LSx Turbo setups

[Verz]

Im looking to do a LSx turbo in my 85 monte and have a line on a 4.8 for cheap. So everybody post up your setups with pics and mod list.

[ITSNOTAGN]

how cheap is cheap? I would go ahead and buy it for sure if its cheap as im thinking. Look for my posts on this forum it contains alot of details.
Gary

[Verz]

Originally Posted by ITSNOTAGN

how cheap is cheap? I would go ahead and buy it for sure if its cheap as im thinking. Look for my posts on this forum it contains alot of details.
Gary

Cheap is $600 for a 02 4.8 with 19k. Planned on a twins setup with some small turbos from say a srt4 or eclipse. How cheap were you thinking and if you have one in mind i wouldnt mind a link. Thanks im searching through your posts now.

Also I can get a 03 5.3 with 47k for $800 would that be a wiser choice?

[ITSNOTAGN]

both of those sound very good. The only difference between them is the crank, and i always wanted to do a 4.8, then swap to a 6.0L block and use the short stroke crank, spin it to 7500, it would be sick. Whatever one is more complete would be the better one, same, id go 4.8, but thats just me.
Gary

[Verz]

Originally Posted by ITSNOTAGN

both of those sound very good. The only difference between them is the crank, and i always wanted to do a 4.8, then swap to a 6.0L block and use the short stroke crank, spin it to 7500, it would be sick. Whatever one is more complete would be the better one, same, id go 4.8, but thats just me.
Gary

A guy on ls1 tech had just recommended that idea to me and i wasnt sure how it would work out.

4.8l truck motor-High revver? - LS1TECH

This was the questions I had

Sounds like a good idea but have a few concerns. I know the 6.0 pistons weigh quite a bit more than the 4.8 pistons(believe 24 grams) so wouldnt that throw off the balance of the crank? Also from what ive read the Lq4 and lq9 both have 71cc heads, what changes the compression ratio? and if i used say the lq9 pistons what chamber size would i need to drop the compression into a boost friendly zone? Also what advantage would this have over just boosting a 5.3?

Well i did some research and found the longer rod would have increased piston dwell and be more effiencent and rev faster in the upper rpms so that answers the last question. Im sure i can probably get some pistons made that would work with that setup but woud there be a cheaper way if i used the lq4 pistons?

[ITSNOTAGN]

well if your going through the trouble of tearing into the motor, your gonna need pistons and rods anyway. The 4.8 and 5.3 use the same pistons, and the extra stroke was taken up with rod length. The pin heights on all LSx pistons are the same so its just a matter of finding a set of aftermarket 6.278" rods to make it work.
I put this in dyno sim and a stock 4.8, with a single plane intake, carb, and 03 ZO6 cam and 9.4:1 compression makes 440hp at 6500rpm, and 386lb-ft at 5000. Only changing the bore from the 3.779" (293 cu in) to 4.03" (334 cu in) hp is the same 440hp at 6500, but 418lb-ft at 4500 rpm. As reference, going to a 6.0L, 3.625" stroke yields 423hp@5500, and 428ft-lbs at 5000. I seriously would love to do this, and with that your rod ratio goes to 1.92, which is rediculous. Stock 6.0 rod ratio is 1.69. That is a large difference in piston speed.
Gary

[Verz]

From what ive read the 5.3 uses a dished piston instead of a 4.8 flat top so it can keep compression down. Also my impression was that the rods would be fine just the rod bolts would need to replaced with something better.

The numbers do look good and the increased power and rpm range over a regular 6.0 seems to justify the build. Thanks for hte help

Also I noticed you were selling the 87, any interest in selling the log type manifold and downpipe?

[topher455]

Keep in mind you dont want a motor with super low miles. The ring packs are pretty tight on these motors and you run the risk of ring butting under boost. I would say go for the 5.3 like they say theres no replacement for displacement except boost. So why not have both??!!!!

[Verz]

Originally Posted by topher455

Keep in mind you dont want a motor with super low miles. The ring packs are pretty tight on these motors and you run the risk of ring butting under boost. I would say go for the 5.3 like they say theres no replacement for displacement except boost. So why not have both??!!!!

This is true, ive find quite a few deals on 5.3 so ill probably end up getting one unless a 6.0 comes along

[Chuck Leeper]

"a stock 4.8, with a single plane intake, carb, and 03 ZO6 cam and 9.4:1 compression makes 440hp at 6500rpm, and 386lb-ft at 5000." Huh???

[ITSNOTAGN]

Is there a problem?? i thought that was a pretty straight forward combination?
Gary

[Chuck Leeper]

A 4.8, [<300CI] displacement, a 9+ cr, a mild cam and a 4 bbl, takes an engine that's rated at less than 300FWHP, to 440HP???
The combo may be "straight forward", but the results are what strikes me as a bit optimistic.. that's all.

[ITSNOTAGN]

granted its an optimised combo, but i was simply using it as a comparison. Aside from that a 4.8 run without accesories and a really good tune on 93 octand can put down 310hp, and the cams in these motors are only good to 5400, so giving it a cam that allows it to rev to 6500 it will pick up considerable power.
Gary

[topher455]

There is huge power to be made with a cam swap in these ls motors because for the most part they all got the same or very similar camshafts as a result of GM parts sharing. Also keep in mind these are roller cam motors with 18 degree cathedral port cylinder heads. Not your typical sbc. All the really cool stuff is there so putting in a cam is kinda like turning on a light switch. Six bolt mains and a deep skirt block dont hurt either. The power estimate may be somewhat optimistic but it really doesnt take much to make these motors fly. Most heads cam intake guys on ls1 tech are putting down about 450-480 with a good tune and a couple have passed 500. Btw horsepower measured at the wheels.

[Wes 88 SS]

complete turbo kit, sheetmetal intake for sale. - LS1TECH

[Verz]

Originally Posted by Wes 87 Turbo T

complete turbo kit, sheetmetal intake for sale. - LS1TECH

That thing is huge. How would a pair of mitsu TE04 turbos perform on a 4.8/5.3 running say 12-14psi? I would expect the them to spool pretty quick and make power to atleast 6k, any idea.

[ITSNOTAGN]

LOL, those would basically spool at idle and be out of breath around 4500, that is way way too small for even a 4.8. Now a pair of 50-trims would be okay, but i would prefer a 60 trim/stage 3or 5 wheel for twins as they would take you to -700whp it you wanted.
Gary

[Verz]

Originally Posted by ITSNOTAGN

LOL, those would basically spool at idle and be out of breath around 4500, that is way way too small for even a 4.8. Now a pair of 50-trims would be okay, but i would prefer a 60 trim/stage 3or 5 wheel for twins as they would take you to -700whp it you wanted.
Gary

Guess i was misinformed but did do some reasearch and realized they are too small. Im only looking ot make around 400rwhp with a cam and the turbo/s.

What about a pair of Garrett TB0363 turbos? This is all the info I found on them
-Model: Garrett/Airesearch TB0363 (T3 Series)
-OE Part #: 466672-2
-Wastegate setting: ~7 psi
-Compressor Trim: 50
-Turbine Trim: 69
-Compressor Housing a/r: .42
-Turbine Housing a/r: .48
-Oil and Water Cooled

If not what is a good pair of small turbos, that will spool quick and make good power up to about 6600 or so.

[ITSNOTAGN]

you can make 400whp with nothing but a small cam and go wver the heads yourself, why would you want to mess with turbos. I wouldnt even consider it unless you want to make 450+whp. Hell i make 400whp on like 2psi, so it would be pretty much retarded. Buy some headers and mounts and put it in.
BTW if you want twins, get 2 stock GN turbos, they are perfect for spool up and will make 600whp.
Gary

[Verz]

Originally Posted by ITSNOTAGN

you can make 400whp with nothing but a small cam and go wver the heads yourself, why would you want to mess with turbos. I wouldnt even consider it unless you want to make 450+whp. Hell i make 400whp on like 2psi, so it would be pretty much retarded. Buy some headers and mounts and put it in.
BTW if you want twins, get 2 stock GN turbos, they are perfect for spool up and will make 600whp.
Gary

Well ive driven NA and supercharged cars so I wanted to see what the turbo side has to offer. I could always go for more power then my 400 but thats my mininum, I just want to go as fast as I can without having to put all the safety equipment in (i.e. roll bar/cage, driveshaft loop etc). Twins or single doesnt matter, just always seen smaller turbos paired together for cheaper.