Should I upgrade my injectors?

[evil666]

I am asking this question for my brother, should he upgrade his injectors for his set up? He runs the car on 94 octane fuel and 100% methanol with the smc alky progessif kit. He monitors the car with the otc 4000e, and his 02 # seem fine ( .85 to .87 o2 ) which is on the safe side but he still gets knr from 9 to 29 knr, but not all the time.

This is his set up:My brother’s 87 Grand National t-top (92 000 km)
Stock block with trw pistons and 30 over, stock heads, 210-205 lunati cam, PT61 Turbo, 65 mm kenne bell TB and plenum, 9 inch 3000-3200 stall art carr convertor, 22 ½ boost, 94 octane with 100% methanol with smc alk injection, thdp, hooker 2 ½ exhaust, 42 ½ lbs injectors, Armstrong 100 chip, ESP front mount IC, 26 BY 10 M/T ET STREEET TIRES, 3800 LBS race weight.
BEST ET= 1.60 60FT- 7.47 1/8- 11.80 ET-113 MPH
BEST MPH= 1.72 60FT – 11.87 ET AT 114,74 MPH

According to his set up should he up grade his 009? If he should what injectors would run the best for him? Will the bigger injectors help him get rid of his KR, or is the problem something else?

Thanks hope you guys can help.
Marco

 

[suicide six]

Id say the injectors are still ok for your setup,does upping fp help with the knock?Knock is cummulative and you may be getting it earlier in the run.Could be during shifting,loose tq converter bolts,sorry plug,etc..Is car throwing any codes?Might be the chip design.Try turning boost down until no knock.A chip designed for his setup,alky included might put an end to this.Good luck

 

[2QUIK6]

Yep, its should be ok with the 009s and alky if tuned correctly. That would be too small of an injector for the PT61 turbo if he did not have alky. Put in some C116 race fuel along with the same alky setting and see if the knock goes away any..if it does that would be a sign that the tune is off possibly. Personally I would use bigger injectors to be safe but I know 009's with alky should be fine up to around 25# of boost provided that the injectors are on for 90-100% DC.

As an example, I have 60# injectors, and on a WOT 25# of boost pass my injectors run at about 60-66% DC with Methanol injection. So 66% of 60 lb is 39.6. So therefore, injectors rated at 39.6 lbs running at 100% DC could support my current tune.