turbotater

went to the dyno today and played for a while
i started at 292rwhp 343 rwtq with what i had tuned on
the street and ran 13.14 @105 last friday .. the a/f
was mid 11's in the lower rpms leaning to low 13's
at 4600 and then went back to mid 11's after 5000 ..
leaning it out down low picked up 25 rwtq at lower
revs tapering off to a gain of 15rwtq at higher revs ..
horsepower gains increased about 15 down low to
10 as it revved up .. my a/f is still not flat , at 4600
to 5000 it starts leaning out a little to 13.4 and then
falls to 12.1 by 5500 ... i would flatten it out but it
would loose power every time . i tried moving timing
(32 degrees worked best ) .. not sure what the problem is
i will post a graph tommorow ..

i also tuned a 90 vette with a converted carb intake
manifold - 219 cam - headers - ported heads - etc
made 332 rwhp and 343 rwtq ... it has gone 12.13 @112
with a super ram intake at 325 rwhp and 361 rwtq
it has a lot more rpm range now .. we will find out how
both cars run this friday ..
later

poncho@home

I notice in your sog you have 4 oval shapped intake runners...in other words fully siamesed runners...did you notice any differences with this? Any gains or losses?

I am thinking of doing this exact thing but are interested in your experience.

turbotater

i did h/c/i at the same time hard to say ...
i thnk it is better than stock runners and
a siamesed base .. some thing is holding me back ,
i am hoping to try a different throttle body
to see if that is the problem or if the intake is


i was going to post a current pic but i can't
get it less than 132kb in size anyone want
to host it?

turbotater

here is a copy of the graph

1989GTATransAm

iTrader: (3)

Was that dyno run with the stock firebird aircleaner or no aircleaner? If so it needs to be upgraded. Preferably with a K&N of a larger size.

Trying to figure out your exhaust system. If you still have the stock "Y" pipe you are loosing 10 to 15 HP if not more. You need a 2 1/2" pipe from the headers to the cats. Hopefully you have two or at least a 3" cat if single. Also 3" to the muffler and a good flowing muffler.

Bottom line is you need a good free flowing intake system and a good flowing exhaust system. Otherwise you are leaving horsepower on the table. I'am assuming you have a speed density system. Allen

turbotater

i have a 9 inch cone k/n on a 3 1/2 inch diameter
air intake and slp uses 2 1/4 inch from the headers
to form the y pipe then i have a 3 inch exhaust cutout
that i had open .. most people have an underdrive pulley
that i don't that might be worth 8-10 hp ,most folks
have a 9 1/2" or 10" torque converter that might be worth
a few hp ( besides some better launches ) due to less
mass .. at least this is my guess to why it make less than
some other combos ..
what hurts me most right now i think is my peak torque
area is 3700-4500 and peak power 4500-5000 which
is a narrow power band .