The "Do I need a tune" question
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From: Bridgewater,Ma
The "Do I need a tune" question Here is a result I've found many time throughout the years.The biggest question is why get a tune with minimul bolt-ons? Well,sometimes tuning will give more power gains that alot of the bolt-ons you buy and for a cheaper cost.
Car in question - 125k miles,M6, 98 Z28. Has a flowmaster muffler,air lid and a Jet chip.Car ran fine.
Drove the car to get up to temp. All runs where at 190-192 engine temp at start of the runs.They were all logged for KR and A/F.
As it came in.Did 3 runs with cooldown inbetween.All runs were very close to each other with the highest at 300hp/276tq. No KR and A/F stayed around 12.7-1. I was thinking the Jet chip was doing pretty good.
Took out the chip and street tuned the car.After about 20 minutes on the street we hit the dyno again.Took 2 runs to get the WOT A/F and timing in check.
Cooled car to the proper temp and did 3 runs that way. Car made consistant power within 1% of each other.Final #'s were 316hp/300tq. This was with 4 degree's less timing than before and a slightly richer A/F around 12.5-1.
Made a great gain across the whole curve.Here's the graph.
Just figured I'd share this.It surprised me on the gain.
Car in question - 125k miles,M6, 98 Z28. Has a flowmaster muffler,air lid and a Jet chip.Car ran fine.
Drove the car to get up to temp. All runs where at 190-192 engine temp at start of the runs.They were all logged for KR and A/F.
As it came in.Did 3 runs with cooldown inbetween.All runs were very close to each other with the highest at 300hp/276tq. No KR and A/F stayed around 12.7-1. I was thinking the Jet chip was doing pretty good.
Took out the chip and street tuned the car.After about 20 minutes on the street we hit the dyno again.Took 2 runs to get the WOT A/F and timing in check.
Cooled car to the proper temp and did 3 runs that way. Car made consistant power within 1% of each other.Final #'s were 316hp/300tq. This was with 4 degree's less timing than before and a slightly richer A/F around 12.5-1.
Made a great gain across the whole curve.Here's the graph.
Just figured I'd share this.It surprised me on the gain.
Great points. A tune allows you to see how and where your car makes the best power rather than just using generic af and timing values. It also allows you to verify the car is running properly. I get lots of bolt on cars that come in for "just tunes" only to find they don't make any power and have other problems. I've had more horribly lean running bolt on cars than anything else and everytime the owner was unaware of a problem. The few hundred $$$ for a tune is nice if you gain some power and get a good dyno sheet, but it's even better if it ends up saving your motor.
not only power, but you can adjust things like rev limiters, fan temps, torque management...
i couldn't beleive the difference in feel after torque management was disabled!! drove cam only for 4yrs with TM fully enabled...first drive after was AMAZING
i couldn't beleive the difference in feel after torque management was disabled!! drove cam only for 4yrs with TM fully enabled...first drive after was AMAZING
Nice gains. Jet stuff is garbage anyway, but someone can absolutely gain power with a tune on a BONE STOCK car.
I've tuned a couple of stock automatics at the track, and just with minor timing, A/F, shift points and TQ management adjustments dropped 3-4 tenths.
I've tuned a couple of stock automatics at the track, and just with minor timing, A/F, shift points and TQ management adjustments dropped 3-4 tenths.
Thread Starter
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iTrader: (12)
Joined: Nov 2001
Posts: 14,865
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From: Bridgewater,Ma
I tell people the best thing to do is to have the car dyno'd while being logged atleast once every year or 2. This can bring out problems you never felt. Alot of bad Mass air meter's this year.Most people didn't even feel the loss of 20-60hp.
I tell people that I can get their mail order cals closer for the GenIII platform in SPEED DENSITY and they think I'm crazy! Aging MAFs are a huge headache. They all report low (lean) and they never set any type of that code to draw attention to themselves. There were a lot of them last year, and there are more this year.
