disappointing dyno result

[dat240z71]

I went to the dyno yesterday and I'm a bit disappointed in the result. my first run was at the stock setting psi and got 190 wrhp, AF was very good so i took it up to 10pis and got 198wrhp and AF mixture still but when i tried to go 12 psi it started to ping and the guy had to back off, then i was like try 15 psi,( 15psi is where i would like to run) so he get on it and if start to ping so he get off again this time we make 215 wrhp but only got the RPM up to 5500. I had them stop and left on the way I had the boost set at 12psi I tried to run at 12 psi and it ping so I pulled over to check things out and found that the distributor was advanced as fas is it could go so I turned it back half between full retard and adv. got back in the car and now I can boost 12psi all day. I want to go back to the dyno and see if this makes a difference but before I go I would like to know what you guys think could this have been my problem, the guy at the dyno shop told me I need more fuel as I ran lean on the last two runs, I just wonder if my lean condition was caused my timing being so far advanced.

MY set up

71 240z

83 turbo set stock management system

89 supra intercooler

turbo x blowoff valve

manual boost controller

LSD

3" EXT. part press bend and part mandrel

3" muffler

custom 2 "1/2 down pipe from Scottie g

cold air intake

plug stock pop valve opening

93 octane gas

[Zvoiture]

Is this an L28?

steve

[dat240z71]

yes it's a l28et

[Mr Camouflage]

Are you running the stock FI computer?

If so get a tunable aftermarket computer.

[echocluster]

did you do any better? i am about to do the same to my 71. what kind of numbers were you hoping for? are you going to get an after market management system. how much would that go for?

[yellowoctupus]

Is it possible you knocked some carbon out of your cylinder dropping your compression ratio down? Just thinking if you've never had the engine apart, I know running on differnet fuels can do that sometimes too. (alcohol etc).

[jmortensen]

Is it possible you knocked some carbon out of your cylinder dropping your compression ratio down? Just thinking if you've never had the engine apart, I know running on differnet fuels can do that sometimes too. (alcohol etc).

I wonder if maybe he figured out his problem in the last 4 years since this post was originally made...