LS MAX BOOST?
 

ok my friend and i are building a turbo kit for an LS, most likly a T3 or a T3/T4 depends on our funds, my friend been into turbo since day one and tought me most of the stuff, but he doesn't know about honda motors, he build/race RX-7s (rotaries), he was wondering how much would a LS hold, with medium size core along with SAFC and 450CC injectors? we're just planning on 10-12 PSI no more than that, but since it's a open deck design and un-forged pistons we don't know about it.

Re:LS MAX BOOST?
 

Properly tuned, you can run 10-12psi on a LS block, (if its in good condition)

I highly recommend dyno tuning w/ a wideband o2 to get your air/fuel perfect, especially with that amount of boost.

You may also want to look into a spark device to back down the timing (I.E MSD BTM) running that much boost, you will need to back the timing down (per every psi)

JEf

Re:LS MAX BOOST?
 

10 PSI HIGH? :o :o shiat.

well ok i guess, how about an FMU setup with a MSD ignition setup? how much psi can the LS handle without blowing?

thanks.

Re:LS MAX BOOST?
 

o yeah all this on crappy 91 octain

Re:LS MAX BOOST?
 

Well you asked the max? It probably could even go higher, I have spiked my ls/vtec around 13 a few times, no problems. (but I do have great fuel management)

How much with a FMU/MSD BTM setup, not alot, FMu's blow ass and really only let you boost safely to 6-8psi.

Jeff

Re:LS MAX BOOST?
 

i meant 10 PSI as is THAT'S HELLA LOW! SHIAT! :o :o

so what's your setup AbaZ? is it the 60-1 in the CRX? i'll prolly let it stay at 8 PSI, with the MSD ignition and FMU for now, or maybe without the MSD ignition because it's only useful for around 9+ PSI right? damn so much to learn for HONDAs.

I'll prolly give the kit 7.5 PSI. O yeah is it possible to retard the timing with the dist method? we're not very use to distrubutors also, too use to coil/CAS setup from the RX-7. I just need this kit to run right and long and atleast over 5.5 PSI.

Re:LS MAX BOOST?
 

You need to understand 10psi on a LS is a bit different than it is on a RX7.. Honda's respond very well to 5-8psi. Where it normally takes Factory boosted cars 10-20psi to make some good power. 10psi on stock internals is pretty decent, B/D series have open Decks, and use cast pistons, which are very prone to break with any type of detonation. B-series rods are pretty decently sized and can take a fair amount of HP.

Move the distributor back? Ya you can, but then you would be sacrificing your bottom end, thats kinda the idea of a BTM, it backs your timing while your boosting, so you dont loose anything at the bottom end.

I'm serious, FMU's are ------- shitty, especially in conjuction with the stock 240cc injectors, people can easily run lean with these setups, and damage the stock injectors. Your better off with a AFC type hack (using larger injectors)

60-1 T4 in the Race Car (built ZC), and T3/T4 .48ar ex .54comp in my daily driver (stock LS/Vtec).

Jeff

Re:LS MAX BOOST?
 

i see, how much would it to be (to the gound) horsepower?

do you think

AFC hack and 450cc, and some retard timming from the dist. lean out much on no-boost to gain a few horses and then richin as boost flows,

is a good idea for 8 psi setup?

i already know about the open deck design, that's why i was scared boosting a honda/acura, many later on in this LS motor life it can get some iron sleeves.

and

stock turbo is fairly small for an RX-7 that's why it takes somemore boost to get some HP, stock turbo RX-7 is about large T03/small T4 and isn't efficient for stock ports, with my friends set-up T04E 60-1, he is using about 14 PSI on pump of "great" california 91 octain gas for his street setup and has about 330@rear wheels.

Re:LS MAX BOOST?
 

and not to talk ---- or anything, but ur icon is scary.

Re:LS MAX BOOST?
 

afc hack with some 450's running 8psi is fine, as long as its tunned good.

Factory RX7 turbos are not that small at all, I was looking at one the other day, the exhaust wheel is fairly large.

How much HP? their are tons of factor's, but I will give you a rough idea..

boost ls should be from 180-250 to the ground

Jeff