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Discussion Starter · #21 ·
As someone who started with a 3.4" pulley, 1.0 tune, and basic intake/exhaust items for ~$500, I was running ~13.9 in my GTP consistently enough to win a street bracket class at my local track before. It's all in how people maintain their vehicles and listen to what it needs to run cleanly.

After that, I had a cam-only, non-intercooled, stock heads setup running 12.7's at over 110 on street tires and a slipping $75 junkyard transmission. That's something most people wind up trying to accomplish with all 3 of those upgrades filled-in and more. The range of possibilities is down to how much time/effort & smart application of money you apply.

Throwing a pulley on and not cleaning your MAF or other maintenance can have junk results or make it run like a rocket, but taking care of all your components & systems will put you more to the rocket end of the spectrum more consistently... Especially when you're a poor college kid maximizing the free/custom mods, as well. ;)
 

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Discussion Starter · #22 ·
I can relate to that train of thought.....doing more with less, putting in the time and effort and above all, as you said, the smart application of money you apply. The world of computer controlled AF delivery and ignition timing is a bit more hi tech than the old days of carbs and and HEI ignition but the concept of matching the right components, attention to detail and tuning dont seem too far apart. A cam only, non intercooled, stock head set up with a junkyard trans running 12.70s and trapping at 110 kind of proves that point. By the reasoning of a lot of posts I see, to run 12.70s, you should have had trick high dollar heads, an intercooler or you'd "melt your pistons". And how could you do all that without a custom trans with a 3.69 final drive? Like your 12.70s 3.4 pullied project with the basic tune and just a cam, I can relate to that attention to detail/ smart application of money by getting a 350 olds into the mid 12s in a G body with no trick roller cam, just a hydraulic flat tappet cam, stock style stamped steel rockers, mechanical fuel pump and a 18" mechanical flex fan. The power came from matching the right carb/cam/intake combo and taking the time to port match the intake, port the iron heads,dial in the carb and ignition timing. The right stall converter, gear, and above all, puttting the power to the pavement. A line lock ,slicks, boxing the lower control arms with plate steel and air bags in the coils do a great job of planting that right side of the axle on the ground. Low 1.70s 60 foot times/ 12.50s and really no trick,high dollar stuff. So many times I've heard one of 3 comments . "Is it a 455, a 350 chevy or does it have nitrous"?

You and Mr N20 seem to have that same approach to making a L67 fast without throwing a ton of cash at a project. I'm tending to ignore the posts lately that claim you need headers/ a custom tune/ 1.9 rockers with a 3.4" pulley/ 13s in the quarter, or "you'll melt your pistons". Seems like the first and most important thing in messing with this engine is continuously watch the KR anytime you alter something or just keep an eye on it period. With spending under $1000 on this 05 Impala SS, 3.5 pulley/ 3" DP/ front PLOG and the other basic stuff and seeing how quick it runs with very minimal KR, it seems like Im on the right path by listening to the right people you do more with less.
 

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Ya, just pay attention to your own vehicle's feedback, and it will report back how it likes the changes. There's minor differences in results across the market, but the general idea is to have the powertrain "last being fast", whatever that means to you.
 

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1998 GTP coupe. All stock and rust free. That will change soon.
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One of the best arguments for even a base tune isn't just KR, There's an issue in the stock tune that cuts off fuel as a method of rev limiting for power reduction / torque management. What ends up happening is a modded engine that hasn't had the torque management modified will be making a lot of power at the top end, and all of a sudden the fuel gets cut off and one or more cylinders (usually #3 or #4 because of the layout of the airflow) goes lean. This makes the top of the piston hot, the top ring expands, and without a good ring gap it pops a chip out of the piston.

I think if you're happy with your current setup, then keep an eye on it, don't beat it into the ground. If I get my hands on a 05+ PCM harness I could make an offboard tuner and help you out.
 

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Discussion Starter · #25 ·
One of the best arguments for even a base tune isn't just KR, There's an issue in the stock tune that cuts off fuel as a method of rev limiting for power reduction / torque management. What ends up happening is a modded engine that hasn't had the torque management modified will be making a lot of power at the top end, and all of a sudden the fuel gets cut off and one or more cylinders (usually #3 or #4 because of the layout of the airflow) goes lean. This makes the top of the piston hot, the top ring expands, and without a good ring gap it pops a chip out of the piston.

I think if you're happy with your current setup, then keep an eye on it, don't beat it into the ground. If I get my hands on a 05+ PCM harness I could make an offboard tuner and help you out.
 

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Discussion Starter · #26 ·
OK, that's good to know. I'll take all the info I can get. Now that's the car is somewhat set up the way I want it, I pretty much drive mellow around town. An occasional 0-60 , shift points set at 5800. 6000 seemed like too much on a stock valvetrain. I'm not much for pushing it to fast on the highway. Those days of winding a car out to 120 are in the distant past. Punching it at 70-75 and maybe up to 93 (shift set at 5700) where it shifts into 2nd is about the extent of my highway messing around. The car is stable, no vibrations or anything like that, I just get really nervous of the cops busting me and there goes my low insurance rates/ clean driving record.

I don't see any dragstrip visits since our local track is closed down. It sounds like it would be in my best interest to eventually get that PCM tuned to keep that vintage mill intact for many more miles. Has 127,000 on it now. Top end lean out due to that stock torque management set up doesn't sound like something I want to keep that way long term. Thanks again for the info/word of caution.
 

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Just another tune set up.....like most have already done. For me(probably because several moons ago I fried my 3800 SC in a BIG WAY and lots of DOLLARS.) So, after that occurance, and rebuilding my 3800 with a lot of new/good parts(DIAMOND PISTONS AND FRESHENED UP BLOCK and while I was at it I had DYNO BRIAN tune my PCM(MOST EXCELLENT IN EVERY WAY). I also had to replace the old cracked heads. This no BS, if you have a tuning issue......talk to Dyno Brian. Your issues will most likely go away and your car will perform MOST EXCELLENT. When I drive my hot rod now days, it will do everything I want and more. AND, at highway speeds, it still gets close to 18/20 MPG at cruise speeds (60/70 mph). The car is totally everything I could have imagined after the BRIAN TUNE. I use BP 91 oct with good results. HOWEVER, have you guys and gals seen the latest PRICE INCREASES with GAS? !!!! Good part is I do have an ACCORD that gets great mileage. The gtp.....well, it's ok but not excellent. I do run my ride a bit on the rich side... (had a bad experience frying pistons).
Getting back to tuning, DYNO TUNE MOTOR SPORTS and let them set you up with a most excellent PCM TUNE. They will need some specific info for a good end result. Hope everyone has the best of luck with their rides. And as always, reach out for helpful info in this forum. Jake, mr. goodwrench One last tidbit of info, I run my GTP colder than most, no thermostat but do allow WARM UP TIME BEFORE DRIVING HARD. Just enough to get a little heat on my toes! And heat up the engine as well as the OIL in crankcase. And of coarse, I run MOBILE ONE oil...... Thanks for reading my post, Jake/Mr goodwrench. PS, I am a competiton USPSA shooter and all my firearms use MOBILE !.....OF COARSE!
 

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Ha! FYI, if you get your 3800 car down to/below 20mpg cruising without towing a 2,000lb trailer, you're really doing it wrong. I know Bryan has had good results, but I doubt he's sending cars out the door pissing extra fuel out the exhaust just because the owner is scared after screwing up a previous engine.

It's not like turning a lawnmower carb screw that applies a blanket change across the board, or there'd be no point to the benefits of EFI. Heck, I think I averaged 19mpg in the mountains last week on my Blue Ridge video cruising with the nitrous Z06 Vette and Procharged Camaro. Every 400+hp 3800 I've been around still gets 25+mpg in regular cruise scenarios (maybe ~2 less on 3.69 gears, but those become nearly useless by the time you get to a level that might be fun to try them... been in 2 cars in MN that had them, and it wasn't worth it).
 
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