Turbo for mild 408?

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Mean416

Mean416

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So...I happen to have a spare 408 lying around. And, I happen to have a spare b body lying around that needs a small block. I happened to be daydreaming about putting a turbo on said 408. I happened to see some popular videos on YouTube regarding cheap eBay gt45's making up to 800hp, and it got me to thinking about what turbo might work for my 408 in a b body?

Seriously though the question I'm getting at, is, would a gt45 be ok for a low rpm mild 408 or should I step up to a larger unit? Would back pressure be a problem if I kept it under 5500?
 
Yeah that would work. As long as you have the exhaust free flowing and a straight through muffler I wouldn't worry about back pressure. Think most gt45 are 68 or 70mm right? Well can always run one and upgrade later.
 
Depends on your goals. A gt45 might get you 800 at the crank with decent heads and the right cam. However, you’ve got the cubes to spool a larger turbo and Chinese S475’s have dropped to around $400. Those will make 800 much easier. Use a 2 or 2-1/4” split hot side for fast spool.
 
My goals would be to build a mild mannered but fast street car. I don't have an aftermarket block so I think anything over 600 FW hp starts to be questionable. However at 408" I do worry about back pressure causing damage to either engine or turbo with the gt45 knockoffs.

Feedback appreciated. At this point I'm kinda daydreaming but I could also see myself going for it.
 
Mean416 said:
My goals would be to build a mild mannered but fast street car. I don't have an aftermarket block so I think anything over 600 FW hp starts to be questionable. However at 408" I do worry about back pressure causing damage to either engine or turbo with the gt45 knockoffs.

Feedback appreciated. At this point I'm kinda daydreaming but I could also see myself going for it.
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My preference would still the S475. A 7875 would be a bit small on the exhaust side, but would work okay. A gt45 would come on pretty fast, but likely be exhaust limited by 5k.
 
Use an s480 and never think twice about it.
 
TT5.9mag said:
I’m not sure cheap is the way to go here. I’ve looked at a few of the eBay gt45s and I wouldn’t run one. That being said I have had great luck with the vsr7875s so I’ll recommend this………
VSR 80mm Billet T4 96×88 Turbine wheel 1.25 – VSRacing
I like the t4 option and Viren is a great guy to deal with.
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Ohh....

Cheap is the only way to go! If it weren't for the complexity and overkill I'd just do twin gt45 knockoffs.

Just to clarify. Cheap is the only way this can happen with my current budget constraints.

I'm still thinking about the 45. If I could get say 600 hp, all in, by 5000 rpm, I'd say it's still a damn fast fun car
 
Mean416 said:
Ohh....

Cheap is the only way to go! If it weren't for the complexity and overkill I'd just do twin gt45 knockoffs.


Just to clarify. Cheap is the only way this can happen with my current budget constraints.

I'm still thinking about the 45. If I could get say 600 hp, all in, by 5000 rpm, I'd say it's still a damn fast fun car
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It will be damn fast but for how long?
 
I know lots of guys have gone fast and made big power with em. Hell I have too, I used an eBay gt35 on my Honda v6 in the beginning. But I’ll tell you this, every single person I know that’s done an eBay turbo, EVERY ONE, has upgraded it shortly after putting it in service. Because they don’t last, start to wobble or tear into the compressor housing and hopefully you catch it early and the above doesn’t happen. Buy once cry once.
 
And for your money you get hp. The garret gtx3582 I replaced my eBay gt35 with made 75 more hp at the same boost and it was identical spec wise. Just dual ball bearing.
 
Just trying to show you what happens and maybe save you a bit of money. Ive been there, done it, blew it up, rebuilt it, and blew up again. Hopefully you can learn from my mistakes. You do you.
 
TT5.9mag said:
Just trying to show you what happens and maybe save you a bit of money. Ive been there, done it, blew it up, rebuilt it, and blew up again. Hopefully you can learn from my mistakes. You do you.
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I have great respect for you and others on here who have executed real builds.

What was at fault with your setup? Was it specifically turbo related?
 
Mean416 said:
Ohh....

Cheap is the only way to go! If it weren't for the complexity and overkill I'd just do twin gt45 knockoffs.

Just to clarify. Cheap is the only way this can happen with my current budget constraints.

I'm still thinking about the 45. If I could get say 600 hp, all in, by 5000 rpm, I'd say it's still a damn fast fun car
Click to expand...

If you don’t mind it nosing over at 5k then a gt45 would be perfect. Full boost likely below 2,500.
 
TT5.9mag said:
Just trying to show you what happens and maybe save you a bit of money. Ive been there, done it, blew it up, rebuilt it, and blew up again. Hopefully you can learn from my mistakes. You do you.
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I hauled my Cuda to my Dad's in Oklahoma earlier this year when I accepted a transfer TX. That turned into a **** show and, believe it or not, it benefits me more to stay working in CA (cost of living allowance and the higher occurrence of wildfires). I will be pulling the engine and bringing it back to CA. My Dad is going to get the TKO and the car will go into his buddies Mopar resto shop for bodywork and a cage next summer.
I am going to take off the Procharger and make use of the twin turbo headers I just acquired. It is coming with two Wuhan Whistlers but I have been researching and now want to save up for some legit turbos.
I would love to pick your brain and maybe meet up to discuss timing, timing control, fuel, wastegates, boost controllers, intercooling, etc. I like where the engines at power wise but want to switch up to turbos. I would love to learn from any mistakes and take some advice. I would love to get v2 on the dyno at Brian's in Indio and compare it to the dyno numbers from when it was first put together with the D1-SC.
 
go-fish said:
I hauled my Cuda to my Dad's in Oklahoma earlier this year when I accepted a transfer TX. That turned into a **** show and, believe it or not, it benefits me more to stay working in CA (cost of living allowance and the higher occurrence of wildfires). I will be pulling the engine and bringing it back to CA. My Dad is going to get the TKO and the car will go into his buddies Mopar resto shop for bodywork and a cage next summer.
I am going to take off the Procharger and make use of the twin turbo headers I just acquired. It is coming with two Wuhan Whistlers but I have been researching and now want to save up for some legit turbos.
I would love to pick your brain and maybe meet up to discuss timing, timing control, fuel, wastegates, boost controllers, intercooling, etc. I like where the engines at power wise but want to switch up to turbos. I would love to learn from any mistakes and take some advice. I would love to get v2 on the dyno at Brian's in Indio and compare it to the dyno numbers from when it was first put together with the D1-SC.
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Anytime. If your out this way (inland empire) just say the word. I’ll be on the dyno at westech on the 29th with my twin turbo big block of you wanna come see it. You’re in SD so if I get down that way I’ll let you know.
 
Mean416 said:
I have great respect for you and others on here who have executed real builds.

What was at fault with your setup? Was it specifically turbo related?
Click to expand...
Which set up? I have 3 turbo cars and one turbo boat. My dart has a 5.9magnum with twins, my falcon has a Honda v6 with a single, my truck has a big block with a huge single, and my boat has a big, big block with twins. On the falcon with the gt35 that I switched out, a good friend of mine (and very well known import tuner) told me to junk the China gt35 and get the garret and I’d make a bunch more power. When I took the China turbo off the compressor wheel was rubbing on the compressor housing and chewing in to it, sending very small bits of aluminum through the engine. I’m so glad I took his advice, not just for the power gain but because I caught it in time before I destroyed another engine. That time it just got bearings and rings and a quicky hone.
 
TT5.9mag said:
Anytime. If your out this way (inland empire) just say the word. I’ll be on the dyno at westech on the 29th with my twin turbo big block of you wanna come see it. You’re in SD so if I get down that way I’ll let you know.
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I will more than likely be on another fire assignment by the as all of California is supposed to heat up and lose the monsoonal weather pattern we're having right now. My engine is on top of the strike team rotation. If we do the full 14 days allowed on assignment we get 3 days paid R&R and I was going to combine some leave with that and go to Oklahoma and get the Cuda engine. If it all works out I would love to see it and learn more about turbocharging. If not, we can meet up whenever is convenient. I get up the 15 often.
 
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