Looking for input on engine size for my next build.

Current setup:

• LS2
• A&A TI Trim (3.4 pulley)
• E85
• BTR blower cam (227/224 .618/.604 115+5)
• A&A dual pump fuel system (planning larger injectors and Fore system)
• Stock bottom end

Trying to decide between:
364 / 376 / 402 / 408 / 416

Main question:
Which displacement works best with a centrifugal setup without turning the car into a low-RPM torque monster?

Target is around 900 WHP. I know any of these can get there, but I’m trying to figure out what makes the most sense as a well-rounded setup. The car will see street driving, events, rolls, and digs—something that performs well across the board, not just chasing peak numbers.

I want to get the engine choice right before buying parts and have a solid plan going in. No matter the route, the block will be sleeved with Darton sleeves.

Looking for real-world input from similar builds.

 

Stock displacement with forged rotating assembly can handle 900 no sleeves required.

You upgrading blower too? Ti will be hard pressed to make that power.

 

Your blower cam specs are wack. If money isn’t an option, I’d run a 402 with LS3 heads. I made 850/800rwhp setup on a 232/244 118+2 cam on 93+meth 15 years ago that idled like a stock car. Almost no lope with a T(not TI trim). Car was quick. You can run the stock cubes but the sound of the stroker and the torque without reving it to the moon to have fun are worth it. Had cars with YSI’s, Novi 2500’s and not my cup of tea. My stock bottom end, stock head LS3 vette makes 864rwhp and rips with the TI and only a 3.5 pulley.,Has decent mid range, but I’d still take a larger engine.

TI is plenty for 900. Know a guy that made right at a 1000rwhp and it’s completely believable considering where my car is at with only a 3.5. With my old setup if a TI and E85 were around, 950 would have been a breeze.

 

I wouldn't say that I have an unlimited budget, but I am willing to spend the money where it counts. I know I do not want to rev it to the moon which would probably cut out 364 & 376. So I can definitely add a new cam to my list most likely will go custom at this point. If I need to switch blowers I will but if my TI can make it there id like to keep it and spend that money on other things.

 

Trying to decide between:
364 / 376 / 402 / 408 / 416

with your ls2 the only stoker possible option is the 402. to want 900whp on the t56 is not likely to live much, it''ll be a ticking bomb, hopefully not a 05 or you'll need to upgrade the diff before even reaching that much power. you'll likely need a F1X to get 900ish. it will be fun for about 6 weeks tops so make proper arrangements for that

 

You list a SBE. If you are changing crank and pistons anyway, why would you not use forged parts?

I personally would not go to a larger piston without sleeving. Have you ever seen the sleeves on a factory engine?

I just did something similar, went with 427. More torque is available from the engine until the SC gets its legs.

I want to see how close I can get to 1,000 WHP on E85. The SC is a Ti with an aftermarket billet impeller and high speed bearings. I have been running it on a SBE LS3 with a cam. I limited the boost to 9.5 PSI to keep it to ~750 WHP.

 

My 2005 LS2 made 843whp with a V2Ti for years, on a tire too. I was strictly roll racing, no launches (upgraded diff). Wheel hop is the real killer.

 

I already plan on upgrading the diff and transmission as there isn't a stock unit out there that will hold that much power for long. I just wanted to focus on the engine build primarily right now as the diff and trans is a simple phone call to RPM.

I am forging the bottom end which was my question of the final displacement I should go with, if my TI trim will get my to my goal i would keep it rather then shell out for another headunit. I think my best bet would be a darton sleeve 408 from the responses I have gotten, I think a 416 or 427 wouldn't be a good match for the current blower I have and that is probably the easiest to swap out and a sleeved 408 with forged internals will definitely be able to handle a YSI or F1X.

 

years back when I spoke with the guys at A&A (as well as tuners) and they advised smaller displacement and let the boost do the work....(less rotating mass). also there is some argument on the fact that on some stoker builds, the piston comes to far out of the sleeve and creates more wear/stress

 

Both PowerBore and Darton sleeves are longer than factory sleeves. Another reason to resleeve.

Unlike the A&A method, I went with the larger displacement which gives you greater base power and torque. Also, you are operating in a lower boost range which gives you a wider tune window.

I am not yet able to read a pressure map which would probably answer a lot of questions for me.

The 427 should respond better to a larger SC if/when I upgrade.

 

couldn’t agree with this more. I’ve had Forged LS6’s with a stock stroke that make 25+psi with a Novi 2500 where my higher compression 402 with a little Novi 1500 maxed out at 13PSI is so much snappier and enjoyable since you don’t have to run it to 7000rpm. It’s instant power, especially for us stick guys

 

sent you a PM

 

That snappy feel is what I'm after, A Ti-trim on an LS7 at 8-900whp accomplish this?

 

Remember we all have different options ,different experiences and build setups different ways. This is just my .02

If your car is geared more towards track style events aka prep style surfaces or 1/2 mile, 1mile events then go with big cubes. 416/427 etc, etc, etc. On a prepped surface you can stick all the added torque and hp.

If you do a lot of street pulls then I'd say 376 and run more boost is the way to go because the road becomes the equalizer. Big TQ is not your friend. I went from 875whp/688wtq with a V3TI making 14.7psi to 933whp/796wtq with a cammed SBE LS3 running a V1TI on 16.2psi. On the V3 the hooked like it was on the track when making street pulls. Made the swap and battled traction. Rolling into the pedal hammered the tires. Tried 3-4 different sizes and brands. Wicking the mid-low range blower up that much it was a stump puller with TQ. When the SBE gave up the ghost I built a forged 376 with a larger head unit . Started with a 2200hd, moved to a AFI91 and now run a G3R running 24-25psi. When I went LSR I went with the smallest cube they offer which is a 388. Basically a big bore 6.2. I have run the stock pcm with just about every tire out there, I run Kelitrac suspension and I have been running a stand alone aka PRO EFI that has racing TC for the past 4 years. Testing Different tires and heights on different surfaces combine with buddies that also have racing TC/stand alones with cubes and big power who also test different tires and heights. What we see from the logs is that the big cubes on the street spent a lot of time in traction control pulling a ton of power and really only get to shine past 120-130-140mph compared to mine thats in TC till about 75mph (with the forged 376) doing 60-160 pulls. I have some friends that have come down from 427's to 400's. You every see people that dyno 1000whp and get beat by someone making 800whp....... Wonder why coyotes work so well and plant the power....cough* no tq

If your goal is 900whp with a V3TI that is doable with a 416/427 because the motor itself will make more power NA vs a 376. With a 376 its a stretch in reality. Most 376's tap out in the mid 800's. 900's is just not common for a TI. A few people here or there have hit those numbers which could be a friendly dyno or mine shaft air. I'm not a dyno racer I care about what the car does on the street. Have had cars dyno in different shops with no changes and pickup some serious power. Its not as mainstream as people think today. At 900whp they should be running low 4's 100-150 on a dragy at 933whp I would run a 5.1 60-130 pedaling and a 4.2 100-150. My V3TI would make 831whp in the Texas summer and 875whp in Texas boost weather months. My buddies with a similar combo made 825whp. Different dynos! I would run hook 5.1/4.7 60-130/100-150 and he would hook a 4.9/4.5 60-130/100-150.

A great unit for 900whp plus would be a D1X, JTB or G3X. I have a buddy that made 921whp 3.62/10% cammed LS3 and 1022whp 3.37/10%. Car was fast AF!! His best 60-130 was 4.3/3.8 100-150 rowing gears.

I'm a big fan of the ESS units. No fancy oil, self contained ,big step ratio so no baby pulleys, high max impeller speed, billet wheel and 5k over spin burst. They pour boost on fast AFand pull like a freight train up top! A buddy of mine that's not local but we have been chatting for about a 1 year and half just installed a G3X on his C6. He saw me running the G3R and had questions. He came from a V3TI making 807whp running a 5.3/4.8 and wanted 900whp plus I recommended the G3X. He has a forged 6.2 and is battling some fuel issues when it makes over 20psi but still made 955whp@5600rpm /965twq@4900rpm. And at 7000rpm the blower is not even at max impeller speed. Based on the TQ I could see it making 1050-1075whp@6400-6500rpm if he decides to let that dog eat once the fueling it sorted. Even with the car not pulling strong to 6500rpm it still went 4.8/4.2 deep in traction control leaving in 2nd and 2 shifts. What more impressive is that the car went 4.8 leaving in 3rd. To give you a point of reference.. Back when I had my snappy V3TI 3.47/10% would run 5.1 with 2 shifts leaving in 2nd gear. It would go 6.2 leaving in 3rd and that's removing 1 whole shift and waiting on boost even being spun that hard.

The YSI and F1X are really 2 different animals. I wouldn't blink at running a YSI on a sleeved motor but a F1X is aftermarket block land. F1X is drastically under rated. While a YSI or YSIB in a killer 427 setup can make 1000-1200whp which many engine builders don't like sleeved motors making 1400-1500crank. A F1X can make 1400whp plus. Something to remember when it comes to Centri's is that it take power to make power. Rule of thumb is 10hp per 100hp. So at 1200hp crank it took the motor 120hp to turn the blower.

 

Great write up! I'm going to be running the Haltech nexus Rebel LS on my Z06 (built/sleeved) and am looking to build a snappy around town/spirited driving car (done with serious street racing)....what setup would you recommend? centri or PD?

 

Haltech is awesome! My tuner had one on his wife's boosted C6. All the safety nannies will protect the investment. Aftermarket TC is awesome and pro longs the life of drag radials if you run them! A 2650 KONG is legit if you want to spend the money (15k plus). The 2300 Maggie is very limited due to the size of the pulley shaft. I believe the smallest pulley can run is a 3.10 after the shaft is machined down. A 2300 on a 427 really chokes up the motor and the setup is just expensive. With cubes I would recommend the G3X if you have power goals from 800-1050whp. Flows 1600cfm and rated for 950whp plus with a max impeller speed of 70k bursts to 75k. Ess pours boost on fast!!

My old motor was a forged LS3, 230's cam, TFS255's and stock intake.. From WOT pulls logs here are mid range boost reading. The 2200HD pulley to over spin at 7000rpm. The AFI and G3R are not.

2200HD 3.12/10%
5000RPM 11.5PSI
5500RPM 13.5PSI
6000RPM 15.6PSI


AFI91 3.40/10%
5000RPM 10.4PSI
5500RPM 12.7PSI
6000RPM 14.7PSI

G3R 3.40/10%
5000RPM 16.2PSI
5500RPM 18.6PSI
6000RPM 21.0PSI

On the LS3 with G3X I mentioned earlier pours on power more like a PD which is why he was able to run a great time leaving in 3rd.

 

goal is 850-900whp

 

What's the whole combo? Heads,intake,cam etc? fuel?

 

Darton sleeved 427ci, Callies crank/rods, Wisco pistons, PRC heads, 234/246/112.5 cam, fast 102 , NW103, airaid Cai, flex fuel

 

Is the intake square port?