What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Searching for torque

ccarley

ccarley

1/2 ton status
Joined
Aug 29, 2010
Posts
543
Reaction score
2
Location
Rohnert Park, CA
Alright, I've been searching & searching, and during that searching, did a bit of learning.

I'm looking to increase torque out of my stock TBI 350 in my '89 Sub.

I've recently ordered the TBI spacer, which looks like a good candidate for torque by increasing runner length. I normally also run with the air cleaner lid flipped, which really seemed to help out. Now, I'm looking for some more mods that will help out, but hopefully without getting a new chip.

So, the question would be, which of these mods can I do, put together, before needing a new chip?

- 1.6 rockers
- Adjustable fuel pressure regulator
- Edelbrock TBI intake

The 1.6 rockers are of great interest to me, after "feeling" first hand what a ratio increase feels like in another vehicle. I'm not sure if I'd need more fuel pressure or not with the bigger rockers though? The Edelbrock intake looks like a good candidate to help out with torque, with (from what I can tell in photos) nice long runners on it too.

How would these modifications affect smog-ability? I live in an area in CA where the SMOG restrictions are tighter than other areas (for some lame reason). I recall that NOx is something they are trying to lower, and they are lowering what they want to see out of your tailpipe all the time.

With the SMOG issue, I'm concerned about changing the camshaft as well. I don't want to do anything that takes that much work to change back to where I was!

Thanks for any tips,
Clay
 
i put 1.6 roller rockers on mine and didn't notice any difference but i already had a mild cam in mine so that might be why
 
First off, flipping the air cleaner lid will now allow HOT underhood air to enter the engine which doesn't make as much power as cold air does. I would suggest you replace the stock air filter with a drop-in K&N filter and flip the lid the correct way. If you don't already have an injector pod spacer that will help to give more air flow, and then also install the "salad bowl" to the air cleaner housing to further help air flow. It's not a bad idea to at least check what your current fuel pressure is at (TBI runs best between 12-13 psi). If the pressure is lower than that then I would suggest an adjustable fuel pressure regulator. I would avoid doing the TBI spacer unless you also correct the TV cable bracket for proper throw after the spacer is installed otherwise you'll toast an expensive 700R4 (assuming that's the trans you have). You probably won't notice a difference going to a 1.6 ratio rocker so I would avoid that cost unless you're changing cams as well that suggest using a 1.6 ratio rocker.
 
the tv and throttle cable bracket is very simple to raise straight up an inch to match the spacer height. I just did this with mine and it came out to be the same spot it started. I spaced the front bolt (also the coil bracket bolt) with washers then cut the bracket where it mounts in the back and added an inch tall piece of metal to it and welded it back together. I had to notch one side of the bracket for the cruise control. All in all it only took about 2 hours to redo the bracket. whole job was 3-4 hours and I didnt even have to take the fuel lines off.
 
bumping fuel pressure up on the stock tbi does WAY more for performance than ANY other bolt on mod... hands down....
 
IMHO, without changing the chip programing, the options for performance upgrades are severely limited.:doah: As an experiment, advance the current timing +4 ~ +6 six degrees on your vehicle and you can feel a real "seat of the pants dynometer" difference. The only drawback for leaving the current timing advanced +4 ~ +6 degrees is starting the engine in hot weather.

dave w
 
Thanks for the replies!

I'm not exactly looking for making more HP, just low end power. I guess there's not a whole lot that can be done before modifying the chip.

I do plan on correcting the TV/ throttle cable bracket, and even have a new TV cable on order. Previous owner... ugh... the cable is wrapped around the throttle arm.

I'll have to look up what an "Injector Pod Spacer" is; I don't think I've seen (or heard of them); I figured from the other posts I was reading it was a different name for the TBI spacer!

As for my air filter. More previous owner shenanigans. I have none of the stock ductwork going to my air filter assembly; it's sucking hot engine compartment air no matter what. Flipping the lid made a good difference, although it is loud.

I'm surprised that the switch to the 1.6 rockers doesn't make too much difference. Now, my previous experience was in an air-cooled VW engine; switching from the stock 1.1:1 rockers to 1.25:1 rockers made a real difference. Then again, 140 HP in a VW Bug is a lot!

Thanks for the advise. I'll keep you all posted. Again, the biggest concern I have over anything is smog. If I can't smog my Suburban after doing certain mods... they weren't worth it! Unless I had a '73 that is... then I'd have no concerns :)

Clay
 
Here is what the injector pod spacer is and does. http://marine-performance-parts.com/cfmtechinjectorspacerforgmtbi435057.aspx

injectorspacer.1.jpg
 
thats where I'm at right now. I have the spacer but they didnt send any gaskets or longer screws:dunno: I guess I have to improvise wisely
 
I was looking for torque like you, mine was because it would hunt in and out of converter lock up at highway speeds. The tbi spacer and and salad bowl are the biggest things I did. I can cruise along at 65 and it just seems like its idling. I have a slight off Idle hesitation but that may be timing.

Do the spacer and salad bowl for sure:waytogo: Neither of them should affect smog. I upgraded the coil too which also shouldnt really cange the emmissions much and was cheap.
 
in ca i am not sure what you can get away with but for a bolt on power incress. full exaust system from motor back. the stock tbi system and old pancake cat with tiny pipe dia of the y-pipe its a huge choke on the system.

brian at tbi chips did cheep ebay shorty headers and custom made y=pipe with 2.5" pipe and flow master y-pipe build peice http://www.summitracing.com/parts/FLO-Y250300/ then good highflow aftermarket cat and aftermarket muffler.

this got him basicly 40 more hp and around 50 tourqe at the rear wheels.
 
dave w said:
The spacer pictured above are stock to 454 Throttle Bodies. The parts stores should have them / can get them? Heck I guess it's possbile to sandwhich two 350 throttle body gaskets to make the same thickness as the 454 gasket / spacer?

dave w
Click to expand...

Dave is correct about this being stock on 454 TBI units. I had one on my 350 TBI and when I swapped to the 454 TBI I noticed it was the same thickness but I added the extra spacer as well and just came up with even longer bolts. :D
 
Thanks for all the helpful info!

I'll be ordering the pod spacer today. It should help HP, which is always good I guess, but it's super cheap anyway so why not.

Salad bowl will be next on my list then.

The exhaust is indeed stock to the cat, then a decent size system from there back with a flowmaster, single all the way back. It's probably getting a new cat soon, since it's original, so I'll see what I can do there. Can't order cats in CA anymore :(

I might check out an aftermarket coil; I had ignition system issues a while ago and replaced the coil with a stock replacement from autozone. Just last weekend I finally installed the Accel HEI module in the distributor, and noticed it runs much more smoothly when warmed up at idle. I have to check the mileage number still from the last couple of weeks on that change, but it's all documented.

Thanks again!
Clay
 
well, guess I'll repeat myself... other than maybe some nice headers, which is way more money and labor, no spacers, salad bowls or ouiga boards will give you a more noticeable increase in torque/power than a fuel pressure bump.. even with the stock chip...
 
The regulator would be easy to get to when you have it pulled apart to do the pod spacer wouldnt it:thinking: I'll have to wait till I can get an adjustable to do my own pod spacer. Somewhere on here I seen a tbi that had a variable regulator deal,,,,, ran off of a vacuum fitting welded to the regulator or something:dunno:
 
ryoken said:
well, guess I'll repeat myself... other than maybe some nice headers, which is way more money and labor, no spacers, salad bowls or ouiga boards will give you a more noticeable increase in torque/power than a fuel pressure bump.. even with the stock chip...
Click to expand...

That's definitely on my list!
EDIT: I must have been sleep typing this morning at 6:00am... my list is larger, not necessarily in this order:

Fuel Pressure adjuster
Pod spacer
Salad Bowl
Still considering the 1.6:1 rockers...
Maybe the Edelbrock TBI intake. If I feel like the work.

I just installed the TB spacer today, and took it for a spin to the store & back. I filled up last night, so this should show a good mileage change, if there is one, next time I fill up.

I may need to move the throttle cable bracket; I was able to adjust the trans cable according to the directions; I probably should have done that when I got it! It shifts a bit later now. The PO did say they rebuilt the 700R4 with at least a shift kit (I don't know what else they did) because they took it to Pismo Beach a lot. Probably didn't adjust the TV cable to the trans though, and it always felt OK to me, but nothing special.

The throttle pedal is higher now, since I didn't move the bracket or anything, and well, feels way touchy. Probably due to the added torque the engine has now. Fires up faster too.

After installing this... I just wonder why it's not the first thing anyone does to a TBI motor? Cheap, quick, and easy... how can it get any better than that?

Clay
 
well, the salad bowl is by far the easiest mod you'll ever do....

keep your eye on the trans and that cable geometry for the tv... make sure your not getting a wear spot or anything....


I'd do the intake in a heartbeat before 1.6 rockers unless i was doing the whole topend...
 
do you directly try and fire when first turn key ?

or do you turn key on and wait 3-5 sec for fuel system to prime up ?

this does make a big diffrence on some systems.
 
You must log in or register to reply here.

Latest Posts

Top Bottom