timing advise on twin 70mm blowthru carb a2w meth injected pumpgas 5.3 :)
04-21-2014, 11:52 PM
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timing advise on twin 70mm blowthru carb a2w meth injected pumpgas 5.3 :) Lol yeah i built a weird one but need timing advise on my cam to get the best throttle response and spooltime.here is my setup:
5.3lm7 with studs and rod bolts gapped rings
750ban with brpv on primary
Large a2w ic 50-60* lake water cooled with twin on3 70mm .81 ar turbines on up and forward headers, twin 60mm gates, 50mm bov on ic inlet
a.i.s. meth injection after ic core, pure meth at 14gph thru a single a.i.s. nozzle
pumpgas 93
228r tsp on 112lsa,ls7 lifters,comp 7.425 p.rods,elgin beehives at 150seat 400 open
the plan is to drag race the boat 1/8th(660) in 10days at a local lake race me and some pals are putn on and id like some advise on ignition timing.i run msd6012 controller with truck coils.normally i jus keep idle around 900-1000rpms and 15* timing at that idle and ramp it quickly and lock it at 29* until the 2bar map see's boost amd drags timing down to 15* by 7lbs.no gears to shift, my pump see's full load in just ft and stays that way till the finish line. No iat gauge but surely with 50* water thru the big ic and then gtn hit with methanol as it leaves the ic wld bring me well below ambient charge temps in the intake.i feel the 15* is safe but i can only control up to 15lbs before the 2bar map table drops off so i was wondering am i safe at 15* up to say 7200rpm on 18lbs or do i need to back it down alil? I appreciate advise guys!
5.3lm7 with studs and rod bolts gapped rings
750ban with brpv on primary
Large a2w ic 50-60* lake water cooled with twin on3 70mm .81 ar turbines on up and forward headers, twin 60mm gates, 50mm bov on ic inlet
a.i.s. meth injection after ic core, pure meth at 14gph thru a single a.i.s. nozzle
pumpgas 93
228r tsp on 112lsa,ls7 lifters,comp 7.425 p.rods,elgin beehives at 150seat 400 open
the plan is to drag race the boat 1/8th(660) in 10days at a local lake race me and some pals are putn on and id like some advise on ignition timing.i run msd6012 controller with truck coils.normally i jus keep idle around 900-1000rpms and 15* timing at that idle and ramp it quickly and lock it at 29* until the 2bar map see's boost amd drags timing down to 15* by 7lbs.no gears to shift, my pump see's full load in just ft and stays that way till the finish line. No iat gauge but surely with 50* water thru the big ic and then gtn hit with methanol as it leaves the ic wld bring me well below ambient charge temps in the intake.i feel the 15* is safe but i can only control up to 15lbs before the 2bar map table drops off so i was wondering am i safe at 15* up to say 7200rpm on 18lbs or do i need to back it down alil? I appreciate advise guys!
Last edited by IMPATIENT 1; 04-21-2014 at 11:59 PM.
04-22-2014, 12:12 AM
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Forgot to mention the jetpump acts like a 3k stall basically.i can flash my pump to 7200 leaving and itll settle 200rpms less in about 30ft from the hit
there is no way to stage spool in a boat, yet
im working on that tho.thinking about revving the motor to 2500rpms on the 2step with pump in nuetral(its still pumping but thrust isnt directed backwards to propel boat forward, at that rpm pump will absorb @ 200hp like a brake dyno wld) and as my 2step is banging at 2500 turn the meth injection on to enrichen to really make some drive pressure while sitting still..if it works ill build alil boost before hitting a switch which turns off the 2step and put the boat in forward thrust at same time effectively leaving on boost from the hit. any suggestions on how to improve leaving? I know most here arent boat racers but yall know more than i do about prestaging turbo motors.i welcome any input
there is no way to stage spool in a boat, yet
im working on that tho.thinking about revving the motor to 2500rpms on the 2step with pump in nuetral(its still pumping but thrust isnt directed backwards to propel boat forward, at that rpm pump will absorb @ 200hp like a brake dyno wld) and as my 2step is banging at 2500 turn the meth injection on to enrichen to really make some drive pressure while sitting still..if it works ill build alil boost before hitting a switch which turns off the 2step and put the boat in forward thrust at same time effectively leaving on boost from the hit. any suggestions on how to improve leaving? I know most here arent boat racers but yall know more than i do about prestaging turbo motors.i welcome any input Last edited by IMPATIENT 1; 04-22-2014 at 12:24 AM.
04-22-2014, 08:43 AM
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04-22-2014, 01:35 PM
#6
What year 5.3?
I'd drop it down to 11* or so and add boost until you hit your goal. Then add timing slowly while reading the plugs.
From what I've seen of blow through setups with semi large overlapping cams, I'd guess you would be fine at 15*. Esp. with all that intercooling and massive amount of turbo.
Where's the pictures!
I'd drop it down to 11* or so and add boost until you hit your goal. Then add timing slowly while reading the plugs.
From what I've seen of blow through setups with semi large overlapping cams, I'd guess you would be fine at 15*. Esp. with all that intercooling and massive amount of turbo.
Where's the pictures!
04-22-2014, 04:29 PM
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im sorry guys cant post pix from my cell
cam will be delivered thursday and ill fire it off friday, test passes sunday. lm7 03 motor.it did 108 in 900ft with the non ic s480 setup with meth injection but small turbine choked it at 6900 so i made a cam change and went to up and forwards with twins and a2w.ill get pix this wknd and email them to one of you guys.turned out pretty cool and i kept plumbing to a minimum. Trending Topics
04-22-2014, 05:10 PM
#8
I would be kinda on the side of Forcefed86 here. I would start down around 10-11 at peak boost and rise up to around 12-13 towards redline and slowly advance it and see how it reacts. Mine right now is around 10 at peak boost and rising to around 14-15 at redline. I am sure I could make more with more timing, but I am comfortable where it is. If you were going on extended cruising at WOT, I would say be REAL careful, but for just short blasts it should be fine.
04-22-2014, 10:27 PM
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Ok guys ill write a timing file tmrw with 13* after 7lbs if yall think itd be safer..pretty sure ill hity target rpm at about 16-17lbs but i may only get one lake trip in before the race so ill do as suggested and leave it low and hit it with 18lbs and call it good for the 660, it does what it does.
what about outta boost? I know im hurtn spool by locking the timing at 29* after 2500 till boost starts retarding the map table.i know too much advance can also hurt throttle respnse just as much as too lil advance.im all ears, gtn some good advise and.i appreciate it!
what about outta boost? I know im hurtn spool by locking the timing at 29* after 2500 till boost starts retarding the map table.i know too much advance can also hurt throttle respnse just as much as too lil advance.im all ears, gtn some good advise and.i appreciate it!
04-22-2014, 10:46 PM
#10
1. Get yourself a 3 bar map sensor.
2. I think you could run more timing below the rpm where your drive loads the engine , maybe 32*.
3 - building boost before the run. I dont know how your trans/drive works, but it sounds like you can shift it into gear after building boost? If so, its just like my stick shift car. Use 2 step AND the nitrous timing retard built into the 6012 at same time. It will pop and bang like a ****, but building boost will be easy.
I run 16* in my 6.0 @16-17 psi. Its blowthrough on 100 octane gas, non intercooled, spraying 1 10gph nozzle, and 2#2 nozzles of 50/50 water meth.
2. I think you could run more timing below the rpm where your drive loads the engine , maybe 32*.
3 - building boost before the run. I dont know how your trans/drive works, but it sounds like you can shift it into gear after building boost? If so, its just like my stick shift car. Use 2 step AND the nitrous timing retard built into the 6012 at same time. It will pop and bang like a ****, but building boost will be easy.
I run 16* in my 6.0 @16-17 psi. Its blowthrough on 100 octane gas, non intercooled, spraying 1 10gph nozzle, and 2#2 nozzles of 50/50 water meth.
04-23-2014, 06:46 AM
#11
Ok guys ill write a timing file tmrw with 13* after 7lbs if yall think itd be safer..pretty sure ill hity target rpm at about 16-17lbs but i may only get one lake trip in before the race so ill do as suggested and leave it low and hit it with 18lbs and call it good for the 660, it does what it does.
what about outta boost? I know im hurtn spool by locking the timing at 29* after 2500 till boost starts retarding the map table.i know too much advance can also hurt throttle respnse just as much as too lil advance.im all ears, gtn some good advise and.i appreciate it!
what about outta boost? I know im hurtn spool by locking the timing at 29* after 2500 till boost starts retarding the map table.i know too much advance can also hurt throttle respnse just as much as too lil advance.im all ears, gtn some good advise and.i appreciate it!
This is the OEM timing map for an LS1... Out of boost I'd make mine similar to this...
04-23-2014, 10:53 AM
#12
1. Get yourself a 3 bar map sensor.
2. I think you could run more timing below the rpm where your drive loads the engine , maybe 32*.
3 - building boost before the run. I dont know how your trans/drive works, but it sounds like you can shift it into gear after building boost? If so, its just like my stick shift car. Use 2 step AND the nitrous timing retard built into the 6012 at same time. It will pop and bang like a ****, but building boost will be easy.
I run 16* in my 6.0 @16-17 psi. Its blowthrough on 100 octane gas, non intercooled, spraying 1 10gph nozzle, and 2#2 nozzles of 50/50 water meth.
2. I think you could run more timing below the rpm where your drive loads the engine , maybe 32*.
3 - building boost before the run. I dont know how your trans/drive works, but it sounds like you can shift it into gear after building boost? If so, its just like my stick shift car. Use 2 step AND the nitrous timing retard built into the 6012 at same time. It will pop and bang like a ****, but building boost will be easy.
I run 16* in my 6.0 @16-17 psi. Its blowthrough on 100 octane gas, non intercooled, spraying 1 10gph nozzle, and 2#2 nozzles of 50/50 water meth.
04-23-2014, 02:01 PM
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04-23-2014, 10:58 PM
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04-27-2014, 02:24 AM
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Lil update.i started it today and wholly crap did the new twin setup and cam improve throttle response!! Its never been so snappy. i had to set idle afr on carb to 12.5 cuz i need more accelerator pump(50cc kit on the way) then i can lean idle out on the lake with the motor at idle load and it shld be just as crisp but cleaner idle to keep my cold br7ef plugs hot lol. i run the motor on the hose tday(sunday) and someone wants ill shoot ya a cell vid.i like to let my boat motors spend time runnin on the ttailer prior to taking it to what.i put on a cheap delco pf48 filter so i cld take it to work monday and cut it open for inspection after a hr of trailer run time.if alls good it off to the lake this wk to set the gates for the race this wknd here locally.see if itll withstand 18lbs 660ft passes from the twins 70mm turbs on intercooled and meth injected pumpgas.im taking detonation control seriously!