190 is impressive! Unfortunately I don't have the funds or engine to be going that fast. But it backs up my point. For 1000 HP goal, yes... the S366 would outperform the 78/75, esp on a 5.3. They are just too big for what most are doing w small bore motors. They and would be lazy compared to the S366's. Id even say for goals under 1200hp, the S366 is still a better choice. Just not the most economical choice. I figured if I over turbo'd my setup Id have lower charge temps and maybe squeak by without an IC to the 900ish range. Just hope I can get them into boost on the brake. I have a 1925 Model T I'm building and space is a premium! Hate to hear that about the $270 ebay clone... hope I have better luck! Did they just start smoking or did they shell out? Did you use oil restrictors or anything? -thks!

 

Vsr 80 25psi 3200lbs 3.27 gear

 

Might call up Viren and ask him what he suggests if that's your price range. If his S480 is as good as a "Real one" He may suggest that. Once you max out the cheap S480, IMO its better to go with twins. Cheaper and performs better per pound. As mentioned above you really need to step up to the BIG singles if you want performance similar to Twins. On3 makes some GT55 clones that look really promising for under a $950. Oddly enough I don't see them used much or tested much. If you'd be happy with a true 1000 @ the wheels, I'd go with the S485 over the S488 personally.

I defiantly wouldn't' go taller than a 3.50. I doubt the converter will be happy with that even. Id look at a 9.5 PTC converter and tell them you want it loose! They always spec mine too tight, every time I loosened it up I picked up. Im at a 17-0 stator now and its still too tight! But I was likely only making 900ish. (they started me at a 15). I started with a 3.10 gear. Then 3.25, Then 3.64. Picked up big each time. Little looser on the converter and a 3.73 or so would be about perfect for a street/Strip 8.50 small bore car at about 160 IMO.

Nothing wrong with a 243's by any means. IMO they sell for more than they are worth because everyone thinks they are "magic". So you can basically sell the 243's and build a set of 706's that outperform them and have $ left over. The ports on either head will both flow plenty for a cam only 5.3 at 7k. The major difference is the added compression from the baby head.

I wouldn't bother sinking money in to CNC fancy port jobs or removing deck surface form a factory head though personally. Better off selling the 243 and getting a set of as cast TFS 220 or similar.

 

That was one of the records I was looking for! right at 1200 hp by weight/trap... Didn't the turbo shell out after or during that pass? Was that on an LS3?

 

Ya not sure how much further I want to mess with small bore stuff, even though its been fun for a long time. I put together a forged 6.0 with decent heads/higher compression and it makes ~150hp more at the same boost, spools faster, and has way more torque than my SBE 5.3. Thats to be expected of course, but it makes me want to look further into a larger engine and larger twins.

Charge temps should indeed drop as turbo size goes up. I tried a 78, 80, and 94 without an IC, the single 78 would max out the sensor in a quick pull, the 94 never maxed it out. I dont worry about turbo size as I dont have a brake to worry about, two step spools everything!

I've never had any issues with the VSR units, and the ebay unit seemed fine for a good while. However, the ebay shaft eventually got really loose (wheel could hit housing) and starting leaking oil. I never used oil restrictors on journal bearing stuff. I can't complain too much as it lasted long enough and I gave it hell for the price, goes on the shelf as a mockup turbo and a lesson.

 

yep ls3 and it made a few more passes then did all of drag week and on the last day I really wanted a 7 so I put 65psi of dome pressure on it lol and it made it 1200 feet then let the smoke out in spectacular fashion lol still went 8.07 also this was the og vs80 with the red wheel I’ve herd the newer ones are better

 

LOL Nice! What boost did you typically run before that moment? To be fair I've had issues with genuine Borg units as well, none of them are indestructible.
My old On3 88/84 kept falling off up top so I deleted the wastegate and she lived awhile, maxed out my MAP and kept riding

 

it made 25-26psi every pass without problems on the final pass it peaked at 28.1psi and fell off after that

 

So i think ive came to a decision on a few things.. gonna keep the 3.50 gears I got, leave the 243s untouched (might find some 706s), gonna go with the summit stage 2 boost cam instead of the ss2, vsr billet 85 is gonna be the turbo im going with and ill be shifting at at least 7k...

 

Sorry to bring up an old thread. Slow Sedan do you have an Instagram or Facebook. I wanna pick your brain if you don't mind. I just made an account here and have to wait 30 days to pm 😿

 

What trunion kit do you use?
There's several different ones out there and they all seem to have someone who's had an issue.

 

There's pretty good reasoning behind shifting above 7k. With stock rods you generally want to keep the "shift drop" at or above peak torque. It will also play a big role in how your converter is specd. My 5.3 peaked around 6400 and i shifted at 7500, with the right converter it fell back to 6500 and lived a long non rod bending life above 30 psi.

 

Sorry I'm not on there. Can you create a thread?

I leave a lot of them stock, but the Comp ones seem to work perfectly fine as well. Some Comp sets I installed are going on 10 years old without issue.

 

Man that was exciting just hearing all those RPMs & boost! Haven’t figured out blow thru yet but just got a new car that will be FI!

 

My tuner (Jon Capizzi) told me to shift my current combo (SBE LM7, his cam) + S485 (his old turbo) at 7600+. Easier on the rods and it will make power up there.