Go FaSSt Basics
Here's a list of basic
recommendations for making a b-body faster.
The important thing to remember is that our cars are old and
somewhat unique compared to the usual Camaro and Vette. Our cars
are heavy and have an LT1.
With that in mind, talk to the guys here on the forum or a local
B-body club who have the real experience about what works and does
not. They're out there.
You just have to be willing to listen.
With a cold air induction system, valve springs, 1.6 roller
rockers, headers, cat back, TC, gears and tune you can have a very
good performing B-body. Heads & cam
and/or 383's are not required to have a fast & fun B-body.
Note that the list is not in a particular order except for the
1. First: Educate yourself about your LT1 engine:
2. Decide: Set a performance goal and budget and stick with
it. Research and research more. Talk to local B-Body club members
about your goals. Search this Forum.
Compare setups, engines, cams and heads here:http://www.top-et.com/impalass/
3. Tune up: Make sure all the basic tune up stuff is done
and start with some "free" mods like the throttle body bypass.
Here are two good sources for "basic" information about our cars,
the LT1, maintenance and modifications:
4. Induction: Help your engine breath with a do it yourself
"Home Depot" & "swiss cheese stock air box" system or spend the
extra money for a nice RAISS system. Note that the performance
gains are very small between the do it your self system and the
high end RAISS. Here is a list of induction options:
5. Exhaust: Help your engine exhale with headers and cat
back exhaust. List of header & exhaust options:
Tri-Y headers are a great performance mod for a stock and heads &
cam 350. There are several "cat back" exhaust systems offered. Go
with 2.5 inch diameter pipes for a stock to moderately modified
LT1. A good budget exhaust option is to replace the stock mufflers
and leave the stock resonators on.
6. Valve springs and rockers:They will maximize your stock
cam potential and give you higher RPM performance. There are a few
after market valve spring kits but Comp Bee Hives seem to be the
#1 choice. Go with a 1.6 roller rockers. Comp Pro Magnum self
aligning 1.6 roller rockers are the #1 choice. Note that
aftermarket cams require valve springs and roller rockers that
maximize their lift. The cam manufacturer will specify the correct
springs and rockers for their cam. See #9.
7. Torque converter: I would invest in a quality TC. Yank
is a top choice by many. I do not recommend higher than a 3000
stall on a stock engine. With a 350 heads & cam, 355 and 383
engine you can go much higher than 3000. I recommend adding a HD
finned trans cooler for the life of your TC and trans.
8. Gears: For a street/track combo, go with 3.73 gears.
They are fine on the street, highway and perform well at the
track. When you do your gears it is a great opportunity to replace
your stock Posi with a HD one from Torsen, Auburn or Eaton.
9. Heads: Ai
and Mike Harris are some of your top choices for LT1 head porters.
Dan Fahey is good a option for iron heads. Commercial "off the
shelf" or "out of the box" heads can be expensive and not perform
as well as having your stock heads worked over by a good porter.
If you have money, you can purchase new heads from Trick Flo, Dart
or AFR and have Ai, LE or Mike port them.
10. Cams: If you go with Ai or LE for your heads it is best
to have them recommend a cam that will match the heads they built
for you. For stock LT1 engines, the Crane 227 & GM 845 are great
off the shelf cams. There are many other cam options, but with out
a doubt the 845 & 227 have consistently proven to be performers
for our cars. The GM LT4 Hot cam will need more stall and gears to
be maximized. The GM LT4 Hot heads & cam kit was a great setup
originally designed for Corvettes with 6 speeds. It was the only
option for us a long time ago. There have been many better head &
cam options offered since the LT4 Hot cam kit.
11. Strokers: This is where things can get very expensive
IF you want this done correctly the first time. You do not
want to cheap out here. Quality rotating assembly and heads & cam
specified to take advantage of the extra cubes AND a
quality LT1 engine builder are paramount to a successful build.
Stock heads or some commercial "off the shelf" heads on top of a
383 will not maximize the potential of the stroker.
12. Engine Builder: "There are good parts and there are
good motors, don't confuse the two." Mr. Mike Harris. If you
can not do the engine build yourself, this is another area that is
critical with going with experience and quality. The LT1 is
different than a normal Chevy Small Block in some areas. You want
a builder who knows the difference. My #1 recommendation is Karl
Ellwein or Mike Harris. Check out Karl's list of quality builds:
http://www.ellweinengines.com/ If you
decide to cut corners be prepared for poor performance and
quality. You will spend more money in the long run because the
engine you were in such a hurry to have now is slow and/or blows
up. There are plenty of stories where builders have taken customer
parts to build them a dream engine to only find out that all their
parts they gave to the builder are not in their dream engine.
13. Programming: This is one of the most critical
modifications. Not done correctly could cost you a engine and/or
trans. You need an experience programmer who knows LT1s. I have
used PCMForless. Other options are PCMPerformance & Ed Wright. The
HyperTech programmer is only good for clearing CELs and gears &
wheel size adjustments. Tuning with a 160 degree stat and CIA will
make a stock car perform very well. Get a LT4 knock module for
14. Intake, throttle body, fuel and MAF sensor. The stock
intake is fine. If you go with heads & cam and a stroker have Ai
or LE port your stock intake. Go with a 58 mm throttle body if you
are going to add heads & cam. If you are not going with high
performance heads & cam, a 52mm TB will do. The only MAF you need
is an GM F-body one. You'll need larger injectors for built LT1s.
30lbs minimum. HD fuel pump. Check this out:
The stock fuel regulator is good.
15. Weight Reduction: Things to lighten the weight of our
heavy cars: lite 15" wheels, headers, cat delete, tubular trans
cross member, aluminum bumper supports, remove front sway bar and
add a HD aluminum drive shaft. There are many other little things
that add up like removal of the air pump system. You have to
decide how far you want to go like living without AC.
16. Transmissions: 6 speed manual kits are available. As
for the stock trans, it's eventually going to give it up when you
add more TQ. When you go with your heads & cam or stroker be
prepared to invest in a built 4L60E. There are good built 4L60Es
surviving in some very quick cars with lots of good aftermarket
parts available, so find out who built that trans and then use
him. Also, do not be afraid to start building them yourself but
there is a learning curve. Check out CPT:
http://www.cpt4l60-e.com/ & ProBuilt:
http://www.700r4l60e.com/. For local
options, ask B-body owners in your local clubs.
17. Brakes and suspension: Now that your ride is fast it
would be wise to upgrade your brakes & suspension. Go here for
Do the Proportioning and Metering bolt mods if you have 4 wheel
disc brakes. Bilstein sport shocks are great if you want a firmer
ride. Coil lowering springs can be a personal preference. Vogtland,
Hotchkis and Eibach are good decisions. Do the lower body
bushings. Some lower body bushings were not installed at the
factory. Upgrade your rear lower control arms. Suspension options:
You can get "extended" rear control arms to center the rear
wheels. Do not go with solid rear upper control
arms. You risk cracking the frame at the upper CA mounting
location because the solid arms do not flex and/or twist. For sway
bars look at Hotchkis, BMR, HA and HO.
18. Hooking: With all of your new extra HP & TQ, you're
going to need some drag radials or slicks to hook. I recommend
going with slicks on some lightweight wheels.
Not only will this help your times, your back will thank you when
you unload them from your trunk. Tracks require a drive shaft
Safety Loop if you use slicks.
There are many other little things like electric water pumps and
plugs. I am just providing basic recommendations. These are not
the only choices and may not
be the best option for your goals.
There are many other ways to go faster. I did not cover power
adders and nitrous because I do not have any experience with them.
This thread is here to give
you a basic foundation to start with. PM the guys who have the #'s
to back their advice. Go to local club meets. Join the clubs and
race series like ECIRS.