Ok so I have a blown 6-bolt on my hands here, and I'm really wanting to get deep into the 12s. Oh yeah and funding is limited...go figure. Now I'm not trying to be a bench-racer here or anything, but in your opinions do you guys think that some forged pistons (probably wiseco or ross) and the 6-bolt big rods could get me well into the 12's and still be somewhat reliable? Thanks. Oh and on a side note my 6 bolt seems to have been expirencing a little crank walk, kinda suprised/scared me when I took it out.

Stock 1g pistons and rods will get you well beyond 12's in an AWD DSM.

Don't worry about going forged for 12's. Save your cash and get stock pistons/rods and get to tuning. Tuning is what will get you there.


Also, crankwalk has happened to less than a handful of 6-bolts in their history. Are you sure it was CW?

ok well then what are the limits of the stock pistons and big rods? Oh and maybe it isn't crank walk, I'm not totally for sure what it is. All I know is that when i was trying to take the clutch off I pulled it and noticed that the whole crank would move more than I thought it should. I could just push it back and pull it out repeatedly. I looked at the dampner pulley to make sure it was moving and not just a problem with the clutch/flywheel or something, and the dampner was moving too.

Stock pistons/rods are good to ~400+ hp with the tuning as the most important factor of their limit. Many people have gone into the 11's on stock pistons/rods. Shit even a heavily modded car with stock turbo has run mid 11's. Getting 2g pistons with 1g rods is a common application too. 2g pistons are higher compression and are used to make some more power with the 1g rods as a beefier partner. That's another option to consider.

Maybe it is crankwalk, but that would be a rarity. Get a feeler gauge and check the play in the crank when you press the clutch. It very well may be, but again, you would be among a select few. Doesn't mean it's impossible though.

Fastest 7 bolt stock block (factory pistons and rods) is 11.2 at 129 or so. Stock 6 bolt blocks run into the 10's reliably. If your block was experiencing crankwalk, that means it is just normal bearing wear. Crankwalk is just premature bearing wear. Generally a 14 year old 6 bolt block will not have crankwalk but typical bearing wear.

My 6bolt block has 184k miles on it and when I tore it apart it had about 1/8" of back and forth play in the crank. I knew it was from normal wear on a car that had 20 psi ran on it daily. The crank bearings were pretty ugly when I took them out. I should see if I still have them and post up some pics for reference.

well this engine was rebuilt about 6k miles ago, so yea it was pretty premature wear. wish i hadn't been an idiot and drove the piss out of it when it was knocking, but I didn't think rich knock was such a big deal as lean knock. oh well live and learn, then kick yourself in the ass...really hard. The thing about the 2g pistons is that I live in a small hick town and there isn't a maching shop nearby to machine the rod end down, so I just thought I could save myself the hassle of finding one and order forged pistons. I'd LIKE to break into the elevens, but I don't know if I want to dish out the money to do that, especially with the high gas prices.

Anywho right now I have a 119k mile salvage yard replacement engine in my car that the rear main seal decided to crap out on as soon as i put it in the car, and I have it set at stock boost about 10~11 psi and I'm trying to get it tuned nicely, but I think I maxed out my injectors, what do you all think? here's the log

TIMA O2-R TPS RPM KNCK INJP ---
26° 0.02V 47.8% 1469 0 6.91ms 10
22° 0.84V 71.0% 1531 0 7.42ms 12
20° 0.84V 85.5% 1563 0 7.42ms 12
18° 0.82V 96.1% 1563 0 7.68ms 12
18° 0.86V 100.0% 1563 0 7.68ms 12
18° 0.86V 100.0% 1594 0 7.94ms 13
18° 0.86V 100.0% 1656 0 7.94ms 14
18° 0.86V 100.0% 1688 0 7.68ms 13
18° 0.84V 100.0% 1688 0 7.68ms 13
18° 0.82V 100.0% 1719 0 7.68ms 14
18° 0.80V 100.0% 1750 0 7.68ms 14
19° 0.70V 100.0% 1781 0 7.68ms 14
18° 0.57V 100.0% 1813 0 7.94ms 15
18° 0.59V 100.0% 1844 0 7.94ms 15
18° 0.68V 100.0% 1875 0 7.94ms 15
18° 0.66V 100.0% 1938 0 8.19ms 16
19° 0.64V 100.0% 1938 0 8.19ms 16
19° 0.43V 100.0% 1969 0 8.19ms 17
17° 0.43V 100.0% 2031 0 8.19ms 17
18° 0.41V 100.0% 2063 0 8.45ms 18
19° 0.57V 100.0% 2094 0 8.45ms 18
19° 0.68V 100.0% 2125 0 8.45ms 19
19° 0.51V 100.0% 2156 0 8.70ms 20
19° 0.74V 100.0% 2219 0 8.96ms 21
19° 0.74V 100.0% 2250 0 8.70ms 20
19° 0.68V 100.0% 2281 0 9.22ms 22
18° 0.78V 100.0% 2313 0 9.22ms 22
17° 0.76V 100.0% 2344 0 9.22ms 23
18° 0.82V 100.0% 2406 0 9.47ms 24
18° 0.74V 100.0% 2438 0 9.73ms 25
17° 0.78V 100.0% 2500 0 9.98ms 26
16° 0.82V 100.0% 2563 0 10.50ms 28
16° 0.80V 100.0% 2594 0 11.26ms 31
15° 0.84V 100.0% 2656 0 11.78ms 33
15° 0.84V 100.0% 2750 0 12.80ms 37
14° 0.86V 100.0% 2813 0 13.57ms 40
13° 0.86V 100.0% 2844 0 14.59ms 44
14° 0.86V 100.0% 2938 0 14.59ms 45
14° 0.88V 100.0% 2938 7 14.59ms 45
13° 0.88V 100.0% 3063 7 14.85ms 48
14° 0.88V 100.0% 3094 6 14.59ms 48
14° 0.88V 100.0% 3156 6 14.85ms 50
14° 0.88V 100.0% 3188 6 14.59ms 49
14° 0.88V 100.0% 3219 6 14.59ms 50
15° 0.88V 100.0% 3344 5 14.34ms 51
15° 0.86V 100.0% 3469 5 14.59ms 54
15° 0.86V 100.0% 3469 5 14.85ms 55
15° 0.88V 100.0% 3469 6 14.85ms 55
14° 0.86V 100.0% 3531 5 14.85ms 56
16° 0.86V 100.0% 3625 5 14.85ms 57
16° 0.86V 100.0% 3781 5 14.85ms 59
15° 0.88V 100.0% 3781 5 15.10ms 61
16° 0.88V 100.0% 3781 4 15.36ms 62
15° 0.88V 100.0% 3813 4 15.36ms 62
15° 0.86V 100.0% 3938 4 15.62ms 65
16° 0.86V 100.0% 4000 4 15.87ms 67
16° 0.86V 100.0% 4031 3 16.64ms 71
17° 0.86V 100.0% 4156 3 16.38ms 72
17° 0.88V 100.0% 4188 3 16.90ms 75
17° 0.86V 100.0% 4250 3 16.64ms 75
17° 0.86V 100.0% 4313 2 16.90ms 77
17° 0.86V 100.0% 4438 3 17.15ms 81
17° 0.86V 100.0% 4375 3 17.41ms 81
17° 0.86V 100.0% 4500 3 17.66ms 84
17° 0.86V 100.0% 4656 2 17.66ms 87
17° 0.86V 100.0% 4750 2 17.92ms 90
17° 0.86V 100.0% 4531 2 18.69ms 90
18° 0.86V 100.0% 4750 2 18.18ms 92
18° 0.86V 100.0% 4813 1 18.69ms 96
18° 0.86V 100.0% 5000 1 19.20ms 102
18° 0.86V 100.0% 5031 1 19.20ms 103
18° 0.86V 100.0% 4875 1 19.46ms 101
20° 0.86V 100.0% 4906 0 18.94ms 99
19° 0.86V 100.0% 5250 0 19.46ms 109
19° 0.86V 100.0% 5094 0 19.71ms 107
19° 0.86V 100.0% 5156 0 19.97ms 110
20° 0.86V 100.0% 5156 0 20.74ms 114
20° 0.86V 100.0% 5313 0 20.74ms 117
21° 0.86V 100.0% 5406 0 20.99ms 121
22° 0.86V 100.0% 5469 1 21.76ms 127
21° 0.84V 100.0% 5375 0 21.76ms 124
21° 0.84V 100.0% 5406 0 22.27ms 128
23° 0.84V 100.0% 5563 0 22.27ms 132
23° 0.84V 100.0% 5531 0 23.04ms 136
22° 0.84V 100.0% 5875 0 23.55ms 147
23° 0.84V 100.0% 5531 0 23.30ms 137
22° 0.84V 100.0% 5719 1 23.55ms 143
21° 0.84V 100.0% 5781 1 23.81ms 147
22° 0.84V 100.0% 5969 0 24.06ms 153
23° 0.84V 100.0% 5781 0 23.55ms 145
23° 0.84V 100.0% 5969 0 24.58ms 156
24° 0.84V 100.0% 5938 0 24.58ms 155
23° 0.84V 100.0% 6000 0 25.86ms 165
22° 0.84V 100.0% 6063 4 25.34ms 164
21° 0.84V 100.0% 6094 4 25.86ms 168
22° 0.84V 100.0% 6156 11 25.60ms 168
18° 0.84V 100.0% 6094 11 25.60ms 166
16° 0.82V 100.0% 6094 16 25.09ms 163
17° 0.82V 100.0% 6219 15 26.11ms 173
14° 0.82V 100.0% 6125 24 24.83ms 162
14° 0.82V 100.0% 6188 24 24.83ms 164
14° 0.82V 100.0% 6094 24 23.30ms 151
14° 0.82V 100.0% 6344 24 23.81ms 161
11° 0.82V 100.0% 6531 23 22.53ms 157
14° 0.82V 49.0% 6469 23 4.10ms 28
23° 0.80V 10.6% 6031 0 2.05ms 13

What do you all think? oh yeah i have a 255lb/hr fuel pump, apex DP and Cat-back, K&N with hacked can, and SAFC I and boost starts to creep quite a bit in the upper rpm's. Thanks a log guys

I almost forgot to give my SAFC settings...

RPM 3k..4k..5k...5.5k..6k...7k
Cor +5 +9 +10 +20 +40 +45

Those are all on the high side

anybody?

Your knock counts and O2's say you are too lean. You have big end (High RPM) knock and your O2's are dipping into the low .80's. Richen up and it should improve. Also your timing is being pulled by 10* or so when this is happening. It should be in the low to mid 20*'s when tuned correctly.

What injectors again? Also, what are your compression numbers? Also, what about this boost creep problem you mentioned? Stock turbo with the 3" exhaust? Did you port the turbo to eliminate the creep? (Sorry if you've answered these before. I can't keep up with everyones setup.)

Stock 450 injectors, haven't checked compression(guess i should really do that), boost is creeping to about 15-16psi, stock 14b and 02 housing with 3in exhaust(slight porting on 02, but didn't help much) also I have some 650 injectors, but I'd kind of like to get everything lined out with the stock ones to make sure everything is going to work ok. Thanks

EDIT: I just remembered that I have the smaller honeycomb removed, not sure if that makes a big difference or not though

Originally posted by sd240
Stock 450 injectors, haven't checked compression(guess i should really do that), boost is creeping to about 15-16psi, stock 14b and 02 housing with 3in exhaust(slight porting on 02, but didn't help much) also I have some 650 injectors, but I'd kind of like to get everything lined out with the stock ones to make sure everything is going to work ok. Thanks EDIT: I just remembered that I have the smaller honeycomb removed, not sure if that makes a big difference or not though

You need to port the shit out of the 02 housing and flapper hole to get it to work without boostcreep.

Originally posted by HybriDSM

Originally posted by sd240 Stock 450 injectors, haven't checked compression(guess i should really do that), boost is creeping to about 15-16psi, stock 14b and 02 housing with 3in exhaust(slight porting on 02, but didn't help much) also I have some 650 injectors, but I'd kind of like to get everything lined out with the stock ones to make sure everything is going to work ok. Thanks EDIT: I just remembered that I have the smaller honeycomb removed, not sure if that makes a big difference or not though

You need to port the shit out of the 02 housing and flapper hole to get it to work without boostcreep.

I had to add a machine a bigger flapper and add a tubular o2 dump housing to get rid of my creep on my 16G. Now it stays rock solid at whatever I set it at.

You dont have to get the rods machined anymore. Nippon racing is making 2G style pistons that fit stock 1G rods. They are also a bit better quality than the stock 2G's. Also, any type of detonation/preignition is bad, period. It murders ring lands, hammers rod bearings and generally reaks havoc on engines. They showed us at school high speed videos taken inside a specially prepped head of the normal combustion process, then one detonating. Very violent explosion causing pressure peaks up to 20X that of normal combustion. Preignition is probably the worst because it detonates before the piston has reached top dead center, and this is bad news for the big ends of the rod and the rod journals on the crank.