piston questions on what i have read.

[turbhoe]

i hope this is the right section. i didn't find a engine section.

well in my studies of the lbz i see alot of people complaining about the stock pistons. saying they crack easy and don't hold power. but at the same time i see people making alot of power on them with no issues.

my question are: one, are they really that much weaker or are guys buying new trucks and just over timing them and not tuning them right?
two, how many people make good power with the stock lbz's? by good power i mean 500-650whp. i currently make over 600 with my 5.3 and if i swap to a duramax i don't want to have to down grade my hp numbers.

now understand, i'm not asking for 650whp everyday running it to the max all the time. i mean 650 for track days or for when that mustang pisses me off and i need some attitude. daily i'd like to have 500 on hand but i won't be nailing it at every stop light. my daily hp now are around 500 on low boost. in the ls world of things we have people complain about pistons but its usually because they over tune or don't have a good setup and they pop pistons like candy.

i hope my questions make since, i can explain better as we go along.
note: my first mod will be a trans. i learned my lesson on this first hand.

 

[TeaBagger2006]

in my opinion i think its just luck. either they crack or they dont. plenty of stock lbz running around making over 500. the lly/lb7 pistons crack too, so like i said i think its just luck

 

[turbhoe]

bad luck and bad tuning?

 

[hondarider552]

pistons crack on stock tunes, pistons crack on 500hp, some last till 700hp you dont really ever know, tuning does play a big role in the pistons living, but they go when they want to go. my buddies LBZ popped a piston a month ago pulling out of a mcdonalds parking lot merging with traffic. it's weird how they let go.

 

[Kat]

bad luck and bad tuning?

I think it's the luck of the draw....

 

[turbhoe]

well if your a lucking one, is the rest of the lbz good for those power levels.

 

[JoshH]

500 HP in a Duramax is a lot different than 500 HP in a Tahoe. A legitimate 500 HP in a typical Duramax pickup would probably only be about a half a second behind the time you have posted in your sig and probably more than 1000 lbs heavier.

 

[WolfLMM]

well if your a lucking one, is the rest of the lbz good for those power levels.

Yes, assuming you don't beat the snot out of it.

At 600hp you should consider billet rods. Tuning plays a big role in how the stock rods fare.

 

[turbhoe]

500 HP in a Duramax is a lot different than 500 HP in a Tahoe. A legitimate 500 HP in a typical Duramax pickup would probably only be about a half a second behind the time you have posted in your sig and probably more than 1000 lbs heavier.

see these are things i've been trying to find answers for. like where does torque play in at the quarter mile? you would think, 500 to 500 if one truck has 500lbft and the other has 1000, that the higher torque would win. given same weight and all. my hoe as is weighed 6020lbs on that 12.33 run. after a dmax swap i figure i'm looking at 6500-7000lbs. will i still be able to run low 12's?
my main wants from the swap is WAY better towing and WAY better mpg's along with cool factor. but i don't want to loose out on my quarter mile trips (obviously different tunes for different times)

 

[JoshH]

Take a look at the 25 quickest stock Duramax list. These are all stock motor trucks that are running anywhere from 12.6 to 12.1 with the only real power adders being a tuned ECM, exhaust, and intake mods.

 

[turbhoe]

true, i looked at those and it looked promising with me being lighter and i already have water/meth on my truck now that will be carried over. i thought about using my turbo for a low pressure turbo on the dmax but i was told the .96 a/r t4 exhaust would be too small even though its a 78mm compressor. i thought gating it would work to lower drive pressure but i guess not.

 

[turbhoe]

i'm really looking forward to this. i think it will be am awesome swap. and surely i can get better than 13mpg. lol

 

[duratothemax]

There is no way your tahoe will weigh anywhere near 7,000lbs with a duramax swap. Im really surprised yours weighs 6020lbs as it sits. Thats a couple hundred pounds more than a stock 1500 suburban. What heavy stuff do you have in it? Was that 6020lbs with you in the driver seat?

What are you going to do for a transmission/transfer case? Swap the allison and np263 in place of the 4L60 and borgwarner awd case?

I assume your tahoe is one of those oddballs with the "selectable awd + low range" transfer case and stabilitrak? They only had that setup for 1 year as far as I know...in 05 they went back to the normal autotrac case, even for the SUV's that also had stabilitrak. Stabilitrak will not work with the duramax ECM, so you will either have to swap to the older non-stabilitrak 3-channel ABS setup, or just deal with the "SERVICE STABILITY SYS" message in the driver info center.

With a little over 500rwhp duramax your tahoe should easily run mid/low 12's.

Duramax weighs 837lbs.

 

[WolfLMM]

It will be a fun ride for sure! Good luck with it.

There is no way your tahoe will weigh anywhere near 7,000lbs with a duramax swap. Im really surprised yours weighs 6020lbs as it sits. Thats a couple hundred pounds more than a stock 1500 suburban. What heavy stuff do you have in it? Was that 6020lbs with you in the driver seat?

What are you going to do for a transmission/transfer case? Swap the allison and np263 in place of the 4L60 and borgwarner awd case?

I assume your tahoe is one of those oddballs with the "selectable awd + low range" transfer case and stabilitrak? They only had that setup for 1 year as far as I know...in 05 they went back to the normal autotrac case, even for the SUV's that also had stabilitrak. Stabilitrak will not work with the duramax ECM, so you will either have to swap to the older non-stabilitrak 3-channel ABS setup, or just deal with the "SERVICE STABILITY SYS" message in the driver info center.

With a little over 500rwhp duramax your tahoe should easily run mid/low 12's.

Duramax weighs 837lbs.

 

[turbhoe]

There is no way your tahoe will weigh anywhere near 7,000lbs with a duramax swap. Im really surprised yours weighs 6020lbs as it sits. Thats a couple hundred pounds more than a stock 1500 suburban. What heavy stuff do you have in it? Was that 6020lbs with you in the driver seat?

What are you going to do for a transmission/transfer case? Swap the allison and np263 in place of the 4L60 and borgwarner awd case?

I assume your tahoe is one of those oddballs with the "selectable awd + low range" transfer case and stabilitrak? They only had that setup for 1 year as far as I know...in 05 they went back to the normal autotrac case, even for the SUV's that also had stabilitrak. Stabilitrak will not work with the duramax ECM, so you will either have to swap to the older non-stabilitrak 3-channel ABS setup, or just deal with the "SERVICE STABILITY SYS" message in the driver info center.

With a little over 500rwhp duramax your tahoe should easily run mid/low 12's.

Duramax weighs 837lbs.

6020 was right after the run, with a tank of gas, me in the seat, single 12, nothing removed, and two kid seats. and i think some blankets and a stroller.

yes use the allison (built) and the 263 case along with parts from the donor so the service stability will go away. mine did have the borg warner 4482 (IIRC) case with selectable 4lo. but it sucks with its open differential and using the brakes to transfer power. so i pulled it and went with a np149 case. uses a viscous coupler and stronger. way better power transfer with this case. i like it a lot better as its more seamless.

 

[Chevy1925]

There is no way your tahoe will weigh anywhere near 7,000lbs with a duramax swap. Im really surprised yours weighs 6020lbs as it sits. Thats a couple hundred pounds more than a stock 1500 suburban. What heavy stuff do you have in it? Was that 6020lbs with you in the driver seat?

What are you going to do for a transmission/transfer case? Swap the allison and np263 in place of the 4L60 and borgwarner awd case?

I assume your tahoe is one of those oddballs with the "selectable awd + low range" transfer case and stabilitrak? They only had that setup for 1 year as far as I know...in 05 they went back to the normal autotrac case, even for the SUV's that also had stabilitrak. Stabilitrak will not work with the duramax ECM, so you will either have to swap to the older non-stabilitrak 3-channel ABS setup, or just deal with the "SERVICE STABILITY SYS" message in the driver info center.

With a little over 500rwhp duramax your tahoe should easily run mid/low 12's.

Duramax weighs 837lbs.

i dont think hes far off ben if he adds all the stuff to make the truck last like adding the build allison, 263 t-case and gettin rid of the 10 bolt rear for a 14 bolt or aam 11.5, the weight difference between all that would put you close to 600-800lbs over stock (guessing on the high end)

 

[turbhoe]

that's what i figure too. that trans has to weigh a good bit more than the 60e i have now. the 149 case doesn't weigh much at all so i'm sure the 263 weighs a little more. but iron block on iron block, i'm not sure how much more the dmax weighs over the 5.3L. and my intercooler vs the huge dmax one.

either way, i've done the most of my research on the swap itself and it seems pretty straight forward. like the 2" body lift. make a new cross member for the trans and move the motor mounts around a bit. then unplug all the wiring from both trucks and plug the dmax stuff into the tahoe. there are some other details in there as well but i'm now more curious on the strength of the eng. i mean to build a dmax is stupid expensive. i can build a full 5.3l stroker motor for the price of just forged pistons for a dmax.

 

[Colt]

Doesn[t the LBZ weigh about 890 lb.? The Alli isn't light either but it will take a beating in that front end if changed. Just how you have your tahoe is nice really seems like it would be easier to do a change on a truck frame with the right components already and avoid the work out on the tahoe. Just my look at it, the idea is cool but man you are in for some costs and headaches fitting it from other reading of even 1/2 ton subs guys changed out God they had a workout. I know not positive right? Just looking at the economics and labor to do it that's all if you do it go for it good to see the drive too.

 

[turbhoe]

well when they make a truck with a diesel that fits 6 without sitting 3 people up front ill do it. i have four kids and for long trips, 3 in the front is not comfy. the frame on the tahoe is different and has more bracing and a boxed from to keep the body from twisting around unlike a pickup where the bed and cab can move in opposite directions. so a truck frame tahoe isn't a very good idea. this is way cheaper than buying a new truck when you consider my tahoe is almost paid for.