hondarider2289

Looking to build a turbo motor for my rear engine mud truck, I've been researching this for a while now and was looking to have a few questions answered for me since my application is a little different then everyone elses on here.

I already have a L33 5.3 with the 799 heads, Th400, microsquirt and harness, A1000 fuel pump.

I was looking to put either twin on3 70mms, or a single on3 78/75 setup on this, and keep the motor stock except for PAC 1218 valve springs, and maybe a cam if i need it to get to my power goals.

I'm shooting for over 800hp at the crank, the main thing I'm worried about is turbo spool time, don't want it to be laggy.





Truck its going in is a tube chassis, rear engine, 4 linked, tractor tires, military 2.5 ton axles, that weighs in at around 5100lbs



My main question is in a truck this big and this heavy will that affect my turbo sizing any?

hondarider2289

Tire size is 49", axle ratio is 6.72, and have either 1:1 or 2:1 in the transfer case

66Chevellelq4

im no expert but with a truck that heavy and tires that huge the engine will be under an enormous load so i dont think spooling a turbo on the larger side would be an issue. I think the 78/75 might even be a little small for that application

hondarider2289

Yea that's also what I was thinking, and packaging isn't an issue because I have the entire bed area to work with.

hondarider2289

Anybody else have any help? considering the on3 88mm now....not sure if it'll be to much or not

TrickPerformanceProducts

iTrader: (11)

You want 800 at the crank
With that heavy truck cost would say twin 70s.
68 on the exhaust side.

hellbents10

iTrader: (10)

I have a customer with a 370 and a single 75 BW and he loves it. It has the 87mm turbine and t4 1.25ar housing.

Rob383

If you want jump out of the hole power, i would say twins. Looks like a fun mud truck. My friend has a ford with 2.5ton's 6.0chevy with box 475bw turbo. It moves out pretty good. Good luck with your mud truck.

pun young

6.0 with a s475
14.9s 2.5ton turbo 400 and 2to1 in the case
word of advise make sure everything is water tight, my injectors didnt sit right in the intake because fuel rail was off, and killed my motor

suicidal racing

iTrader: (14)

the pit viper was either a 5.3 or 6.0 with a s475 couple yrs ago..heres a vid of their new setup

hondarider2289

yea i watched your build over on tgw pun, loved the way it turned out

hondarider2289

Also saw the pit viper, that thing is nasty, made me consider the 88mm on3, just don't know if I'll be able to spool it or not

Fat Jesus 808

iTrader: (5)

S472 or S475

suicidal racing

iTrader: (14)

im not sure on the exh wheel on the on3 88mm but remember this you can play with the cam valve events if your looking to spool a big wheel or you can shrink the hot side so instead of a 2.25 use a 2" to get it to spool sooner,use a twin scroll deal and keep the tubes sep and lead them up into the housing its self..your not in a all out drag class where you will be seeing high rpms and living up in that area 90% of the time so some back pressure wont kill you if you use a smaller hot side.

suicidal racing

iTrader: (14)

bad *** truck got a link to the build? ive wanted to do a mud truck for yrs,,since i left florida where i live now it wouldnt be much good..its all more trail rigs up here in mass.

pun young

here the link to the motor build on here and have the whole build on another forum

https://ls1tech.com/forums/forced-in...noise-vid.html