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Pulled the trigger: Mild H/C to street turbo set up (3rd gen) - 6.7@106.8 mph
Updated from inquiry thread to build thread. Thanks for everyone's previous input.
Time to update the old mullet mobile. Was going to look into a quality top end(AI, custom cam, Fast, etc) but hp/$ has me leaning towards turbo.
Current set up:
2001 LS1(under 30K miles)
Patriot stage 2 heads (Approx 11.1 compression)
TR 224/224 .563/.563 114
LS6 intake manifold
Pushing a little over 400rwhp/400rwtq
Bought a local(non-sponsor) turbo kit:
76/65 turbo (.96 AR)
3" Stainless Steel Downpipe
2.5" Cross Pipe
60mm Vband Wastegate(skipped for a Tial 44mm)
50MM BOV
Intercooler 31"x12"x4"
Will install(per my research):
Currently running walbro 255 in stock plastic LS1 tank, fuel line, return, fuel rails, regulator, etc
Will add secondary Walbro 450 in off a hobb switch
80 lbs injectors
GM 2 bar map sensor(thanks Game for input)
Skipping Chinese Headstuds and LS9 headgasket due to low boost. Save them for my gen 4 build.
Goal: Not looking to set records, just a fun street car with instant boost, keep revs under 6500, 500-550rwhp reliably with E85, max boost of 12-14 psi.
12/21/17 Added time slip at page 8
Last edited by CyberGrey Z28; 04-17-2018 at 02:15 AM.
Should be a peppy setup..I think you might hit more than that for power goals.Id say just dump the 255 intank pump and put the 450 in there now.I hit 600whp and my 255 pump couldnt keep up at 12psi boost on 94 pumpgas.
Should be a peppy setup..I think you might hit more than that for power goals.Id say just dump the 255 intank pump and put the 450 in there now.I hit 600whp and my 255 pump couldnt keep up at 12psi boost on 94 pumpgas.
What gears are you running in the back?
That was my initial plan but read the 450 will over power the stock regulator at idle. I'm going to experiment with the 450 as a secondary.
I'm currently on 3.73 gears 26inch tire. Will probably go 28 inch if I stay 6 speed.
Looking good! Don't see the paramiter bolt valve covers much at all!
I'm returning mine to the front timing cover.
Out of curiousity, why did you go with the 76/65 over the 78/75.
Are you drilling or welding the return bung on the timing cover?
Picked the 76/65 because I wanted instant spool from the smaller turbo for a 6 speed street car.
Can't run at the track anymore without a rollbar so I decided to have some fun with it before building a forged engine, big turbo, proper fuel system, roll cage, and built 4l80.
Curious to see how much that 78 does on your set-up? Think it'll do 750rwhp?
Are you drilling or welding the return bung on the timing cover?
Picked the 76/65 because I wanted instant spool from the smaller turbo for a 6 speed street car.
Can't run at the track anymore without a rollbar so I decided to have some fun with it before building a forged engine, big turbo, proper fuel system, roll cage, and built 4l80.
Curious to see how much that 78 does on your set-up? Think it'll do 750rwhp?
I'm welding mine into the front cover!
I know it will, buddy did 750/850 with a z06 cam and stock 862 heads, sbe 5.3 in a full size cheby thrue an 80e, with the cast wheel 78/75, I've got the billet. From what I've read people who did the swap from the 76 to the 78 said they couldn't tell a difference in spool so I was curious lol. I almost did the 77/83 but was worried it might be a touch laggy so I went this route
Welded the return line to the pass. side of the timing cover on a 45* angle to easily gravity drain.Run the 450 pump and an aftermarket regulator to the stock rail.Wont stress the factory stuff at that point and have very stable fuel.Your hotside is similar to mine.Tight fit but works and I didnt relocate any of my drive accessories.I still have no idea how much power my setup makes lol. At this point it doesnt really matter as long as the car runs good and pulls hard.I need a retune but im considering going with a billet 78mm.Spool time doesnt seem laggy at all unless i dial the boost down.15psi..lights up beautifully lol
^^^Good info on the FPR and return. I saw your vids, sounds amazing
Made some progress. Practiced drilling an oil pan but resulting shavings made me uncomfortable. Instead I drilled and tapped the front cover.
Next I researched crankcase venting and decided on dual 10an lines from each valve cover to a vented catch can. Got a little creative on the valve cover 10an adapters.
Did the same to the driver's side PCV fitting. Using 10an braided/nylon lines and ebay baffled catch can.
Finally, been learning tuning basics "Master EFI Tuner" by Dan Maslic. Will post up for help when I fire it up.
Coming along well and very clean setup. Im thinking of switching to Vsracing 77/83 to help reduce backpressure issues Im experiencing with my exhaust setup. I didnt want boost coming in at a lower rpm had I gone with a 76mm turbo on the street I feel I get a much smoother cruise off boost for city driving and its "stealthy" not having my bov go off with every shift. I build boost around 2500-3k and if I hammer it..the boost kicks in fairly progressive and not a hard hit to spin too harshly. Im curious to see how your car drives and where your boost starts to come on. What are you running for an ecu/tuning?
I have hp tuners pro and ngk/ntk wide band. Hoping my mild set-up will make it easier to learn the basics.
Can't run at the track the car sits, so I'm just going to drive it around town/meets/Mexico runs. I'm thinking the higher compression and boost under 15 psi will make it a fun street car. Didn't think about the bov sounding off so much til now lol
What back pressure issues are you seeing with the 78mm?
The issue is trying o get the exhaust flow out...and my car currently has hi-flow cats but it restricts the motor uptop in the rpm range.Boost tapers off after 5400rpm. You have a smaller 65mm and even with a .96ar you can turn the boost up as much as possible but the combo isnt going to be efficient. You will have instant spool sure...rev limit to 6k. 550rwhp should be close but there is lots being left on the table. What made you decide on E85?
I see. What about electric cut-outs before the the cats?
I have an E cut-out bypassing my exhaust with proven hp on the dyno. I can only imagine the hp gains will be higher with boost.
I'll experiment with the smaller turbo while I work on the forged LS1 sitting in my driveway with spun bearings. Once I get bored I'll swap it in along with a larger turbo and th400
Reason for E85 is the knock resistance specially given the higher than ideal compression ratio. Also, it's considerably cheaper than the crappy 91 we have here in California.
11-05-2016, 01:54 PM
Pulled the trigger: Mild H/C to street turbo set up (3rd gen) - 6.7@106.8 mph 
