I am in the planning/buying parts phase of a BBC build. It is going into a 1970 Pontiac Lemans, and I already have a 4L80 with manual valve body and billet triple disc converter being built, also a ford 9" coming. The engine is a BBC, will be .060 over, forged bottom end and compression set to 9.0:1. Heads are going to be Brodix BB-2-Plus top end kit and QFT 850 blow thru carb. My goals for the engine are 900hp, and must run on pump gas. I would love to get the car into the 9's eventually, and still be able to run on the street. I would like the simplicity of a single, only for the plumbing, but if there are other opinions I would love to hear them. So my questions are:

1. What would be a good turbo? (I don't know enough about turbos to make a decision)
2. I am looking at the FITECH dual in tank pump https://fitechefi.com/products/40020/, and aeromotive 13301 regualtor. Enough fuel with -6 line?
3. I am also looking at this cam- https://www.summitracing.com/parts/cca-11-414-8/overview/make/chevrolet

Thoughts? I am new to turbocharged engines, and everywhere I look, it is some self proclaimed expert saying one thing or another, or a business owner telling me to buy 10K worth of parts from him after talking for 12 seconds...... I need help!

 

I think with that many cubes and good heads you would be better off with twins than a single. A single big enough is going to be huge and expensive. I don't think plumbing is any harder, its just different. I would lean toward twin s364 or if you can package them a pair of s475 T4 87mm. There are more experienced members here who could make some good recommendations though, and I am only really familiar with the BW line.

I like my FiTech, there are a lot of people on this forum who like them as well, there are several threads on it. -6 will be ok with EFI, but you would future proof yourself by going a little bigger, it wont be long before the itch to turn up the boost comes.

You probably don't need that much of a split on the camshaft with a turbo. That looks more like a supercharger cam to me.

 

I like where your head is, and s475's can be had pretty cheap. I can tig pretty good, so piping isn't going to be an issue. One suggestion was a Borg 488, which is a HUGE charger.

So t4 foot 475 and 87mm turbine, what a/r would you suggest?

Another camshaft option is a lil john custom grind, which I have talked to guys that wished they had went to him first.

Do you have only a fitech pump, or efi as well?

 

The S400 series chargers are the same size really. An S475 is the same size as an S488. The T4 475 has a smaller 83/75mm exh wheel on it, not the 87mm. It has a slightly smaller exhaust side but the compressor housings are massive and the same size.

I like simple and find single setups to be easier for the most part. I'd skip the S400 frame stuff and jump in to the GT55 based 103mm exh wheel clones. On3 sells a 94mm and a 107mm very reasonably. ($950)And these have the SS Vband exhaust housings that are a TON lighter weight.

That said you have pretty darn modest goals for a big block setup with a nice top end. I'd go with the cheaper cast wheel 94mm. Plenty of turbo for your goals and MUCH less weight with this single.

For reference I'm going 9 flat with a 4.8 liter and it's VERY mild. OEM heads tiny cam etc.

https://www.on3performance.com/prod...ger-t6-stainless-v-band-exhaust-housing-copy/

 

Yeah, pump gas and 9's are the goal. It's only going to have a 10 point cage, and there is potential to outrun the cage with 500" and lots of boost. I want to have the option to really turn it up, later on. I'd like to build it once....

 

Call Lil John. He will point you in the right direction on the turbo selection as well as the camshaft. Very helpful and knowledgeable guy, although a bit curt at times. He probably has the turbo you need on the shelf. You usually have to call and leave a message for him but he WILL get back with you.

 

Talked to him a couple of days ago. Custom grind camshaft and a big s400 turbo was his recommendation. He knows his stuff for sure.

 

Your longblock with an S488 at 14psi is going to make 900 at 4K rpm's lol.

 

How do you figure that number? I'm not trying to sharpshoot, I don't know much about turbos and gas engines....

 

I'd guess your longblock is going to be in the 500+ range NA. Add 14 lbs and double that HP number. The saying 'there is no replacement for displacement' is increased exponentially when boost is added.

We make 800 on a 414ci SBC at 14 lbs with a mildish cam and extremely safe tune. You're added cubes aren't going to make less than we are.