Help me spec twins
Help me spec twins Im thinking about selling my 72 turbo camaro and picking up a 78-81 el camino as my main ride. I plan to stick a l33 5.3 in the camino and probably back it up with a 4l80e . Im gonna look around and see if i can find an 8.5 10 bolt to replace the 7.5 the el camino comes with too. Plan is to put a set of ported 243s on it and stick a mild turbo cam in it. I want to run a pair of turboes sized to come in pretty quickly, but still spin the l33 to 6500 and not choke it down too bad on the turbine side. I plan to run on the wastegates springs in day to day driving and have my boost controller set on kill at the push of a button .
id be lying if i said it wont see some 1/4 mile action, but the main use would be a fun street car that handles decent , stops good, and can haul trash off or pick up a hand full of 2x4s if i need them.
im not going to have a huge budget, so i will be looking at VSracing or borg warner turbos.
I have a pretty good handle on singles sizing, but not very confident with my judgement on small twins on a 5.3.
id be lying if i said it wont see some 1/4 mile action, but the main use would be a fun street car that handles decent , stops good, and can haul trash off or pick up a hand full of 2x4s if i need them.
im not going to have a huge budget, so i will be looking at VSracing or borg warner turbos.
I have a pretty good handle on singles sizing, but not very confident with my judgement on small twins on a 5.3.
TECH Regular
Joined: Jul 2019
Posts: 460
Likes: 44
I have 2 eBay gt35s on my 5.3 with 706 heads and all btr head gear. Btr stage 2 cam. Block is .30 over but off brand pistons and stock rods.
http://vi.raptor.ebaydesc.com/ws/eBa...=0&cspheader=1
i put it on dyno few weeks ago before tune to see if everything held together and spool was quick... hit 6psi by 3600rpms BUT it looked like power was dropping off around 5900 rpms. This was with richer than 10.0 air fuel and 9* timing across whole map. Hopefully when tuned it changes but for now it seems like I should’ve gotten alittle bigger hot side.
http://vi.raptor.ebaydesc.com/ws/eBa...=0&cspheader=1
i put it on dyno few weeks ago before tune to see if everything held together and spool was quick... hit 6psi by 3600rpms BUT it looked like power was dropping off around 5900 rpms. This was with richer than 10.0 air fuel and 9* timing across whole map. Hopefully when tuned it changes but for now it seems like I should’ve gotten alittle bigger hot side.
So a 62mm t4 exhaust is too small ? Im glad i started this thread cause i would have thought that would have been enough wheel for a 2.65 liter 4 cylinder at 6500 rpms. Maybe i should be looking at something in the 68mm exducer turbine in a t4, or better yet, a v band exhaust flange. Thanks for the responce.
TECH Fanatic
Joined: Sep 2013
Posts: 1,008
Likes: 126
From: Mechanicsburg, PA
ls1tech.com/forums/forced-induction/1797340-i-am-having-twins.html
ls1tech.com/forums/forced-induction/1816407-twin-turbo-33-pickup.html
Couple good reads there. Tom's car was drag race only but ran very well and spooled quickly.
ls1tech.com/forums/forced-induction/1816407-twin-turbo-33-pickup.html
Couple good reads there. Tom's car was drag race only but ran very well and spooled quickly.
TECH Regular
Joined: Jul 2019
Posts: 460
Likes: 44
So a 62mm t4 exhaust is too small ? Im glad i started this thread cause i would have thought that would have been enough wheel for a 2.65 liter 4 cylinder at 6500 rpms. Maybe i should be looking at something in the 68mm exducer turbine in a t4, or better yet, a v band exhaust flange. Thanks for the responce.
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
So a 62mm t4 exhaust is too small ? Im glad i started this thread cause i would have thought that would have been enough wheel for a 2.65 liter 4 cylinder at 6500 rpms. Maybe i should be looking at something in the 68mm exducer turbine in a t4, or better yet, a v band exhaust flange. Thanks for the responce.
TECH Enthusiast
Joined: Dec 2017
Posts: 676
Likes: 72
these exact turbos were used in 2 other threads on this site. One made 748whp on them. That’s why I purchased them. I’m not sure why they run out of steam so soon for me. I’m really hoping tune clears it up but afew people were at dyno that day and told me the hotside was just too small.
Trending Topics
TECH Regular
Joined: Jul 2019
Posts: 460
Likes: 44
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
No kidding. People try to stay safe, but that is ridiculous. At that AFR and timing nothing will make power.
TECH Regular
Joined: Jul 2019
Posts: 460
Likes: 44
it was just a generic basemap for me to put some miles on clutch and test out swap. I’m excited for what it does when my tuner actually touches it.