably take a few days off work as well. This complication is mitigated by a close buddy who is a certified GM mechanic. HELLS YEAH!

On to my mods list: Here's what I have in my ZZP cart so far.

- ZZP PCM - Because I'm probably not spending $500 on an HP Tuner, unless my buddy wants to do that, then I'd do like $200 of it and let him keep it. All options stock.
- 160* Thermostat - Because why not. All the reading I've done indicates the 2004s should have 180 or hotter, but I'm pretty sure that's for the GPs with the L32 motor. I have an L67 with a Gen3 blower.
This will just kill fuel economy
- TR8 Iridium spark plugs - Because I'm not changing these damn things every 6k. For the colder thermostat.
These will foul every 6K on a near stock engine. You don't put colder plugs in for a colder thermostat, if anything, you'd put in higher temp plugs. But the reality is, every 50-100 hp if increasing boost or compression to get it go one step colder. For most lightly modded 3800's, 605's will idle nicely and help keep it running a little cooler. 104's/TR6's won't idle as nicely.
- Power log and off-road down pipe - Fix the stupid U-bend (really, GM?) and front manifold; off-road because I can delete the O2 sensor code with the PCM and still pass emissions without a cat. I'd polish (and port?) the rear manifold myself. Decided on this combo over a set of Pace Setter headers for cost-effective solidness. Further, besides an incremental improvement, I can't really see what headers are doing for me over the combo of power log + polished rear manifold + down pipe. I've not been able to find much to this effect. I'd love to be educated on this.
Headers are going to flow better, let you run a smaller pulley, or use lower octane for the same pulley.
- K&N 4" x 9" filter - strap it right to the TB, because I read stickies. :th_winking:
Probably going to cause more KR in the city, bump fuel economy, unless it throws off your maf readings.
- MPS - 3.4" pulley and appropriate belt - 716? (Please help.) I'm pretty sure I can't go to 3.3 right off the bat, but if the scanner shows no knock, then... what? The PCM advances the timing by itself and I can judge whether or not to drop to 3.3? How does one know? Or do you just drop to the next pulley as soon as you have zero knock?
You're going to want to see if you can even run the stock pulley without KR first. If you have the ability to tune, you'd bump the timing up to 18-19*, if you can run that, you can try a smaller pulley at lower timing, say 15*. Repeat as necessary.

Anyway, that's my ZZP cart. No pulley puller yet, because I'm hoping to grab one off a forum like this. Comes to just over $700 so far. Maybe some of these parts are available used on forums and such, save me some bucks.

Now: here's where I run into the "give a mouse a cookie" bit. Everything I'm reading says I really want to intercool right off the bat, or maybe immediately after fixing the U-bend (seriously, GM). So:

I want to intercool. That means I want to machine out my lower intake manifold, and I probably also want to machine out my blower housing to match it, too. If I'm machining out my blower housing, I probably want to machine out the inlet port.

Unless someone has tested this, I can't see why the H bar would impact flow or outlet temperatures in the slightest. Its not sealed against the core, the air isn't going to make a 180* turn just to go to the furthest ends of the core. Natural order of things is to take the easiest, most direct route.

If I do that, I want a throttle body to match the new inlet port - Northstar throttle body.

You're nowhere near needing a larger TB.

Of course, I still need a cone filter to slap on that throttle body, and Mother of God, I'm pretty sure now they're going to hear my blower scream on Mars. Now, let's pretend I'm doing this right off the bat with no other mods. I know that stupid U-bend is there (UGH, WTF GM), so I'm going to want a down pipe. Now, this is a fine stopping point, since the power log is not as huge a fix as the down pipe, but I'd probably end up doing it anyway. All of this is probably enough to support a 3.2" or 3.1" pulley, and now I've run my injectors dry.Into the engine we go. Since we're in there, I might as well cam, and I'll do new springs and retainers, too, and a chain, because the car has close to 60k on it. Finish the job off with aluminum coolant elbows (because those damn plastic ones failed TWICE!! on my 2000 Ultra), and all of a sudden, I've sunk $5000+ into my car, and it's "Bye, kids, I'll see you next weekend, tell your mother to brush your teeth before school."

Forgot about the transmission investment to support that kind of power having to move around that much mass.

So I'm thinking my plan is this: sink the initial $700 I've laid out above, then intercool in a major $3500-ish project later on if I feel like taking that on.

Is there anything obvious I'm missing? Any alternate paths you would take?
Click to expand...


I'd suggest intercooler/downpipe or headers/modded rockers.
 
Alright, you say "intercooler." Am I hearing you correctly when I hear "intercooler kit, machined lower intake, machined blower outlet, EGR delete, PCM, supercharger belt (obviously), cone filter, and 3.3-inch pulley"? Or am I reading too much into that?

Alternately, what are modded rockers doing for me? Should I do those instead of stuff in my ZZP list, or in addition to? The ZZP list kind of intentionally avoids going into my engine for reasons that are admittedly arbitrary.
 
When I say intercooler I mean, the core, lines, pump, heat exchanger, machined lower, no ported blower, egr delete, no pcm, belt, no cone filter, and start with a 3.4 pulley.

Rockers will give you some top end. Honestly though? You could probably do without. Just make a torque machine, and enjoy the car.

Go through the red stuff in the quoted section of my last post.
 
Id do the stuff in your initial list and then plan on doing a turbo kit down the road rather than the intercooler and stuff. At this point if you're going to sink 3500-5000 into making a wbody fast just turbo it. You'll have much more room to go on. Either way you're going to have to upgrade the tranny anyway.
 


matt5112 said:
When I say intercooler I mean, the core, lines, pump, heat exchanger, machined lower, no ported blower, egr delete, no pcm, belt, no cone filter, and start with a 3.4 pulley.

Rockers will give you some top end. Honestly though? You could probably do without. Just make a torque machine, and enjoy the car.

Go through the red stuff in the quoted section of my last post.
Click to expand...

Starting with a 3.4" seems wise, of course. Why no PCM, though? EGR delete will throw a code, and I live in an emissions area. This goes double if I do the down pipe - aftermarket cats are a coin flip to throw an O2 code, from what I understand.
 
rafadavidc said:
Starting with a 3.4" seems wise, of course. Why no PCM, though? EGR delete will throw a code, and I live in an emissions area. This goes double if I do the down pipe - aftermarket cats are a coin flip to throw an O2 code, from what I understand.
Click to expand...

Sorry, wasn't thinking clearly. Either continue to use your EGR or get a PCM.

You can get quality aftermarket cats, but they're $200+ a pop.
 
88formula said:
Put a VS cam in it. You won't regret it.
Click to expand...
This sounds like a huge project. Except for the rear manifold, I'm pretty sure I can get to everything in the ZZP list with the engine sitting in the engine bay and the car sitting on the ground on jack stands. Am I wrong? I'm hoping for a driveway-type project here.
 


personally, i think you should get headers.
you will be able to run more timing, and with the 3.4 pulley you will have so much more flow up top.
the route i would take is...3.4 pulley, rockers, headers. ive seen those setups go 230-250 whp.
without headers you leave a lot of power out on the table for not too big a price.
then you can intercool down the line if you want moar powa.
 
rafadavidc said:
This sounds like a huge project. Except for the rear manifold, I'm pretty sure I can get to everything in the ZZP list with the engine sitting in the engine bay and the car sitting on the ground on jack stands. Am I wrong? I'm hoping for a driveway-type project here.
Click to expand...

You can do a cam in the driveway as long as you have two jack stands.

ctracer said:
personally, i think you should get headers.
you will be able to run more timing, and with the 3.4 pulley you will have so much more flow up top.
the route i would take is...3.4 pulley, rockers, headers. ive seen those setups go 230-250 whp.
without headers you leave a lot of power out on the table for not too big a price.
then you can intercool down the line if you want moar powa.
Click to expand...

Requires fabrication skills.

OP?
 
I live in Cali and emissions are strict here idk how strict they are we're you live but of its close to Cali. You need to have CARB approved headers and intake C.E.O numbers for them
 


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