Small Turbo on stock L29 454?

[SNOMAN]

So like many others, I've been watching the Richard Holdener videos on youtube. I am wondering if anyone has put a small turbo on their L29 454. I am contemplating upgrading my engine with a comp cams 212/218 cam, brodix/afr/edelbrock aluminum heads, headers and possibly bore and stroke to 496. I have a 0411 PCM already. The question is, is it worth it or should I do a duramax swap?

 

[618 Syndicate]

What is your intended goal?
Small turbos like rpm which is not the forte of a big block, a larger turbo or blower is better in most low rpm applications.
As far as a diesel swap goes, you achieve just about any goal with either gas or diesel, just comes down to refined you like your hydrocarbons.

 

[SNOMAN]

What is your intended goal?
Small turbos like rpm which is not the forte of a big block, a larger turbo or blower is better in most low rpm applications.
As far as a diesel swap goes, you achieve just about any goal with either gas or diesel, just comes down to refined you like your hydrocarbons.

Nothing crazy. I'd just like have more power for street with some towing every once in awhile. I'd like to have better hp than what the newer gasoline trucks are making and I'd like to have about the same torque as a LB7/LLY/LBZ duramax.

Could I just get this result from a turbo instead of spending about 5k+ to get the same results with N/A?

 

[Aparke4]

In as I want to go this route vs. blower/ supercharger. Turbo parts and kits like STS are plentiful vs discontinued supercharger kits or $$$ kits like vortec. With the 0411 swap, larger injectors and a high output fuel pump and either a remote set up post cats would be a very simple/ ample room install that would actually be fun! If you want to go underhood then there are multiple manifolds that will house either single or dual turbos. Lots of crossover from guys swapping the L29 into street/ racecars.

http://www.ssautochromeinc.com/turb...vy-headers-manifolds-header-v8-chevrolet-bbc/

Cool build for reference:

https://www.hotrod.com/articles/junkyard-454-163-ebay-turbo-700-hp/

 

[LC2NLS6]

What is your intended goal?
Small turbos like rpm which is not the forte of a big block, a larger turbo or blower is better in most low rpm applications.
As far as a diesel swap goes, you achieve just about any goal with either gas or diesel, just comes down to refined you like your hydrocarbons.

Small turbos are small turbos, you should size the exhaust hot side that can flow what the engine is moving. For example, in the above hotrod article, they got 8 psi boost to the intake and 22 psi backpressure in the exhaust. Ideally, get that closer to 1:1 boost ratio on both sides of the turbo.

Don't forget to upgrade the fuel system.

 

[yevgenievich]

Been thinking mild set of twins for same application but gave up for now until can get funding to upgrade the pistons. Then likely transmission would need help as well

 

[SNOMAN]

Thats my concern. I'd like to run the factory efi and I don't think it could fuel a bigger turbo but I figure with a bigger turbo I could just run a lower psi like 5psi.

 

[LC2NLS6]

I like my comp 215/215 270HR roller cam in my Gen V. Would be good for a low boost tow machine with its decent .566 lift. Go with too small a turbo, and you'll have a very hard time keeping it from spooling up off idle. You do not want full boost at low RPM part throttle. Low rpm + boost love you long time = mega high cylinder pressures = lots of torque, until something snaps. That's why a good EFI system and proper sized wastegate lets you keep rock solid boost without spiking it down low.

(I own and raced turbo Buicks since 2000, wrenching on them since 93 with buddies GNs.)

The 215 magnum
https://www.compcams.com/magnum-215-215-hydraulic-roller-cam-for-chevrolet-big-block-396-454.html

 

[Christian Steffen]

So like many others, I've been watching the Richard Holdener videos on youtube. I am wondering if anyone has put a small turbo on their L29 454. I am contemplating upgrading my engine with a comp cams 212/218 cam, brodix/afr/edelbrock aluminum heads, headers and possibly bore and stroke to 496. I have a 0411 PCM already. The question is, is it worth it or should I do a duramax swap?

Turbo BB vs dmax just depends on what you want for efficiency. Dmax will get great mileage, but they're expensive and a lot of work to swap. Turbo BB will get OK mileage if you can stay out of the throttle lol The dmax will make more torque at lower rpm, and sustain it much longer, but if you're not towing a lot the BB will do fine.

My rear mount turbo is just a gt45, but it is definitely small for the application. I think the heat loss from the turbo being 10' from the engine helps out with back pressure though, and I'm also only running 5 psi. As is back pressure is around 2:1, which is obviously higher than ideal, but could be worse. The turbo I'm running was mostly to get the system up and going, I'll upgrade it to a s475 or s480 eventually, but I need more injector and a walbro 450 first.

Currently I have a walbro 255 and 36 lb injectors ( flow ~42 at 58 psi), the injectors are maxed out at 5 psi the 255 is keeping pressure up so far but I am probably close to the max.

If you aren't planning to go much above 500 hp a walbro 255 should be enough, and a set of 36 or 42 lb injectors should work.

Stock injectors won't support much, so don't plan to use those, and I wouldn't trust the factory fuel pump personally.

 

[618 Syndicate]

Small turbos are small turbos, you should size the exhaust hot side that can flow what the engine is moving. For example, in the above hotrod article, they got 8 psi boost to the intake and 22 psi backpressure in the exhaust. Ideally, get that closer to 1:1 boost ratio on both sides of the turbo.

Don't forget to upgrade the fuel system.

Agreed, but small turbos don't move as much air as bigger ones. Boost is nothing more than an indication of restriction, a bigger turbo will move more air (and support more power) for a given boost pressure.