OneBadRx7

Well guys its not like I am a newbie here. I am not looking for help, merely suggestions on the question I have. I was thinking of turning up the boost to 15psi this weekend for some racing, I usually run around 13 just so you know. My mods are in my sig and I was looking to see what you guys thought on running 15psi for a few 1/4mile runs. Think I will be ok or shouldnt I test fate? My motor has about 11-12K on it now if that makes a difference, let me know what you think, later!!

Brian S

Do what you got to do Steve. There will be that 370hp 327 RX-7 there , and you don't want to get shown up by a piston engine now do you?

OneBadRx7

****, I'm not worried about some frankenstein FREAK, lol...j/k I dont care if I lose or something, I am just looking to get the best times I can without causing any possible damage. Besides its a 327 cubic inch engine, we have an 80 cube engine, just keeping up with him is enough for any of us because it seems to me he has 4 times the motor, lol!!!

Snook

iTrader: (12)

you also dont want to blow the motor
dont listen to this moron (I know what it's like to have the pressure of local friends when going to the track but no race is worth blowing a motor on so if you think there is a chance at all don't do it).

I have the same mods as you as far as intake and full exhaust with midpipe and non sequential all on the pettit unlimited ecu but I also have a pettit streetported motor.

Take this very seriously. Cam from pettit told me never to run more than 13 pounds on pump gas with his unlimited computer because that is really pushing it. I would not run anything more than 13 unless you get racegas and you hookup a wideband and air/fuel to make sure you aren't running lean. I can assure you that running full throttle for the entire 1/4 mile with 15 psi on pump gas is a bad idea and the more runs you do the more dangerous it will be because of the heatsoak.

With your mods you should run very low 12s. I also wouldn't go without drag radials or slicks its basically pointless with our mods.

OneBadRx7

Snook, I am with you 100%, hence I only run 13psi tops, usually. However I was thinking of using some race gas just to see if it made the difference everyone talks about. I am running low 12's as is but would love to hit the 11.99 mark, lol. I dont want to push things too hard so I will most likely just do exacty as you suggested and stick with my 13psi and low 12's, we'll see though. Oh and as far as tires, well I have no slicks nor drag radials but I still seem to do ok for the occasional 12 second run, hehe. Thanks Snook!!

ttb

i would imagine at 15psi your injector duty cycle is going to be 100% and you're asking for trouble. i wouldn't risk it.

OneBadRx7

Thats what I was thinking too, I have know the stock injectors can only handle UP TO 15psi which means to me they couldnt handle it well so maybe I will just run 14.2 or so, not that its a huge difference but to be a little safe anyways, although I dont forsee my motor blowing at a few runs of 15psi, maybe just lessen its life, lol.

BoostCrzy

just leave it....its better to go low 12's 100 times than high 11's one or two.....sounds like your combo is working good...i wouldnt mess with it...

Snook

iTrader: (12)

I don't think you can actually hurt the motor a little. I believe it's either going to chip or blow an apex seal or not going to. Maybe detonation does something to the seal to make it weaker without breaking it that I don't know of?


It seems like you really want to run better times. What are your 60 foot times on street tires? Getting drag radials will help you way more than race gas and 2 more pounds of boost. I say first run some good injector cleaner through your tank before going to the track. Then make sure you burn all of that off and go to the track with hardly any gas at all maybe 1 gallon of 93 and then fill up with 2 gallons of racegas. If you usually run premix don't since it will lower the octane by .000001 % haha. Raise the boost to 14 and nothing higher. Is your wastegate ported? Remember with non seq you will not get spikes but you still will get creep because the wastegate is too small. I get 12 psi in 1st and 2nd gear but then at the end of 3d it goes to 13 and in all of 4th its 13 also on an average temperature day. Borrow dag radials from someone and if you blow the motor I will beat the shizat out of you!!!

Good luck

Trout2

iTrader: (5)

At 13 psi, you're probably getting injector duty cycles in the 90%'s. Don't risk it, keep it at 13 psi and enjoy your motor. Its not worth the down time and money to risk blowing a motor that is still relatively new with only 12k mi.

Save up for a PowerFC and some larger injectors - those are cheaper than a motor.

Jack

Railgun

https://www.rx7club.com/forum/showth...hreadid=179263

See above. I apparently have been doing this since I've had my car (August '02). Course, I haven't driven it for 6 mo. of that period due to other things. I'm getting a manual controller tomorrow or Friday. I don't know if I'm REALLY lucky or not, but to date, I haven't had any problems. See mods below.

Oh yeah, I too have about 12k on a reman and I think about 20k on new stock twins.