High Comp 120cc Build

samIam

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Soooo...the time has come to buy a turbo. This last season I got to 12.05 quarter mile but have shaved 80 pounds taking out the seats I had in there from a 01 STS(I think). I will go to the track a couple times this year to see if I can get into the 11s but I'm buying the turbo this in the next few days after I do my due diligence.

My setup is...
73 500ci bored .030 over to 507ci
Forged +15 domed pistons and rods from courtney
Custom hydraulic roller cam designed by mad cadder. Specs are on this thread somewhere also.
Ported heads with raised runners.(flow numbers are further back on this thread). I'll post them when I find them.
Stage 2 or 3 rockers from Marty
Extra oil line from above pump to rear valley
Bulldog intake matched to intake
1050 dominator
Custom headers
Electric waterpump and power steering
Full interior in the 84 coupe but with NRG race seats
3.93 gears I believe
Small tire
Manual th400 without trans brake, 3500 stall
Dyno was 537tq and 534hp ran up to 6300rpm, I shift around 57/5800rpm at the track and go thru the traps around 5900rpm

I drive this a little around the city but not much as it's pretty loud. It had more miles at the track this year then city driving, did 5 trips to the track last year including one road course(won't do that again). Doing my research and talking with some people that run turbos at the track, I've come to the conclusion that I'm looking for something in the 85-88mm cold side and around 100-120mm hot side turbine. Wondering what the group is thinking of the turbo choice since turbo is new to me? I've read about as much as I can from the forum but it's all starting to run together. Hoping to stick to the budget around $1k give or take for the turbo. Thats cheap but there are some decent turbos around that price. Thanks in advance yall.
 

Darius

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Howdy SamIam,

Welcome to turbo insanity, the never ending quest for MORE. Period.

Below are four links to short videos put out by Richard Holdener. Each deals with big block Chevys but utilizing different turbocharger setups. That engine choice was obvious as it is close to our own.

When entering into this crazy turbo world questions arise about: "Just what are your goals?" "How much power do you expect to need? "Are you set on a really big single or a pair of turbos?"

Starting with your current track times (Congratulations!) getting into the 11's would only require a good tailwind. Based on your current build level your 11 second goal is easy (if the goals remain limited) or more involved (if you want really big numbers). Only two areas in your current parts list would need attention: that 1050 Dominator and your overall fuel system, about which nothing is posted. The carb will need to be setup / exchanged for blow through, and fuel needs will be set by your overall lusts.

Anyway, hopefully these short videos will provide some food for thought.








For the record my engine build is nothing compared to yours. What I have is your basic grocery-getter built to have stupid torque from 2,000 RPM to 5,000 RPM. To that end I bought a pair of used 3782 Garrett VNT turbos, the early ones with the better flowing 10 blade exhaust turbine wheels. Combined, the stock compressors will be limited in air flow to just over 1,000 HP. If they fall short, or if I become even more demented, a swap of the compressor housings, compressor wheels and respective backing plates with solve any air flow shortfall while the center sections, and hot sides, should be good to go.

Best.

bro. d
 
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samIam

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Fuel is mixed seventy five percent 93 octane and twenty five percent 110 race fuel.
Current fuel delivery is a stock 84 cadillac in tank pump that puts out 40psi to a regulator down to 6-7psi.
Head gaskets are the white ones, forget the name. Sticky stuff...I'll think of them and post them.

The 11 second thing is something I wanted to do this year before things come apart for the turbo build. I think I can get there.

The turbo goal is to race. The track has been fun and now we have started to stay the whole weekend or 3 day events at times. The goal is to have all out power that I can gradually turn up as I learn.

Thank you for the videos. I have thought about twin turbo but haven't talked to anybody that has experience with them. They sure would look nice under the hood though.
 

samIam

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After watching the videos, I'm thinking twin turbos now. Thanks D, good info there.

Looking back in this thread, I see my piston ring gap is set to .019/.020 top and .023/.024 bottom. Looking at specs, they want .006 x bore and that would put me at .0258. Think this motor might have to come all the way apart again..

..Or maybe after 3 race seasons the gap is bigger now??
 
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5one9

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What vehicle(s) do you drive?
2007 Magnum SRT8, 1957 F100
Are you still running the 0.650"/253/106+4 cam?
 
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