Dyno numbers are in.. Technical help needed!!

[UnderPressureGT]

Today i just got back from the dyno and put out 513 hp and 482tq... If you look at the picture, the air fuel is damn near perfect the whole rpm range..it doesnt lean out at all.. after that was done, he gave the car back and said it was ready to go...

On the way home, driving in 4th gear, at 4900 rpm, i can swear i hear a ping (marbles in a tin can).. Why is this??? i feel unsafe driving the car hard if its gonna ping.... is there too much timing over 4000 rpm??? The tune was done using an SCT custom chip.. From what i know, he had the chip pull more timing out as the ACT temperature increases soo i wouldnt have to worry about too hott of an air charge.. What i dont get is, how come i didnt hear a ping on the dyno, yet on the way home, it was clear as day???

here is the graph..

 

[txstang84]

that's a good one, nice numbers by the way...you're positive it was detonation?

 

[UnderPressureGT]

thats the only sound i can associate marbles with..... the engine runs strong under part and full throttle, just that sound at 4900 rpms, i want to say it is detonation.. I blew my headgasket last week and he told me by the looks of the gasket, it ran lean/detonated.....

When my carw as put ont he dyno today, the tps was very erratic and he said that the tps is why i probably blew the headgasket.. "the tps was not working therefore when the car was WOT, it wasnt getting enough fuel"..... After he put a new tps on, it ran muchhh better and fuel was not an issue..... only, it pings!!

 

[txstang84]

does it ping at any given throttle setting? or just at wot? you might still be battling some fuel issues..

 

[txstang84]

the tps theory is a sound one, based on what I do know about the eec system, I know my friends '88 ran a little funky in the midrange when his went bad...but his was only bad between like 20-60% throttle...

the only other thing i can think of was maybe the tuning needs to be gone over again, i guess call the guy up at your earliest oppurtunity and let him know what's going on...

 

[UnderPressureGT]

ping is at WOT only..

 

[Polter83]

Might try putting the timing one less degree.

 

[VibrantRedGT]

This is where a BTM works great. At this point if you don't have one I would suggest you purchase one. Could knock off a few degrees from turning a dial inside the car. Worked wonders for me when my cars was blown.

 

[Nutzy19]

isnt that close to " block splitting" numbers? I remember you were gonna go with a more conservative tune of like 460-475....

 

[UnderPressureGT]

isnt that close to " block splitting" numbers? I remember you were gonna go with a more conservative tune of like 460-475....

its not running 513 all the time... by the time the temp reaches 195 on a hotttt day, im seeing around 466 hp to the wheels....

 

[9 Deuce GT]

Any bets on how long this set up lasts?

Anyone?

 

[StreetStang302]

Any bets on how long this set up lasts?

Anyone?

I'd say it lasts a good-long time, maybe 3-5 years, or until he gets a 331 that he talks about sometimes. He knows what he is doing and the drivetrain is extremely healthy.

 

[Dean85GT]

Dude, dont beat on the car and hit WOT anymore until you figure that out. Although that is not technical help but really figure out the problem before running it hard especially if it is detonating cause you dont want to gernade it again.

 

[UnderPressureGT]

Any bets on how long this set up lasts?

Anyone?

In which sense does what you said have any bit of contribution to my thread whatsoever???? Keep the junk out....



Dean... I called JD's today and he said that hes gonna pull more timing out uptop and drive it hard on the road before i take it back home on monday.... looking at the graph, would you say that its too much timing??

 

[Dark Knight]

not up on FI cars, but do you have a fuel pressure guage where you can see it? if the voltage to the fuel pump drops, will the pressure and volumn drop too? not enough voltage to the fuel pump when you have other things running, like a radio etc? maybe getting to the max the stock fuel line can support too?

 

[UnderPressureGT]

by the graph, the air fuel in the range of pinging is 11.5 which should really not make it ping right???.. to answer your question, no i do not.. my fuel pressure is on the ahraeder valve..... i do have a 150 amp alternator tho and my charge is does not drop below 13 volts though

 

[Dean85GT]

Well, be sure to tell us what happens.. Im curious as to what the problem is now.

 

[92GreenGT]

Joe, time for that methanol kit we had talked about.

 

[txstang84]

Joe, time for that methanol kit we had talked about.

reduced chance of detonation and 70-100hp, all for $400-sounds like a great deal to me

 

[9 Deuce GT]

All bs from my previous post aside, I think I would really have to take a look at the shop you are using's ability to tune a car. Considering that you already had problems, why wouldn't they run the car on the street themselves before they gave it back to you? That is bad customer service if you ask me. Must be they like to waste many hours of labor, and not get payed for it.