More horsepower and torque?!

[Blue95]

IT is not worth your time to give to him.

 

[Tempted]

Because I had just came from another thread about a 383 crate motor in an OBDII truck. I skipped the first post and didn't see what year the truck was.

Regardless, a TBI spacer isn't going to do anything. An isolator will but again I don't know if they make one for us. Since most of the TBI trucks run rich enough to power a Honda Civic on our exhaust fumes increasing the pressure is only going to waste gas and reduce power. If the engine is popping out at top end then it might could use a little more fuel pressure to counter the drop of long, heavy throttle runs. But again, just increasing the amount of fuel absolutely, 100% doesn't increase power. Fuel is only the accelerant, without air the engine can't perform. Jam twice the fuel in and get half the power. In order to get power from the increase in fuel you need an increase in air. And a TB spacer does not assist in fuel atomization. Once the charge is pulled into the hot combustion chamber the charge will instantly atomize. Heat and fuel are like Mentos and Diet Coke. Alone they are stable but put them together and they instantly release energy by de-gassing(I think is the right term).

 

[Blue95]

Because I had just came from another thread about a 383 crate motor in an OBDII truck. I skipped the first post and didn't see what year the truck was.

Regardless, a TBI spacer isn't going to do anything. An isolator will but again I don't know if they make one for us. Since most of the TBI trucks run rich enough to power a Honda Civic on our exhaust fumes increasing the pressure is only going to waste gas and reduce power. If the engine is popping out at top end then it might could use a little more fuel pressure to counter the drop of long, heavy throttle runs. But again, just increasing the amount of fuel absolutely, 100% doesn't increase power. Fuel is only the accelerant, without air the engine can't perform. Jam twice the fuel in and get half the power. In order to get power from the increase in fuel you need an increase in air. And a TB spacer does not assist in fuel atomization. Once the charge is pulled into the hot combustion chamber the charge will instantly atomize. Heat and fuel are like Mentos and Diet Coke. Alone they are stable but put them together and they instantly release energy by de-gassing(I think is the right term).

You crack me up. So a isolator that is say an inch tall will help, but a TB spacer that is an inch tall won't help? 1 or 2 psi does not mean twice the fuel. that extra area will help the fuel and air atomize before it enters the chambers which helps just as a spacer on a carb setup or a single plane intake on either setup.

Still wrong.

 

[DRAGGIN95]

Thottle body spacer's do work on TBI motor's as well as carbed SBC's because they increase the plenum volume from the point where the fuel and air is being injected or sprayed. I will agree they do nothing on a multiport efi setup like a vortec though.

 

[woody80z28]

Please explain how he would tune his stock ECM with out expensive PROM writers, and a program to alter the fuel and spark tables.

Yes the stock '88 to '95 blocks are roller compatible, he will also have to add a cam thrust bearing in the timing cover or a cam plate. This is because with a roller can you loose the built in rearward thrust that the cam lobe profile gives you to ensure the cam is always in contact with the distributor gear.

PROM writers are cheap. You can get a BURN1 from Moates for like $60, and the chips are $5/ea. I got an Autoprom for $200 that does everything: read/write/burn/erase/datalog. The TunerProRT software I use is free, and there are definitions available everywhere. I took the stock $0D 7427 tune and modified it for my setup pretty easily. Fuel/spark and 100 other variables that are editable within a stock BIN file.

I know the roller cam needs a cam plate, that's why I mentioned it in my thread earlier. The timing set I linked includes it and the bolts.

Actually there have been many independent tests that show TBI spacers only help out in the upper RPM's where our engines rarely spend any time. Also they have been shown to be very application specific and do not always help out. And he is right about the higher fuel pressures not doing anything unless you tune the computer for the higher pressures. More over in order to get the most out of fuel pressure increases is to use a Vacuum Referenced Fuel Pressure Regulator. This regulates the fuel pressure based on how much vacuum is being drawn by the engine. The lower the vacuum, the more fuel it lets through. Higher vacuum requires less fuel. This has to do with the amount of fuel that drops out of suspension. At lower vacuum times, more fuel collects on the walls and port floor of the intake runners. Fuel burns best when it is well atomized.

There are tables for accel enrichment and decel enleanment for the fuel that coats the walls on accel and then is sucked off the walls on decel. You can adjust these to compensate for the vacuum differences.

Have links to your TBI spacer tests? More plenum volume and full length headers both help low end torque from everything I've ever seen. If you make your exhaust pipes too big then it will hurt, but correctly sized pipes for best velocity will help and not hurt.

 

[The big beast!]

Wow! Thanks for all the info guys! But I'm a little lots now haha, I'm now thinking about a new can and set of heads but I don't know anything about the computers! :/ so what would I need to update the computer for new heads and a cam? Is there anywhere I can get it done?! Sorry I'm kind of a newbe when it comes to computers.

 

[Blue95]

So, like I stated why don't you start with the simple mods? and see how you like it.

 

[beast94]

I have used both TunerPro and TunerProRT and it is very good IMO for free software. The only thing a spacer does is increase plenum volume. It has nothing to do with fuel and fuel atomization. All it gives the engine is more air beneath the TB to draw from. Stock fuel pressure ranges from 9-13psi (normally between 11-13) on our trucks so unless your running more than that or using larger injctors, its not doing you any good. Please read the links below about TB spacers...

http://forum.grumpysperformance.com/viewtopic.php?f=55&t=1038

http://bb.bc4x4.com/showthread.php?7163-Throttle-Body-Spacer...Does-it-REALLY-Work

http://www.tundratalk.net/forums/tu...tions/102297-throttle-body-spacer-yes-no.html

http://www.f150online.com/forums/2004-2008-f-150/310797-throttle-body-spacer-tests.html

 

[beast94]

We are not saying that you do not have valid things to offer. We are just saying there are better ways to go about things.

 

[1997chevydriver]

All of your examples are on "dry" intake systems