hmmm, this doesn't seem right
10-05-2007, 01:26 PM
#53
Senior Member
Join Date: 07-22-05
Location: Quebec City, Quebec
Posts: 1,591
Likes: 0
Received 0 Likes
on
0 Posts
Scaling the MAF for bigger injectors is like running a piggyback or a MAF-T. The only optimal way is to tell the PCM exactly the truth, thus entering the exact flow rate of the injectors in it. That's why I'm still hesitant to put those 63#.
10-05-2007, 04:31 PM
#56
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
just little things here and there, nothing major. nothing to keep me from smacking around some people if needed. it is more on my end than anything else. working on two maps at once fries the brain. gas mileage map with 60's = 35 mpg. race map with 60's = **** gas mileage!
for me the bugs are just figuring thigns out here and there. nothing that would keep some one from running the same map and shitting themselves.
for me the bugs are just figuring thigns out here and there. nothing that would keep some one from running the same map and shitting themselves.
Last edited by Area47; 10-05-2007 at 04:31 PM. Reason: Automerged Doublepost
10-06-2007, 09:52 AM
#58
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
new problem has shown up.
im spraying alky/meth right now.
went home, got on it getting on the highway because people like to hit a 65 mph zone at 40. hit the gas. car doesn't feel right. look down at the afr. 13.0
****!!!!!!!!!!!!!!!
freaked out, got the car home, checked every connection on the water injection. everything works, kicks on at 6 psi.
what im commanding pe wise is what the car is running WITH the meth/alky injection. this is new. hmmmmmmmmmmmmm so i went out for a couple hours and riched the car up to make sure everything was fine, zero knock. egt was in line. everything is good now.
i need to go back and start from scratch on the maf tables, something isn't right.
im spraying alky/meth right now.
went home, got on it getting on the highway because people like to hit a 65 mph zone at 40. hit the gas. car doesn't feel right. look down at the afr. 13.0
****!!!!!!!!!!!!!!!
freaked out, got the car home, checked every connection on the water injection. everything works, kicks on at 6 psi.
what im commanding pe wise is what the car is running WITH the meth/alky injection. this is new. hmmmmmmmmmmmmm so i went out for a couple hours and riched the car up to make sure everything was fine, zero knock. egt was in line. everything is good now.
i need to go back and start from scratch on the maf tables, something isn't right.
10-06-2007, 09:56 AM
#59
welcome to the wonderful world of cobalts man lol.
check the new race in my turbo thread. but anyway, car did something really wierd this morning, doing a 2nd gear pull getting on the highway today, and all of a sudden my afr leaned completely out... like 20:1 car r broke up, I let off, then it went back to normal, plus I've been having random misfires. I think it may be time for new injectors.
check the new race in my turbo thread. but anyway, car did something really wierd this morning, doing a 2nd gear pull getting on the highway today, and all of a sudden my afr leaned completely out... like 20:1 car r broke up, I let off, then it went back to normal, plus I've been having random misfires. I think it may be time for new injectors.
LTFT goes from +10 to -10 no matter how many times i recalibrate it. i think i will go buy some MAF cleaner and see if that helps.
10-06-2007, 11:14 AM
#61
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
welcome to the wonderful world of cobalts man lol.
check the new race in my turbo thread. but anyway, car did something really wierd this morning, doing a 2nd gear pull getting on the highway today, and all of a sudden my afr leaned completely out... like 20:1 car r broke up, I let off, then it went back to normal, plus I've been having random misfires. I think it may be time for new injectors.
check the new race in my turbo thread. but anyway, car did something really wierd this morning, doing a 2nd gear pull getting on the highway today, and all of a sudden my afr leaned completely out... like 20:1 car r broke up, I let off, then it went back to normal, plus I've been having random misfires. I think it may be time for new injectors.
no car i have ever worked on, or tuned has done this. i was commanding 13.0 to run 12.0 now the cmnd turns into actual? oh no, thats not right captain. we're not having that. no wonder these cars blow up
im seriously going to load my original maf tables in the car, and leave it alone. ever since i started messing with those. the car has not acted right. it never had a problem before i got the bright idea of tweakin the maf table to "approved" numbers, AND to top it off. my gas mileage went into the toilet
Last edited by Area47; 10-06-2007 at 11:14 AM. Reason: Automerged Doublepost
10-06-2007, 11:31 AM
#62
this is seriously starting to annoy the **** out of me.
no car i have ever worked on, or tuned has done this. i was commanding 13.0 to run 12.0 now the cmnd turns into actual? oh no, thats not right captain. we're not having that. no wonder these cars blow up
im seriously going to load my original maf tables in the car, and leave it alone. ever since i started messing with those. the car has not acted right. it never had a problem before i got the bright idea of tweakin the maf table to "approved" numbers, AND to top it off. my gas mileage went into the toilet
no car i have ever worked on, or tuned has done this. i was commanding 13.0 to run 12.0 now the cmnd turns into actual? oh no, thats not right captain. we're not having that. no wonder these cars blow up
im seriously going to load my original maf tables in the car, and leave it alone. ever since i started messing with those. the car has not acted right. it never had a problem before i got the bright idea of tweakin the maf table to "approved" numbers, AND to top it off. my gas mileage went into the toilet
why cant anything work like its supposed to?
10-06-2007, 11:52 AM
#63
Senior Member
Join Date: 07-22-05
Location: Quebec City, Quebec
Posts: 1,591
Likes: 0
Received 0 Likes
on
0 Posts
this is seriously starting to annoy the **** out of me.
no car i have ever worked on, or tuned has done this. i was commanding 13.0 to run 12.0 now the cmnd turns into actual? oh no, thats not right captain. we're not having that. no wonder these cars blow up
im seriously going to load my original maf tables in the car, and leave it alone. ever since i started messing with those. the car has not acted right. it never had a problem before i got the bright idea of tweakin the maf table to "approved" numbers, AND to top it off. my gas mileage went into the toilet
no car i have ever worked on, or tuned has done this. i was commanding 13.0 to run 12.0 now the cmnd turns into actual? oh no, thats not right captain. we're not having that. no wonder these cars blow up
im seriously going to load my original maf tables in the car, and leave it alone. ever since i started messing with those. the car has not acted right. it never had a problem before i got the bright idea of tweakin the maf table to "approved" numbers, AND to top it off. my gas mileage went into the toilet
10-06-2007, 11:58 AM
#64
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
ugh!
im loading my stock maf files later and going from there.
10-06-2007, 12:30 PM
#66
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
i'll get it figured out today. besides, my numbers are going to be massivly skewed later anyways, so this should be even more fun
10-08-2007, 10:49 AM
#71
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
i figure im going to have to tweek the table some when i put the new tb on the car this week. we shall see. i guess i was exceeding the happy window
10-11-2007, 02:19 AM
#72
I'm inclined to agree with
Stage III w/100 octane = 260H/P w/50 shot of nitrous = 310 + H/P - all w/42# Stage II injectors, with the factory Stage III calibration.
My boost experience was with a 1987 Buick GN - (On the GN 43.5# injectors are good for 500+ H/P), and a 1991 GMC Syclone, and a 1992 GMC Typhoon.
2007 Shelby GT500 has 52# injectors which with the proper fuel delivery system updates/Stage Kits available through Kenne Bell can produce from 540 to 801 RWHP, with the 52# injectors.
Bigger isn't always better. Unless you have enough/a very good/properly balanced fuel delivery system/pump/properly adjusted fuel pressure/regulator etc., with bigger injectors there is a possibility you might actually end up with less fuel when using larger injectors. The bigger the injectors the more fuel pressure required, kinda like a garden hose, with a large opening or a small opening. It gets into some real science trying to properly balance all that let me tell you. It's not just a matter of sticking bigger injectors in and that is the end of it. That is just the beginning. Then of course there are the tuning/calibration issues that follow.
The point I am trying to make is everything has to be balanced and up to snuff for maximum efficiency. Just throwing 60# injectors on a moderately modified engine is like sticking an 1100 cfm carb on an engine that you put some moderate go fast parts on, that previously had a 650 cfm carb on it. Winning drag racers learned a long time ago to not over carburate their engines. They run much better with properly sized carburetors.
It wouldn't surprise me if some of the folks running 60# injectors ,who don't know what they are doing, if they are getting enough F/P, might have raw fuel dripping out of their tailpipe at worst, or raw fuel going into the oil at best, neither of which are good. (Assuming the factory fuel system is able to keep up with almost twice the size injectors that come on the LSJ.)
If it is working for anyone out there, more power to you. IMHO, unless you have an extremely modified LSJ, you may be hurting more than you are helping, and are likely wasting a lot of fuel, and might possibly even be creating catastrophic engine problems down the road.
Good luck.
Doc
Last edited by mrdoc442; 10-11-2007 at 01:51 PM.
10-11-2007, 07:17 AM
#73
just also remember they are making that kind of power on 2x the cylinders and over 2x the displacement. which is why they require smaller injectors.
BTW I do need the 60's actually gonna need larger, still on 18psi with the turbo, 44.48 ve airflow (lb/min) maf reading 47.80 lb/min. Hitting over 90% idc on the 60's now and only at 18 psi, tuning it to 21 tomorrow to see what happens.
BTW I do need the 60's actually gonna need larger, still on 18psi with the turbo, 44.48 ve airflow (lb/min) maf reading 47.80 lb/min. Hitting over 90% idc on the 60's now and only at 18 psi, tuning it to 21 tomorrow to see what happens.
10-11-2007, 10:59 AM
#74
Rent me! per hour
Thread Starter
Join Date: 03-22-07
Location: Still fixing others mistakes.
Posts: 24,185
Likes: 0
Received 20 Likes
on
14 Posts
you're failing to see that this is a returnless system. larger injectors are required to get power out of them. we don't have the ability to crank the fuel pressure, over drive the injectors, and go have fun.
10-11-2007, 02:19 PM
#75
Thank you for your
just also remember they are making that kind of power on 2x the cylinders and over 2x the displacement. which is why they require smaller injectors.
BTW I do need the 60's actually gonna need larger, still on 18psi with the turbo, 44.48 ve airflow (lb/min) maf reading 47.80 lb/min. Hitting over 90% idc on the 60's now and only at 18 psi, tuning it to 21 tomorrow to see what happens.
BTW I do need the 60's actually gonna need larger, still on 18psi with the turbo, 44.48 ve airflow (lb/min) maf reading 47.80 lb/min. Hitting over 90% idc on the 60's now and only at 18 psi, tuning it to 21 tomorrow to see what happens.
The Buick GN and Sy/Ty's are V-6's, @ 3.8L and 4.3L respectively, and were Tech I, chip controlled. The GT500 is 5.4L., and of course the LSJ are Tech II controlled, and a little more difficult for the average enthusiast to calibrate. A little like burning your own chip for the old Tech I vehicles.
Your application likely doesn't apply to the average LSJ enthusiast on this Forum.
That being said, it might be worthwhile looking into the Boost-a-Pump offered by Kenne Bell for the GT500, which enables it to reach the H/P numbers I mentioned. I don't know if it would help the LSJ, but maybe he might have an idea what might.
Regardless of displacement, the principles are the same. As H/P goes up, fuel pressure and volume must go up proportionally, (usually # per # of boost) or you risk running lean, and destroying your engine. W/60# injectors, the fuel pressure must also increase in order to properly supply the new volume demand. If the factory LSJ pump is able to do this with no modification, it is the first factory pump I know of that can. I do not claim to be an LSJ master tuner, or GN or Sy/Ty master tuner for that matter, although I played with the turbos quite a bit, and have modified my 06 Cobalt SS/ S/C W/Stage II, 2P/E, CAI, Ex Honed E/M, Perf C/B, 2.8 etc. for street use. I also have a 71 Olds Cutlass 442 Super Gas drag car with a big block that runs mid 10's at 5/6K D/A, would be in the 9's @ sea level. I also had a 1991 Olds Calais Quad442 w 2.3L, which in some ways was the predecessor to the ECOtech. Though the Quads had their issues, they were sweet running little engines. I bought that car froma little old lady in Iowa. It had 30K miles on it, with the exterior/interior/engine in perfect condition. I put a W-41 chip in it, dualed it out, Ram Air CAI, and it was a screamer. I hated to part with it, but I traded it in on the Cobalt, so it went for a higher cause. As far as I know the late Jim Feuling's Quad 4 still holds the record for highest specific output of any automotive engine with a twin turbo Quad 4 2.0 L. BE4 (smaller than the 2.3 L.) - over 1270 H/P from 121 C/I. He was far ahead of his time and a great loss to the motor sports world. I won't bore you with all the cars I have had, but, I pretty much came up from old school high performance, and slowly but surely into the computer controlled vehicle technology of the 80's/90/s up to today.
I'd suggest that you consider picking Kenne Bell, and some of the other master turbo V-6 tuner Gurus, brains to expand your turbo knowledge areas. Though their primary expertise was initially with V-6 engines, I'm sure they are playing with the 4/cyl's a lot more by now, and the wealth of turbo knowledge they gained/turbo principles etc., would apply to a turbo LSJ.
Good luck.
Doc
Last edited by mrdoc442; 10-11-2007 at 03:10 PM.