I want to know what I should do to make my TBI motor go a bit faster. Budget is an issue but so is speed. Here is a current list of mods:

Edelbrock TES headers
Slp 3" catback
TBI spacer
180 degree thermo
Homemade raim air w/ K&N filter
Rapid fire plugs
MSD wires
Accel cap and rotor
And various suspenion mods.

Thanks

Aaron

 

3.73s and a SLP take out posi.

 

How hard is that? How would my gas milage be effected?

 

You should get it done by a shop. Your gas mileage will suffer a couple mpg most likely, but if you do mostly city driving it is not a problem at all.

 

Gears/posi. I say 3.73s. It's an expensive mod, but you will be glad you did it. I know I was. City mpg won't be affected, although highway might be affected slightly.

 

definately 3.73 gears and posi, and if you dont have the money for it now, save!!!!!

 

When you say expensinve what are we talking?

 

About $150- 200 for gears and another $300-400 for a good posi.

 

I got 3:42's and I cruise at 1950 rpm at 55 mph with a 700r4. What are you guys turning at 55 mph with 3:73's and auto trans?
Thanks, Dave

 

im sure so of you know about this, but for those that dont:
http://www.f-body.org/gears/
i find it to read low, probably because it is all mathematical w/o any "losses" (i.e. TC slippage).

 

If it was me, since we're not making much power with these cars, I'd just get a set of good low mile used 3.73s (check Camaroz28.com 's classifieds, they're on there for $99) and then the SLP take out posi for $99. Id bank on $200ish for the install.

 

How about adding an edelbrock intake manifold and an ijector spacer? What kind of power increase would I see from this? Is MPG effected?

Thanks

 

imo the intake manifold isnt worth it unless you have heads and/or a cam. The stock heads and cam dont require the extra air/fuel a better manifold provides. I mean you'll pick up a little, but in your situation Id get gears.

 

I wass just thinking the extra intake might worknicley with the opened up exhaust.

 

gears $200, installation kit $100, posi: $100, installation as much as $300.

Your looking at around 700 bucks.

 

This is a little off topic but for a very minor mod has anyone tried an injector spacer? If so how are they? I put a TBI spacer on and could notice a difference.

Thanks

 

The injector spacer is suppose to give you a 2% increase in airflow which may be good for about 1-2HP.

 

Installation can vary. I pulled my rear-end and took it to the shop and had it done for $90. They wanted way more if it was a drive in drive out operation. Tell the shop you will pull the rear-end yourself.

 

Good luck finding a posi for $100 anymore. SLP has none left right now and they are backordered for months. Look into the eaton, it is a little expensive, I think almost $400, but it is hands down the best and if it ever happens to break, which it prolly wont, it is rebuildable.

 

If on a budget, and you want gears & posi - why not hunt the yards and used parts houses for a rear with the gears you want, and just swap complete rear end? I just got a used rear from a local used parts house for $125 complete drum to drum - delivered to my door, and did the swap in a weekend by myself. It wasn't the posi 3.42's I wanted, it was a posi 3.08 - but for $125 I couldn't complain - it was posi, better than my 2.73 peg leg, and something I could afford. They also gave me a 6-month warranty. I told them to call me the minute they get a 3.42 posi or a 3.73 posi and I'll just do it all again. It even had the 24mm sway bar still attached! I spent another $175 for new brake parts, lube, posi fluid, bearings, rear springs, shocks, and Prothane poly sway bar bushing/endlink set and traction bar bushing - so complete job cost me $300 and 2 days work.

 

What about installing an LT1 cam?

 

the LT1 will definately be a big improvement and cheaper, but you will benefit more from 3.73s and then when you finally do the cam you will benefit from it more with 3.73s than you would with 2.73s.

 

The reason I asked is because I was taling to a mechanic friend of mine who said that if I installed new gears with the small can the engine would just wined up. Where as if I did the cam first I would see better initial results. He also recomended 3.42 gears over the 3.73's for my automatic daily driver.

 

with the cam you will gain alot of high end power and possibly lose some low end. With those 2.73s your car will be a dog off the line. I added 3.73 gears, posi, a crank pulley, tbichips stage 1 chip, and 6* of timing and knocked 7 tenths off my quarter mile

 

Notice any difference with your injector spacer?

 

no i couldnt feel anything but im sure it did help alittle (1-2HP like advertised), but again nothing you can feel.
if you want to do a few small mods:

ASP crank pulley ($75 with new belt)
injector spacer ($20)
www.tbichips.com stage 1 chip ($30)
advance timing (mine is at 6*) FREE
1.6 rocker arms (ill be installing some 1.6 federal mogul $60 stamped steel self aligning arms this summer)
Ultimate TBI mods with adjustable fuel pressure regulator

all of those together should knock a few tenths off your quarter mile about only cost about 200 bucks with everything at your door.

 

What are the ultimate TBI mods?

 

https://www.thirdgen.org/newdesign/t...matetbi2.shtml

they are mods you can do to the TBI to increase airflow, basically shaving down those big ridges around the throttle body bores.

 

Does anyone know why those ridges were put there in the first place?

 

i think GM just wanted to do anything possible to restrick the power of the poor L03.

 

Doesn't suprise me. They wanted to market their "wonderful" TPI.

 

well if you think about it, the stock aircleaner was a drop base with that ugly gold spacer ring, so there was really no chance of any air coming in from the sides. All the air came in from the top, those ridges probably made sure the air didnt escape right before entering the bores. Just a thought

 

But the majority of the air still has to come from the sides because the injectors block a lot of the air coming in from the top. I can see it being a rectriction even with the stock air cleaner.

 

Do what I did

head to your local u pull it junkyard and find the v6 and 4 cyl thirdgens. Look around for the ones with rearends that have no damage. Start popping off the diff covers. spin the rear to check the gears and to find the ratio.. it will be in number of teeth on pinion to ring gear. Just divide and youll find the ratio.

I found a 87 6 banger with 3.42s, took it out in like an hour and brought it home for 55 dollars. (I shoulda been more patient and looked for a 3.73 rear.. they were there, my buddy picked one up a few weeks later)

I then called summit and ordered up a powertrax performance locker for the 26 spline axleshaft rear I just bought, It was 315 dollars.

I installed the rear in the meantime and two weeks later I installed the powertrax with simple hand tools in car

with the powertrax you dont touch the gears at all or their adjustment. The only thing you take out are the spider gears in the differential and replace them with the powertrax plates.

It works better than posi because when you are going straight the axles are locked out. When you turn the teeth pop out of engagement and allow full differential. The tire with the most traction or shortest distance to travel remains engaged.


advantages
1. The gears are setup damn near perfectly.. its a GM factory install so of course its just like stock. No whining, nothing like that
2. Its easy, removing the rear end and installing another one only requires simple hand tools and no special knowledge. Same goes for the powertrax.
3. Its way cheaper than having gears and posi installed. You are looking at 500 or more for a good install.. and even then chances are you might end up with whiney gears
4. It works better than the cheapo posi youd be able to afford.

Disadvantages.
1. The powertrax performance locker will let you know its there in tight turns and regular driving youll notice it clicking and popping every now and then especially slow full lock turns. BUT the newer powertrax no slip system (which is a little more than the performance locker) supposedly is completely smooth and invisible to the driver if thats an issue to you. It has the same function though.
2. It works better than posi. Can be too much of a good thing.. I had wheel hop problems and where a posi would slip, the powertrax does not. I broke an axle shaft launching my car because of wheel hop and lack of any give (nothing else broke, i had it back on the road in a matter of hours with a new shaft). This thing is no ****.

I report, you decide

as for the ridges

I dont know this from the horses mouth but I suspect the ridges are there to totally ensure that fuel from the injector spray cone goes nowhere but down the tiny bores of the throttle body. The 454 tbi doesnt have them, it has much bigger bores


another thing
there is a button in the upper right corner of the screen that says search. Check it out sometime. Also might want to try clicking on the links on the main page to the tech section of the site there is alot of info here.