compression and nitrous


New Member
Feb 21, 2010
Hammond, La
i have a 97 gt with complete pi swap block heads. the heads are milled 30 stage 2 modular powerhouse cams still manifold accufab plenum and tbody. im wondering if its safe to spray with the compression being around 11-11.5? im new to the modular motors i can build a ls1 in my sleep though so any info would be helpfull
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that was a stock bottom end car? i dont wanna blow it to pieces just over wanting to spray it. i have 24lb injectors and holley 255 pump im only wanting to spray like a 50 or 75 just if someone gets real cocky.
yea im good man i dnt wanna blow my **** up im use to lsx motors it dnt take ne where near that to make that kinda power from a lsx ill just stay with what i have n finish my bolt ons n get it dyno tuned. im about to start building a ls1 powered miata soon the mustang was just something new for me to learn
I've always wondered if you can shave the heads on a 2v. Did you have any problems getting the intake to fit correctly? Seems like that would change the geometry?

Anyway, nitrous works very well with high compression ratios. The nitrogen in nitrous helps control the combustion process, but you'll still need to worry about having sufficient octane. Race gas would be ideal. Otherwise, you'll need to retard the timing a bit to be safe.
Cam timing can be corrected with adjustable cam gears. I just thought milling too much would effect the way the intake fits. Same reason why a 5.4 intake won't fit a 4.6 and vise versa.

Also, .5* of cam timing for every .008" seems excessive. I milled my 2.3 .115" and it calculates to 2.5* of cam advance. :shrug:
all the work was done when i got it and no one seems to know if i can spray or how much i can spray so illl just leave it like it is and build another ls1 i know what they can handle

Stock 4.6 bottom end can handle about 425-450 rwhp and rwtq if you can manage to stay out of the knock. To get up to 425-450 rwhp with nitrous while staying at or below 425-450 rwtq, you just need to make sure you use an rpm window switch set at around 3500 rpm or so. Also, use a WOT switch or you may blow your intake.