Dynamometer Results & Comparisons - Painfully low numbers......come take a look

I recently had my car dyno'd and the results have left me depressed! Dyno graphs show 232 rwhp//261 rwtq with the AFR down in the 10's :cry: Car is a stock 99 a4 z28 and this was done on a superflow dyno. You can see the car is running to rich, but even if that was corrected it doesn't look like it would put me where a stock a4 should be. Can anyone here give me an idea of what steps I should take to see if anythings wrong with the car. If anyone here lives in my area I'd appreciate a reference to a good ls1 mechanic.

Thanks in advance


http://img.photobucket.com/albums/v430/nrk_rider/rpmdynoresize.jpg

http://img.photobucket.com/albums/v430/nrk_rider/mphdynosheet.jpg

Ouch! Those are stock 4.6l GT numbers. If you're running on all 8 cylinders and have all your spark plug wires connected, sounds like you need a compression check.

you definetly need a compression test , there is something wrong in there.

Looks like it is not firing on all 8 cylinder's. It can give you a flat curve like that too.Do a good tuneup with plugs/wires and clean the mass air meter.Then give it another try.

wrap it around a pole

yeah change the spark plugs and wires , get it tuned and see the cats may be clogged (might need to remove them) tune the afr to 13 ,if not then there is something wrong.

i have tuned a m6 vette 2002 that made 260 hp , the guy alomst cried , told him to remove the cats , and change spark plugs with wires (cuz there were many misfires) tuned it removed the mesh and he got 347hp with nothing being changed.

If the car feels like it has the power it should for a 99 Z28 on the street, maybe you didn't dyno in 3rd gear or there was a problem with the dyno.

how about some more info? miles? mods? etc?

wrap it around a pole

Real cute asshole, hes looking for advice. Not a kick in the teeth. Take that garbage elsewhere :wrongforu

I agree with the above.

My vette dyno'd 598 rwhp and the #2 park plug wire was changed instant 657rwhp.

If the car feels like it has the power it should for a 99 Z28 on the street, maybe you didn't dyno in 3rd gear or there was a problem with the dyno.

Well the problem with that is, before I bought this car I drove a 4cyl family sedan for 2 years. So it feels fast to me because Im used to half the displacement :jest: I believe the pulls were made in 3rd gear, if you look at my dyno sheet with the mph on it, the graph runs from 70ish to 140ish which should cover 3rd gear. As far as I could tell the dyno was setup right, from what I've read the superflow dyno that shop was using is supposed to be really nice and carries a hefty price tag. But the shops website is http://www.sracing.com you can see pics of their dyno there, and I have a vid of my car on it as well if you'd like to see.

how about some more info? miles? mods? etc?

The car is totally stock. It just turned 115k on the clock, I bought it at 108k. I had the transmission rebuilt at 111k along with a new MAF and a new air filter. I baby the car a lot and it only sees about 500 miles a month if that. But after rebuilding the tranny and now this problem, I get the feeling the cars previous owners weren't nearly as kind :eyes:

Thanks to everyone who has given some positive input (you know who you are). I'll respond with any other info you want about the car. I'll be getting the car checked out real soon, but until then Im stuck driving an LS1/2 :(

I just had mine dynoed and the guy at the shop recomended 3rd gear pulls, this produced dismall #'s as well. I asked to make some pulls in 2nd and this produced much better #'s,(3rd-311,2nd-328) I know this may not get you where you want to be but it's worth a try next time you dyno.

New plugs, wires, fuel filter, and replace both front 02 sensors. Then dyno again!

Do the basics then...plugs (NGK TR5 or TR55IX if it was mine), wires, and fuel filter. Run a bottle of RedLine fuel injection cleaner through. See if A/F comes up to 12-13:1.. I think you are 40-50hp low. I would also suspect valvetrain if it doesnt pick up. Maybe a broken rocker or bent pushrod. Valvecovers are easy to pull and inspect.

Dyno should be SAE corrected in 3rd gear.

1/4 mile et/mph will show you true hp numbers, make sure to note temp, absolute pressure, track elevation, and humidty at time of run (should be on slip) so you know what density altitude is. You'll get much different 1/4 numbers running on a cold day at sea level versus a hot day at 5,800 feet. :)

yeah, get some track times and mph, that will tell the tale. everyone totally evaluating a car because of its dyno numbers is getting out of control. timeslips are my dyno pulls.

yeah but wil not tell you if you r runing rich oe lean and other info .

Looks like it is not firing on all 8 cylinder's. It can give you a flat curve like that too.Do a good tuneup with plugs/wires and clean the mass air meter.Then give it another try.Yeah, since the factory propaganda says the plugs are good for 100k, it's possible that the plugs have never been changed, which would be 3/4 of your power loss right there.

Do you have floor mats? Might have gotten under the pedal and not allowing 100% throttle.

Real cute asshole, hes looking for advice. Not a kick in the teeth. Take that garbage elsewhere :wrongforu


ok "lilbuddy1957"....go get some twat or something so you can release your stress. Some peeps take jokes too seriously.

If you have not done a full tune up yet you should do one, especially if you dont know what the last owner did to the car. If you have the $$ get plugs, wires, fuel filter, bottle of injector cleaner, dump a bottle of seafoam in the manifold to clean it up, and clean the MAF. Like alrady said, your pushrods could be bent or have some other valvetrain issues. Do a compression check also. Low compression can give you a loss of power. I would give it a tune up, re-dyno, and then take it from there.

Well guys, I had the car looked at this week. They found a vacuum leak, he showed me the hose they pulled off and it was all but split. They also performed some type of relearning procedure on the crankshaft and said it looked like someone had messed with the pcm before. Just driving it home the car did feel a bit stronger but I got some other things that need fixing.

I also need to go ahead and change out the plugs and wires, This guy recommended bosch platinum plus 4's, any comments or suggestions regarding these plugs or other ones? I hear a lot of people on here go with NGK's.

He also wants to hook my car up to some machine he has that cleans out all the carbon build up.

Thanks.

hey post your stock results after all that tune up...please

I wouldn't waste the money on the +4s. IMO the NGKs are a great plug for less cash. Make sure the gaps are set correctly and check the o2 sensors as well. Good luck!

If I read that right in one of your posts, it might be a good thing to put your stock MAF back on. A lot of guys have a lot of problems when they go with an aftermarket MAF on a nearly stock engine. The stock one is capable of handling up to 550rwhp. I'm positive that's where some of your numbers are being left at.

I also need to go ahead and change out the plugs and wires, This guy recommended bosch platinum plus 4's, any comments or suggestions regarding these plugs or other ones? I hear a lot of people on here go with NGK's.


Any mechanic that tells you to run Bosch platinum +4's you need to stay away from. I can't even count the number of times I've had customers come in complaining of their car running like crap just to find out they had those junk plugs in. Stick with the NGK 55 like previously suggested.

can o' gas and a hand full of matches j/k good tune up first

Any mechanic that tells you to run Bosch platinum +4's you need to stay away from. I can't even count the number of times I've had customers come in complaining of their car running like crap just to find out they had those junk plugs in. Stick with the NGK 55 like previously suggested.


word...those bosch plugs are the worst ever. They usually make cars run worse than what they did with their old plugs.

i like the ngk tr-55 plugs have had good luck with them.