neoboi

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.

HMT-Admin

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

neoboi

10 PSI HIGH? 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.

neoboi

o yeah all this on crappy 91 octain

HMT-Admin

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 *** and really only let you boost safely to 6-8psi.

Jeff

neoboi

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

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.

HMT-Admin

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

neoboi

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.

neoboi

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

HMT-Admin

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