Trying to buy a turbo and I cant decide between s475 or a gt42. Help please. It's for a junkyard 5.3 build

 

Billet 7875 is the go to JY 5.3 turbo

 

VS Racing has a 1.10 T4 S475 clone for like $420.

 

7875 OR BILLET 7875. the cast wheel 7875 sounds better if that makes any difference to you.

 

I had a 78/75 on my 6.0 and it choked out around 15 lb due to back pressure. So then I had to re do my hotside to fit the t6 turbo since the proper way to do it is to have the hotside completely divided. Wish I would have started with the t6 s475 for $400 then you can bolt on any s400 chassis turbo when plans change.

 

You have a 6.0....... He has a 5.3. Not quite the same. My buddy has a T6 on his 5.3 and he hates it. He had a bigger motor, hurt it and stuck a 5.3 in, takes way too long to spool. So the advice of using a 7875 on a 5.3 is good, sound advice. Now if he had a 6.0, the recommendation would be different.

 

Bet he didn’t divide his hotside.... read the thread when yenkomike switched from an s480 83x75 to an s 480 96x88 absolutely no difference in spool if not better.... it would make no difference with a 5.3 fully divided 2-1/4 the whole way to the flange.... not saying the 78/75 is a bad choice but when it’s time to turn up the boost the small hotside is a restriction how ever way you look at it.... you will be leaps and bounds ahead starting with a t6 flange turbo.... if you have room and depending on goals

 

I personally have owned afew different turbos all on the same turbo kit. To start with i had a 6.2 so ive stayed out of this so far but im throwing my 2 cents in here. My first turbo was a 7665 and was a torque monster and over 5000 rpm a total face plant. Made 546rwhp at 5200rpm and almost 700 ft pds of torque at 2800rpm. Car was a stupid burn out machine but that wasnt what i wanted so Then i went to a 7875 cast and it was better. Made 668rwhp and 680trq on like 18 pounds but it got damage by a dod lifter after like three months. Then i got caught up wanting something that sounded scary so i bought a gt45 88mm. Ohhh i got an 88mm turbo. It spooled slower and never really felt more powerful then the 7875 and it **** itself after just a few weeks. I broke down and bought a billet s480 96mm turbine 1.25 ar t4. Holy **** *****. Car made 770rwhp on 10 pounds of boost and all was right. I didnt have to be up on the wheel so much and it was absolutely amazing to drive. Later i added a second pump and turned it to 18 pounds no dyno then but it was freaking scary fast in mexico. Boost is addictive. Plan for far more power then you initially want. I could have bought the s480 at the beginning but i was following trends and low price. The forced inductions s480 was worth every penny. Now in all tranparency i did change other things at times two like when the 7875 got damage i went from an l99 to lsx376 b8 so dropped compression a whole point and it had a na cam i bought used. So the gt45 had way to much cam in it. When i went to the s480 i went to a tick stage 2 turbo cam so that most likely helped too. I went from 3 to 4 inch downpipe at the s480 also. I guess what im pushing more then anything is to make a goal and build a combo to reach that goal. All parts need to work together to make a badass engine. Id still suggest building for an s400 frame turbo because you would be able to fit just about small to mid frame turbo on the same kit then and it would be mostly bolt on. But like everyone here that is only my opinion.

 

Thanks for this info! Would be great to see several of the most common turbos overlayed on graphs so we could easily see where we want to be curve wise.

 

It really would help if you would elaborate on what you are trying to do. Being you only posted once and havent responded, I'd imagine this is this a one post wonder.