Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Thread Starter
Registered User
Joined: Jan 2002
Posts: 50
From: Atlantic City, NJ
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by mebanditws6
Yes, change your spark plugs and get some NKG's like mine, preferibably the Iridium version instead of the Delcos. Also, get a can of GM Top Engine Cleaner from the dealership and run that through. If you're familiar with Seafoam, this is basically the same except it comes in a spray can. After driving the car warmed up, disconnect both AIR hoses (right by the coil packs) and spray a can of this stuff into the throttle body while the engine is running. Let the car sit for at least 30minutes and start back up. Your car will blow out huge amounts of smoke from burning off the cleaner and carbon. What this does is clean out your combustion chamber and prevents any hot spots that could cause pre-ignition. With this and a plug change, you should dyno in the 290's. 
Jason
Jason
Last edited by damon_Z; Nov 28, 2004 at 07:43 AM.
Registered User
Joined: Nov 2001
Posts: 1,151
From: orlando,florida,usa
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
i have to formulas
the 99 formy went 13.56 @ 103.27
the 00 formy went 13.60 @ 101.66
both 3.23 autos. go figure. just enjoy the car.
the 99 formy went 13.56 @ 103.27
the 00 formy went 13.60 @ 101.66
both 3.23 autos. go figure. just enjoy the car.
Registered User
Joined: Aug 2003
Posts: 659
From: Orlando, Florida
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
I would change those spark plugs for sure...this is what all 8 of my plugs looked like at 47,000 miles...Factory Delco plugs.
http://www.mustangmods.com/data/5431/dsc01770.jpg
http://www.mustangmods.com/data/5431/dsc01770.jpg
Registered User
Joined: Jan 2002
Posts: 5,308
From: Oshawa - Home of the 5th-gen
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by DanBUCF
this is what all 8 of my plugs looked like at 47,000 miles...Factory Delco plugs.
http://www.mustangmods.com/data/5431/dsc01770.jpg
http://www.mustangmods.com/data/5431/dsc01770.jpg
They've got that nice "tan" color to them
(and there's no carbon build-up or anything
).
Registered User
Joined: May 2002
Posts: 622
From: Nashville, TN
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by damon_Z
Doing a plug change and using an engine cleaner aren't mods, right?
Jason
Thread Starter
Registered User
Joined: Jan 2002
Posts: 50
From: Atlantic City, NJ
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
I just made an appointment with TT Performance for this Saturday to dyno the car with air/fuel ratio, KR, and timing monitoring after they do a plug and wire installation. This will be my third set of baseline dynos, but this one will tell me if there really is something wrong with my car or not. I'm hoping there is something wrong with my car so that I can find out how to fix it and hopefully free up at least 25 rwhp that seems to be missing right now.
Registered User
Joined: Aug 2002
Posts: 420
From: Pasadena,CA,USA
Re: Update
Originally Posted by damon_Z
Max Power = 285.1
Max Torque = 302.0
Air Fuel Ratio was 11.9.
The car seems to have gained 4 hp and 5 ft-lb. of torque just through mileage alone. Ray, at Performance Specialties, mentioned that the car was running fat and could gain 15 horsepower through dyno-tuning. Could my air fuel ratio be the reason why my car is dynoing lower than other stock f-bodies? Also, regarding my times in my original post, I forgot to mention that 5 of the 6 passes were done when the transmission was engaged in overdrive. Does that make a difference? Thanks in advance for the info.
My baseline numbers at 6389mi are in the sig. The car has the optional SLP CME catback which might be worth 5rwhp. I think your car should be right at the 300rwhp/315rwtq mark.
Registered User
Joined: May 2001
Posts: 207
From: USA
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by Capn Pete
Mine only dyno'd 288 HP / 307 TQ a couple months ago with the setup in my sig. Your #'s may be on the lower side (the MPH reflects the RWHP)
Registered User
Joined: Jan 2002
Posts: 5,308
From: Oshawa - Home of the 5th-gen
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by FLeXNuTZ
If 280 rwhp=101 mph in the 1/4 then the LT1 shouldn't be far behind. What, maybe 270-275 rwhp? Just bringing this up because I've personally witnessed a lot of people swear up and down that the LS1 is 50 rwhp stronger than the LT1
I think that a "rule-of-thumb" is that every MPH is *roughly* ~10 HP, so if an LT1 does ~100 MPH, and an LS1 does ~105 MPH, then that's around ~50 HP difference, right?
.....not saying it's all an exact science, but these are just some commonly agreed upon facts/myths that I've come to know
.
Moderator
Joined: Jul 1998
Posts: 6,247
From: Charlotte,MI USA
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by DanBUCF
It doesn't look so bad to me...you just didn't get a freak of a car I guess. Nothing to worry about. Its still pretty damn fast. Get those 60' times down to soemthing respectable and you'll be gonig low 13's...which is right on par for a completely stock car. Who care's what the dyno says anyhow? How quick the car goes is really what is important, right? 
But for every freak there's a counter part.
Back when the LS1 f-bodies first came out there was a group of 6 or 7 of us that all had M6 cars. We'd all go to the track together and everyone would run low to mid 13s at 106-107 except for one TA it would run high 13s at 102-103 and it didn't matter who was driving it either. As we all modded our cars this one stayed slower mod for mod. To this day we have never figured out why.
Moderator
Joined: Jul 1998
Posts: 6,247
From: Charlotte,MI USA
Re: Update
Originally Posted by damon_Z
I've been thinking about getting the plugs changed, but would you still recommend that after you read the following update?
Max Power = 285.1
Max Torque = 302.0
Air Fuel Ratio was 11.9.
The car seems to have gained 4 hp and 5 ft-lb. of torque just through mileage alone. Ray, at Performance Specialties, mentioned that the car was running fat and could gain 15 horsepower through dyno-tuning. Could my air fuel ratio be the reason why my car is dynoing lower than other stock f-bodies? Also, regarding my times in my original post, I forgot to mention that 5 of the 6 passes were done when the transmission was engaged in overdrive. Does that make a difference? Thanks in advance for the info.
Max Power = 285.1
Max Torque = 302.0
Air Fuel Ratio was 11.9.
The car seems to have gained 4 hp and 5 ft-lb. of torque just through mileage alone. Ray, at Performance Specialties, mentioned that the car was running fat and could gain 15 horsepower through dyno-tuning. Could my air fuel ratio be the reason why my car is dynoing lower than other stock f-bodies? Also, regarding my times in my original post, I forgot to mention that 5 of the 6 passes were done when the transmission was engaged in overdrive. Does that make a difference? Thanks in advance for the info.
D or OD makes no difference in 1/4 mile times.
Moderator
Joined: Jul 1998
Posts: 6,247
From: Charlotte,MI USA
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by mrr23
i have to formulas
the 99 formy went 13.56 @ 103.27
the 00 formy went 13.60 @ 101.66
both 3.23 autos. go figure. just enjoy the car.
the 99 formy went 13.56 @ 103.27
the 00 formy went 13.60 @ 101.66
both 3.23 autos. go figure. just enjoy the car.
Registered User
Joined: May 2002
Posts: 622
From: Nashville, TN
Re: Why does my bone-stock '02 automatic Z28 dyno only 280.9 rwhp @ 295.7 ft-lb.?!
Originally Posted by damon_Z
I just made an appointment with TT Performance for this Saturday to dyno the car with air/fuel ratio, KR, and timing monitoring after they do a plug and wire installation. This will be my third set of baseline dynos, but this one will tell me if there really is something wrong with my car or not. I'm hoping there is something wrong with my car so that I can find out how to fix it and hopefully free up at least 25 rwhp that seems to be missing right now.
Jason