87 tbi upgrades

[Garcia_1971]

I have an original 87R10 TBI, i wanted to get more horse power, but keep the tbi. Looking to replace heads and install new cam. Any ideas.

[andyh1956]

If you want to replace the heads go with the Vortec heads & a new GM Vortec / TBI conversion manifold.
Our 88 K5 Blazer has a Comp Cam for a TPI engine that runs well w/ no computer mods.
Put some flat top pistons in there, a heated O2 sensor & a set of headers as well & it will run pretty good.
Here's some more info
http://tbichips.com/?page_id=73

[Nick_R_23]

TBI and horsepower don't really belong in the same sentence. +1 for the Vortec heads though, that's about as much effort and money as I'd spend trying to get any performance out of the TBI system. You can go with flattops, ECM friendly cam, and headers as stated above, but at that point I'd be looking at going with a system that isn't the equivalent of an electronic 2bbl.

[Mattchu60]

TBI makes changing parts very difficult. It may be able to adapt to closed loop style driving (cruising, light acceleration) but the moment you go into open loop, your computer will run off pre-determined fuel tables in the ECM, it ignores the O2 readings so you won't take advantage of the upgraded parts.

What you need is to have the ECM reprogrammed. I know TBI chips has been suggested, but I would suggest what I am using instead - Dynamic EFI. Its a very steep learning curve, but after time you will start to understand it. In a nutshell, you send your ECM to the owner of the business, he replaces some of the boards inside with updated tech and you get an ECM back that is able to "learn" to a limited degree and also is fully programmable with a laptop.

I am running the following combo - Iron Eagle heads, around 9.4:1 compression (wanted to run 87 octane) pistons, edelbrock intake (non-TBI), using a plate to mount TBI on the intake i got off Ebay (its nice quality - I think its Inject-it brand?), Holley 670 TBI and a comp TBI friendly cam - 1,000-5,000 rpm range.

This combo is working great for me - I think vortec heads and the GMPP TBI/Vortec intake would also be a great choice.

If you stick with stock TBI - get the adjustable regulator and a handheld gauge so you can check the pressure and adjust it.

The single best thing you can do for tuning after you have all the changes made is this - wideband o2 sensor. This will give you a massive amount of data for tuning - the stock O2 sensor is narrowband. Plus the Dynamic EFI system I mentioned above will talk with a wideband O2 sensor and you can have it learn the full fuel table using it.

Also you can adjust timing and other things with Dynamic EFI - cant say enough good about it - the guy who sells offers great tech support (email only). Although I will say again - learning curve is very steep and takes a lot of practice.

[Garcia_1971]

I appreciate the suggestions guys, my engine is pretty much stock, just wanting to get a little out of it. I definitely wouldn't be opposed to changing heads, cam, and maybe even going to upgraded EFI system.

[andyh1956]

Originally Posted by Mattchu60

I am running the following combo - Iron Eagle heads, around 9.4:1 compression (wanted to run 87 octane) pistons, edelbrock intake (non-TBI), using a plate to mount TBI on the intake i got off Ebay (its nice quality - I think its Inject-it brand?), Holley 670 TBI and a comp TBI friendly cam - 1,000-5,000 rpm range.

Thanks for the tip on the adapter plate!

OP if you want the Part #for the cam we used let me know I still have the box it came in. Comp Cams recommended it & it pulls good!

[57NAPCO]

Originally Posted by andyh1956

If you want to replace the heads go with the Vortec heads & a new GM Vortec / TBI conversion manifold.
Our 88 K5 Blazer has a Comp Cam for a TPI engine that runs well w/ no computer mods.
Put some flat top pistons in there, a heated O2 sensor & a set of headers as well & it will run pretty good.
Here's some more info
http://tbichips.com/?page_id=73

Thanks for the link, that’s a good one for TBI folks.

[DieselSJ]

Originally Posted by Nick_R_23

TBI and horsepower don't really belong in the same sentence.

That is a rumor that is spread by people who do not know how to work with them. There are guys over on the 454SS forums who are pumping out over 600HP with TBI. Great tuning tools are available for the computers. The injectors will handle more than 60psi of fuel pressure so they will support a lot of HP. Big block versions flow 670cfm and they can be bored bigger.

[sweetk30]

adjustable fuel pressure regulator and 13psi with gauge kit to see its there makes power . stock can be 9.5-11ish at best .

heard setting timing to 4* over stock 0* is a tweek .

tbi mods = chip burn .

stock exhaust is a HUGE restriction on these trucks . and the stock old school pancake cats were major choke points . when i swapped mine out years ago on a truck i had it was like adding 30hp to the truck . seat of the pants feeling of more power .

if it was me do what ya want and go carb intake with 4150 flange on it for the style of carb . then get a fitech or snipper efi unit and smack on there and be done . last mod is swap fuel pump for a 96 c3500 350 truck pump to get the psi required .

all the money and time and mods to keep a 2 injector tbi unit . . . i think is better spent on a snipper or fitech . then you can make changes later YOUR SELF ! no chip reburn .

[Dayton601]

I had originally set up my 91 TBi 4300 pound truck with all the external goodies you could get, and ran it at the track, went from mid 16s to low 15s, did the TBI spacer (plate between TBI and intake) the injector spacer (small piece between TBI body and injectors, changed the coil, added headers, transmission went out, . beefed it up to better clutches, and corvette servo, made it to high 14's ... all the while i was getting 21 to 23 miles to gallon on hwy, later added Vortech super charger, went to 13.6 ...blew head gasket, re did heads blew it again, rebuilt motor added low compression pistons, also comp roller cam, not sure lift, but I know its some like that came in the irocks at the time, added set of Trick flow heads, the bad is i never got to run the blower after the rebuild, due to it pre-detonating (popping/ backfiring) never got to run it at the track, because I totaled it out on a slippery road,

[Dayton601]

with that said I am still running the motor in a 2300 pound car, 1929 model A sedan, but i had to take the blower off, too dangerous, later added roller rockers, the motor runs great, some times it seems a little rich on the gas, most likely due to the low compression pistons, but it runs great, with the tbi, , its super simple to work on, Im sure a super chip programmed would make it run even better,

[andyh1956]

If TBI is nothing else it's Reliable! The old '93 WT I just traded off had 326K miles on it & sometimes it was the only thing in the yard that would crank!

[Desert1957]

My 87 has an upgraded 1992 5.7
TBI chips prom in the ECM
Camshaft that "TBI Chips" recommended
New Injectors
Complete dual exhaust with Mustang full flow cats,stock manifolds
400 Turbo (375) with a shift kit
3.73 rear end , 31" tires

Starts every time , reliable , decent fuel mileage, good power, even tows decent.

I will tell you the cam change and computer upgrade was the most notable performance upgrade, better power curve and performance. But also had mpg increase, showed how lean the factory setup is.

[Nick_R_23]

Originally Posted by DieselSJ

That is a rumor that is spread by people who do not know how to work with them. There are guys over on the 454SS forums who are pumping out over 600HP with TBI. Great tuning tools are available for the computers. The injectors will handle more than 60psi of fuel pressure so they will support a lot of HP. Big block versions flow 670cfm and they can be bored bigger.

It's not a rumor, it's just a fact of life. With enough time and money you can do anything, that's no secret. The TBI is great for what it was meant to be, and that is cheap, simple, reliable fuel injection. There are also people running 600HP from an Inline 6, but there is a reason you don't find many people doing it: Just because it is possible, doesn't mean it's a smart or economical way to spend your money. I stand firmly behind my previous statement that I wouldn't waste any more time or money on a TBI system besides upgrading to a set of Vortec heads. The return on your HP-per-dollar ratio with a TBI system with any other upgrades is just terrible.

To the OP, you never mentioned what you actually use this truck for, or what you're hoping to get out of it or make it do. If you are willing to make some changes outside of your engine, you might end up happier with the results. I'm assuming since this is an 87 1/2 ton with TBI, you have a 700R4. If you don't already have them, upgrade to a 3.73 (or lower) ratio. If you have a 2.73, 3.08, or 3.42, gear ratio right now, swapping to at least a 3.73 will go a long way to waking that truck up. The stock 700R4 shifting calibration leaves a LOT of room for improvement, too. Even an off the shelf shift kit will greatly improve the way your transmission operates, and I'd recommend having the governor springs and weights tuned to the truck as well. Lastly, I suggest a QUALITY torque convertor, with a higher stall, and also a good external transmission cooler. FTI, Circle D, and Yank all make excellent convertors that retain stock drivability characteristics, but can instantly flash to the torque peak of what your engine is producing when you get on the throttle, allowing you to actually take advantage of the power your engine is producing. A well-matched convertor alone can make it feel like you've added 100hp.

I know everyone wants to start by diving right into upgrading their engine, but if you address these areas on your truck first, I believe in the end you'll come out happier with your truck and be able to enjoy it more.