bdeming

basically I have my LS1 from a 2000 z28 in a Nissan Silvia, and since the car is right hand drive my only real option for headers were the JBA "cat forward" GTO shorty's. my question is, about how far do you think I can push these headers HP wise? I have a TSP 228r cam, stock heads, injectors, intake/tb. I made a custom straight pipe 2.5in exhaust w/ xpipe. I would like to get more out of it but i don't want to waste the money if my headers are going to restrict me from making more power.

what do you guys have to say? I was thinking of doing an ls6 intake maybe a TB and different heads, any recommendations? thanks!

george g

iTrader: (12)

I had them on my ls1 with 243 heads and a professional products 85 mm intake with a 224/231 and made 410hp with them.I listened to everyone telling me I was leaving 15-20 hp on the table,so I switched to long tubes and the best my tuner could get was 5 hp. 410 shorties=415 lts

cali_bear2003

iTrader: (7)

George g

Did you see any noticeable gain in Torque? I too have the JBA's in a basically stock LS6 crate engine. I have been contemplating the 'LT' decision for a few years now, but just have not bitten the bullet for YOUR same reason.

Thanks...

jimmyblue

iTrader: (11)

I don't have numbers for you, but I have an anecdote.
The JBAs are not a significant restriction. I know this
because on a shakedown run after installing them,
Mufflex tubes and a 2-1/2" Y, I had an O2 sensor blow
out of the hole (which was marginally overtapped, but
still) in the Mufflex tube downstream of the header
collector. Saying that the headers were able to
pressurize the hell out of the pipe, not holding back.

What you will lose, likely, is midband torque. If you
are running an automatic and a higher stall speed
torque converter then this matters hardly at all,
you will slide right past where scavenging plays
and over to where it's all just about restriction.
And I say good shorties are no kind of restriction
relative to the long undercar plumbing-run and
the muffler.

Now there are good shorties, like JBAs, and there
are really shitty ones like you find on eBay from
fly-by-night sellers and no recognizable brand
name. I bought a pair because I was having a hard
time finding used JBAs. Worst design I've ever seen
for turbulence inducing steps at the outlet flanges,
"stainless" that rusted just like mild steel sitting
in the shed, thinner wall by far than JBAs and so on.