Frank Ball wrote:
>
>
> Ok, so if a ported TBI isn't good for power at WOT, why should I buy
> one?
Judging from everyone else's experience and my personal observations I
think the ported TBI is not the way to go until the cam is changed and
whatever intake/head work you want is completed. Then match the throttle
body to the optimal cfm requirements of the "New" engine. If you want
one though, I'm sure you know someone who will be happy to sell you a
nice one ;-)
> Here's a more general question. We all know the intake and exhaust
> are
> the limiting factors in a stock Dak. Suppose a person makes the basic
>
> upgrades: D.T. Headers, 3" cat back exhaust, MOPAR computer, some big
>
> open element air filter, good plug wires. Ok now what's the limiting
> factor? What mod should be done next to feel an improvement? 3" high
>
> flow cat? The MOPAR cam and springs? A TBI? Something else? Then
> what
> makes sense after that? Low end torque is always nice, but top end
> is
> what I really need for passing. The goal is better top end with no
> loss
> in low end.
>
OK. Beleive it or not, I'm a fairly smart guy who proceeds with great
caution before modifying any stock engine due to limited cash flow and
years of previous experience building Mopar engines. Buying the
wrong/mismatched parts simply costs too much in time and money. Here's
what I recommend.
First: MP Computer
Second: Free up the exhaust in the following manner.
Replace the pipe at the manifolds with 2 1/4" aluminized carefully bent
by a skilled exhaust man. Connect this pipe into a 2 1/4x2 1/4x 3"
flowmaster aluminized Y pipe.
Next hook into a 3" high flow cat. Then all 3" into a Gibson cat back
system or you can have one custom made like I did with a 3" Flowmaster
Big Block muffler. In my opinion, the Doug Thorley headers are too
expensive and don't provide a significant gain over the factory
manifolds until you are really getting to serious horsepower levels. The
setup I have described will provide great gains and maintain much of
your low end torque. Oh yeah, have the shop mount your O2 sensor in the
Y pipe and downstream like the factory if you have a second one. This
total setup cost me less than $600 IF YOU DON'T GAIN AT LEAST 3-4 TENTHS
FROM THIS SETUP CALL ME AND I'LL SEND YOU FIFTY BUCKS!! And I don't
stand to profit a dime!
Third: FIPK/ open element air cleaner(or when your budget allows)
Fourth: Ignition system. I like my Jacobs Ultra Team but its pricey.
Jules tells me its no good, but its two years old and still working
great. I'm sure the MSD is also a good setup(I have seen a fellow
listmembers fail however) No manufacturer is perfect but the MSD is
cheaper.
Fourth: I did the underdrive pulley. They weren't expensive and got me a
tenth or so.
Fifth: Now its time to decide how serious a truck you want. Any further
steps will get you speed but start costing you bottom end. This is where
I am now. The cam/spring swap should yield the biggest gains here. If
budget allows have the heads ported and exhaust manifolds cleaned up(a
la Kukooters truck). Also, take a look at a possible intake
swap/modifications to take advantage of the new cam profile. This would
be the time to do a ported TB. If you can afford to do everything,
you'll be looking at around 380-400hp(Best guess)
Sixth: Now you can do the headers(if your bank account can stand it!)
I hope this helps. My advice comes from experience and observation. I
have nothing to sell you and don't stand to make a dime. Best of luck.
Now get busy and go corvette hunting!
Andre Mauboussin
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:48 EDT