my TBI builds

[TylerZ281500]

Ive seen alot of TBI questions going around do i figured id make a collective of the engines ive built using the tbi systems.

first off 383 tbi from the top down

ultimate tbi mods, slightly ported tb, 454 injectors bumped fuel pressure
carbd intake dual plane with adapter, injector spacer. older style weiend dont remember the name
low mileage LT1 cam, roller converted
Dart torquer heads ,1.6 roller rockers
Eagle stroker crank, Hypereutectic dual valve relief pistons, forged rods
summit oil pan, taller valve covers, MSD ignition, delco plugs etc etc
Long tube Headers(flowtechs.......dont recommend)
TPI fuel pump
compression was 9.8:1 IIRC
definiteyl was one of my favorties, truck had alot of low end torque, it tuned out rather nicely but was pulled and sold due to the truck having frame issues.

Next is the 350 i built for the yukon but was waaaaay to much

forged crank, .030 overbore, dual valve relief pistons
Dart aluminum heads
single plane intake
cam was ridiculous close to about 501 lift, not enough LSA etc etc
1.6 shaft mount rockers
tried using a bored out 454 TB with Maxxed out injectors.
10.5:1 compression
Using the stock computer it wouldnt run worth a damn. sold the engine and the guy carbd it.

with that cam and all those mods and the higher compression it was stupid of an idea to build using the tbi system. i wouldnt reccomend it

350 in the yukon now
Ported polished tbi heads (overported them in a few places and ran through the wall of them)
Edelbrock TBI intake i had laying around
TBI mods, stock 350 injectors with upgraded fuel pressure.
TPI pump with regulator
injector spacer
had pos spacer but took it off( the edelbrock intake has a spacer built in heigt wise so my linkage needed to be moved up, didnt feel like doing so so i took it off)
421/444 112LSA cam
Roller tip 1.5 rockers
double roller timing chain.
Block mods include oiling mods and lots of polishing
Summit deeper oil pan
MSD igniton
Custom tune(datalogged frequently)
stock lower end but used a thinner gasket to bump up compression
still running on regular though.
shorty headers, custom exhaust
12.5-13mpg consistantly

Best one as far as streetability, mileage and daily driveability so to speak. took me forever to get running right because my computer was shorting out in gear and i couldnt trace it.

so far the yukon on top of that has electric ls1 fans, 2200 stall, vette servo, shift kit, 3.73s with trutrac, 33's etc. by far my favorite. friends always ask to buy it off me. not much id change on that build besides maybe going LSX

overall just sharing my experiences
as far as stock TBI mods without going into major engine work ive done many TBI ultimate mods, spacers and injectors. they can be done cheap, tuenups uncluding fuel filters do wonders when they seem to start to run rough from my experience. Electric fans helped nicely with mileage and warming and cooling the engine. and it cleans up everything nicely.

any questions ask, not saying these engines are the best for you its just my experience with them ive done a few other head/cam/intake jobbers as well but not worthy enough to list. if anyone has questions or interest in anything just ask.

 

[GMRedline]

I got some newbie questions if you don't mind?

It sounds like you went from wild to mild with your builds.

What is your main goal with your truck?
What is the stock CR of the L31?
What type of fuel are you running in your truck?

In your second build you mentioned the combo of the cam, mods, and increase in CR did not work well on a TBI system. Would you contribute that more toward the design of the TBI system or the combo of the mods?

The purpose of my question is specifically toward CR. I have a burb which I only plan on using for towing and daily driving. So low end TQ and fuel economy are most important to me. I have considered a very mild engine build which might include a cam, pistons, and some head work. I would like to increase the CR to take advantage of high octane fuel but need to get more information on how the engine reacts to different changes.

Again, sorry for the newbie questions but you said to ask.

Thanks!

 

[TylerZ281500]

the 88 with the 383 was built for a torquey daily driver, with some towing but mostly just a street ripper.

the yukon with both 350s is just a daily driver that i tried to go wild on only to get a brain and figure out that i should keep it all around to have decent mileage good driving manners and decent towing ability.

i run regular gasoline usually. the truck does seem to like a little higher octane but it doesnt change the behavior all that much so i couldnt justify the cost of higher gas prices.

as for the second build not liking the tbi system mainly the computer didnt want to read the vaccuum of the engine, it was very hard to tune to get it to run even decently with as big of a cam as i had as well as the higher compression i imagine didnt help. From what i heard that engine became carbd and went into a camaro and he was runngin low 11's high 10's with some minor tweaking if i remember right. overall TBI shouldnt have been an option for that engine at all.

your suburban if we are speaking of the 99 is a vortec motor. i see alot of 383 builds, ported heads, lt4 hotcam or RV type cam builds for those engines. you will need or at least benefit from a tune regardless of it being TBI or vortec. i would keep your compression right around where it is a slight bump may not hrt if you ported and polished your heads somewhat. again id look into some of the Vortec builds around here as from what ive seen TBI and vortec are entirely different animals when it comes to building them. ive had little experience with vortec motors so i dont want to steer you in the wrong direction but from the norms if upgrading to a lower end i see alot of people happy with 383 builds, 411 pcm swaps, marine intakes, ls1 Throttle bodies and so on but i would look into those engines in specific more

 

[one320fc]

Tyler thanks for all the info! Now a more important question I should have asked with my thread is from mild to wild how does the rear and trans handle the extra abuse? I ask cause a friend of mine I think slightly blue oval bias said our rears are not worth the metal they are made out of. I'm not planing on doing hole shots, drag racing, but I do plan on trying to get it stuck a few times and throwing on 33's and a 3" body lift.

 

[TylerZ281500]

My yukon currently has a 14 bolt with a trutrac. the 10 bolt was shot when i got the truck. i can say that you can keep any stock rear alive without beating on it too hard, the gov locks on the other hand have a mind of their own and can grenade without warning.

Id say if you have the money, and feel that its necessary its good to upgrade. the larger brakes helped a bit with stopping as well. is it necessary? no theres alot of people who never touch their rears and they live a long time others not so much.

as far as transmissions it depends what one you have. my 88 and 93 both have the same mods although being different transmissions. both had vette servos, shift kit, stall, etc. I bought the kit for Probuilt automatics for my current trans as ive dealt with them in the past with my camaro. Great price, great parts in my opinion and theyll answer any questions you have.

 

[DCorvin]

Are the rebuild kits worth it if you're creeping up there in miles?

Sent from the Z71

 

[95Escahoe]

Are the rebuild kits worth it if you're creeping up there in miles?

Sent from the Z71

Deff worth it, you'll be shocked at how dirty your TBI unit is, and rebuilding it is quick and easy

Sent from my HTC One X using Tapatalk

 

[DCorvin]

Deff worth it, you'll be shocked at how dirty your TBI unit is, and rebuilding it is quick and easy

Sent from my HTC One X using Tapatalk

Thanks I was really considering it when it warms up some!

Sent from the Z71

 

[95Escahoe]

Thanks I was really considering it when it warms up some!

Sent from the Z71

No problem, do the TBI mods too while your at it

Sent from my HTC One X using Tapatalk

 

[gmcyukondriver]

I'm going to assume you had a custom computer tune on the 383, right?

Do you know if you can run 454 injectors on a 350 without having to re-tune the computer? I would think that the O2 sensors would be able to adjust the cycling of the injectors to run right, I was just wondering if you knew.