Posts like a Corvette
Join Date: Jan 2007
Location: San Diego, CA
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Please comment on "daily driver" proposed mod plan
Well, I've got the mod bug on the “daily driver” ('98 LeSabre, L36, in sig). Thanks in large part to what I've learned from this forum, I've got something of an upgrade plan coming together. Please comment, critique, and make suggestions on my proposed performance modifications:
-Nothing big; just a little more “pep” in the daily driver; particularly at mid to high rpm’* (e.g., passing on the freeway).
-Little to no loss at low end rpm’*.
-Maintain at least 20 mpg in mixed city/highway, and 30 mpg highway.
-Maintain good reliability.
-Be able to pass California emissions and smog visual inspections (among other things, necessitates keeping as “stock-looking” as possible).
-Mods must be “reversible”, and “portable” to the 2004 LeSabre (for if and when I get rid of the ’98 and “inherit” the ‘04 from the wife 5 or so years down the road).
-Must be within reach of a "shadetree mechanic" with hand tools.
What I DON’T Want:
-A race car / drag racer.
-Lopey idle, “bang/screech” shifting, a “tire-burner,” or any of that nonsense.
-Something that needs frequent retuning.
-Counting only car parts (i.e., NOT counting tools, diagnostic devices, programmers, etc.), not more than $20 per hp gained.
1. 180° drilled thermostat / Prestone (already done). Expectations: improved UIM life (though minimal performance gains expected; more a "support mod"). Cost: $35
2. 4T65E shift kit (already done). Expectations: crisper, more precise shifting, though no measureable hp gains expected (again, more a "support mod"). Cost: $90
3. Ported LIM (in process). Expectations: higher VE% (from ~70% to ~73-75%, increased torque peak (from ~4000rpm to ~4200 rpm), maybe 5 peak hp. Cost: $40 (already have junkyard part)
4. Modified UIM runners (in planning stages; a “poor-man’*” HV insert). Expectations: higher VE% (from ~73-75% to ~75-77%), increased torque peak (from ~4200 rpm to ~4300 rpm), maybe 5 peak hp. Cost: $40 (already have junkyard part)
5. PCM tune (planning to obtain DHP PowrTuner). Expectations: raise shift points (to ~5800 rpm) and optimize fueling to further increase VE% (to ~80%), etc.; maybe unlock another 10 hp
6. 1.8 Rockers (still determining options and comparing vs. cam options) Expectations: increased VE% (perhaps beyond 80%), increased torque peak (from ~4300 rpm to 4500+ rpm) more high-end torque, maybe another 10-15 hp. Approximate cost: $350 to $600 (depending on need for springs, rods, retainers, valve seals, etc.)
7. Gutted airbox /smooth bellows / K&N Only if needed as support mod. Cost: $55 (already have this, but not needed at current mod level)
8. Throttle Body port or swap Only if needed as support mod (very doubtful, IMO). Approx cost: $150 to $200
9. Power log or port front exhaust Only if needed as support mod (also very doubtful, IMO). Approx cost: $100 to $150
10. PCM re-tune Expectations: raise shift points (to ~5900-6000 rpm) and further optimize fueling, etc.; maybe unlock another 5-10 hp
In the end, I would expect to raise torque peak from about 4000 rpm (stock) to about 4500 rpm, increase total hp (over stock) by about 35-40, and spend about $700 to $800 on parts.
So, what do you think?
Are my expectations reasonable?
Anything else I should consider?
Are any of these mods going to put reliability at great risk?
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