Rob Raymer 2

Been a little while since I've started a new project, but the time is finally here!!! The car everything will be going in, is my '78 Trans Am (previously a 700+rwhp Twin Turbo LS6....about 5-6 years ago)






This time the build-up will begin with, let's say, an "expendable" 30k mile stock iron block 5.3 with stock alum heads. Which is also why I'm very open to experimentation with various ideas.

The goal will be to build a fast, dependable, daily driver (realizing that "dependable" would likely mean a forged engine later), and not spend a fortune. With that in mind, here is what I have so far:

*I'm leaning toward a big rear mount, but it's not set in stone.

These parts are set in stone: 400 Turbo Trans, 3500 Stall, 9in Rear with 3.25 Gears, 28" Tall Tires.

Stock 30k mile 5.3 iron block engine
Stock Alum heads with Patriot Gold Springs
Stock Computer w/3 Bar MAP
Stock LS1 Intake & TB - open to suggestions, but leaning toward Vic Jr, stock TB, and Intake Elbow again.
Stock Cam - Looking for your input here - I like "lope", so thinking about a custom cam in the 230dur .550lift 115LS range. Though an LS9 cam did cross my mind.
ARP rod bolts, head bolts and LS9 gaskets (or custom Cometics) likely.
Don't plan on porting the heads, but open for discussion.
Minimum of 83lb Injectors with 1:1 Regulator
E85 - That's the plan, but again....open to discuss.
Large Rear Mount Turbo (divided housing) - Would like a 1200-1500HP capable turbo. Chime in!!!!
Or Twins on the rear???
Boost Spool Valve - Thanks Zombie for all the info you posted!
Self-contained oiling system
FMIC
**I'm even considering compound boost options.

Looking for 650-700rwhp on "street" mode, and 800+rwhp on "kill". The car weighed 3800lbs with the alum 5.7 NA. So I'm guessing it will easily break 4000lbs with an iron block, rear mount, A/C, etc. So it's gonna need to make at least this much power to even be considered remotely fast nowadays. Cuz some of you guys are stupid fast!!

Anyway, anxious to hear what everyone thinks. Build begins next week and I want to have it finished in time to take it to the track in about 5 weeks!

Thanks in advance!!

2nd Gen Fl 'bird

iTrader: (13)

Subscribing. I have an '81 TA with 5.3 going in so, I'm on board. Nice clean car. Love the "turbo hood" transplant.

charlie_gonzales

iTrader: (12)

When you mentioned compound boost do you mean small turbo and a big turbo or supercharger and turbo...some people like it some don't...its definitely interesting to me like the hellraiser kits from hellion for the 03-04 cobras(eaton and turbo)

1CAMWNDR

iTrader: (21)

I'd like to see at least a valve job on the heads. Also a 4150 4BBL throttle body instead of the elbow job. A 230° cam is kinda big for a 5.3 isn't it? I'd use a 220° to 224° intake lobe and the exhaust would depend on projected back pressure. I like the 115° LSA. Of course this is gonna be a rear mount----I don't know if that changes cam selection or not.

Cool project.

Rob Raymer 2

Supercharger and Turbo.

With only 30k on the 5.3, doubt the heads will actually need anything. Plus, if I do a valvejob, I'll definitely have em ported first. And if I hadn't already made 800rwhp with a 130k mile set of heads on an LS1, I might would consider it.

Now that's a thought!!


Yea...I totally agree. I was basically "rounding up", trying to keep it simple. And I expect backpressure should be pretty low with a big turbo. But won't know for sure til I check it....

Thank you!!

charlie_gonzales

iTrader: (12)

I'm feeling you on the supercharger and turbo I thought about adding a turbo to my truck(Joe gibbs silverado- rcsb 5.3 with a raddix blower)...similar setup to yours...so I'm looking forward to see the turn out and what parts you use

retardedpenguin

iTrader: (2)

That's awesome, about to start my build with a front mount LQ4 in my 80 Special Edition Trans Am.. What motor mounts did you use?

jus1975

I would like to follow this thread. Is there a reason you went with the 5.3 and not a 6.0.

Rob Raymer 2

Yep. 5.3's are CHEAP!

compgto

iTrader: (7)

What happened to your old setup?

compgto

iTrader: (7)

Do you plan to run the tips like they originally were? If so I wouldnt do a big rear mount. Of course, original went out the window with the motor & 4.9 Turbo hood . Gonna be sick man I'd like to do the same with my dad's '78.

LTXBOI

iTrader: (2)

He must wants to desintigrate.....or go to outer space in a fire hawk....Is there
even a engine builder,that can pull that off...Oh yes there is Nelson racing engines.

Rob Raymer 2

I actually had a set of custom polished stainless "original type" tips made, but dual 3":



I plan to use them still, but as dump tubes for the wastegate(s). Probably going to do what I did on my old Formula....run dual wastegates, with one conrolling boost and the other one basically as a safety device with an 18-20lb spring in it (should the main WG ever fail). At least then they're functional, and not just dummy pipes.




Actually, it ended up going in my old Formula. Like a tard, I ran the stock engine low on oil and hurt a bearing. It was my DD and I couldn't afford to fix it at the time. The T/A was just sitting, so I threw the engine in the Formula. And later, built the rear mount for it.

compgto

iTrader: (7)

The Formula set up is badass, makes me want a rear mount!

'Trust'

iTrader: (24)

I'd think twins in the rear would be more efficient than a large single, but that is just my inclination, could be way off. Formy setup looks cool, any numbers on it?

Rob Raymer 2

Thanks!

With an 85mm MAF tune, through a stock 4L60E trans, 687rwhp/761rwtq.

Vid here: Rear Mount Turbo LS6 Formula Dyno Video

Rob Raymer 2

BTW, absolutely LOVE your Viper!! I had a '98 GTS myself and it was one of the best cars I've ever owned. Hope to be able to afford one again someday.....COME ON POWERBALL!!!!!

1CAMWNDR

iTrader: (21)

Love the placement on that rear mount also.

Rob Raymer 2

Thanks! Cuz there definitely wasn't anything easy about putting it there!! But let me say this, on the street, this was the best sounding turbo car I've ever owned! It sounded like some crazy, bada$$ jet plane. Which is why I'm so motivated to rear mount the T/A now.

1CAMWNDR

iTrader: (21)

The only thing about a rear mount that concerns me is running the charge pipe back up to the engine compartment, and finding a place for the filter to be not quite so exposed. Hmmm, 400" motor, rear 85-88mm turbo with a divided housing and a spool valve in that location. Badass.