What makes you say that? My original VSR invoice says I paid for a billet...

 

it doesn't look like the vsracing billet 7875s I have seen. But looks like the cast deals.

 

that's the billet 7875 right off his website. Compare that to yours...

 

very interesting...I sent them an email, we'll see what they come back with.

 

First I'll confirm the turbo you showed in the pictures is a cast 7875

1) It depends what type of boost controller you want to run. If you're running no controller (spring pressure) or a standard manual controller I would suggest just running a line straight from your intake manifold/vacuum block to the lower port on the wastegate. If you're running an electronic controller, straight boost pressure (comp outlet) goes to the bottom port and regulated pressure (after the controller) goes to the top.

2) Brake booster to intake manifold doesn't need anything changed. This is where I put my vacuum block. I ran a catch can on the low side (valve cover -> catch can -> check valve -> intake manifold) and vented oil cap + vented valley cover for the high side, this way at idle you don't get any crankcase gases when you're sitting there. If you want quick and dirty just completely vent both valve covers and the valley cover, don't connect anything to the intake manifold.

3) If you're trying to do it as quickly/cheap as possible, don't do anything besides deka 80's and a 450 in the tank. The stock bucket is easy to cut open and drop a 450 in it. This is the same setup I used, at idle you might see slightly elevated fuel pressure (I saw 64psi with what was supposed to be a 58 psi/4 bar regulator) but it's fine and can easily be tuned around with the 450's even running ethanol.

Other side note - adding true flex fuel capability is well worth it and awesome to have

 

I'm late to the party here but this is cool. Your wife wrenching with you and a corvette being used as a towrig?? ?? That's what I'm talkin about! Once you get your first taste of turbo LS greatness you will be hooked for sure

 

VS Racing is sending me a billet unit, they confirmed I have a cast wheel. I'll be returning that one.

I’m starting with spring pressure, no controller, so I’ll run a line to the lower body port of the WG. Another question, how do I see what spring pressure I have in the WG and how do I measure other springs (a couple were included)? Eventually I’ll put together a small MBC (leak type)

It sounds like there’s already a check valve in the brake booster line, which is good. I’ll look into the setup you mentioned for PCV.

Deka 80s and 450s are installed already, so it sounds like I just need to fill er up with E85. I plan on using one of Matt’s canned tunes from the Sloppy Wiki, how do I go about modifying the tune for E85? I eventually plan on installing an alcohol content sensor but for now I just want to stick with one fuel and learn how to tune before going crazy with flex.

Finally, I welded in my wideband bung about 18” after the turbo. What’s the deal with the stock narrowbands and MAF? I assume the MAF will be deleted so I should run speed density, but where do the narrowband(s) get installed?

I’m a noob turbo guy so any help is appreciated.

She’s great, she puts up with my hobby (obsession) and makes good sandwiches.

 

I think you can test the wastegate springs by applying pressure to it with a spare air compressor regulator hooked up to a compressor. I believe there are videos of this out there. I just threw in the weakest spring in mine which turned out to be about 8 PSI.

I welded bungs into the stock manifolds for the narrow bands. I put them right at the collector. I've been running open loop the whole time though so I never really used the NB02s. Most people, myself included seem to ditch the MAF and run SD.

 

VSR was awesome to work with, my billet turbo will be here tomorrow and they paid for the return shipping on the cast unit. Very pleased with the service.

Regarding the NBO2 sensors - what about running E85? I'll be running that exclusively, won't the stoich in the PCM be thrown off since stoich is different between 93 and the E85?

 

Oh man, no idea on that one, hopefully someone that knows that will drop by and answer cuz I'm curious myself. After getting one turbo build under my belt so far, and with E85 showing up where I live finally, I'm ready to explore this option just like you.

Now don't quote me on this but I'd think you could just change the stoich setting in HPT itself???

 

how would you test a manual boost controller?

i used to have a sr20det and when i had one it was just screw it in more and go drive and see how much boost it made oh you want less..unscrew the head and see how much less youre making ...which is a bit mickey mouse imo.

 

I'll try to start from the top:

Just using regulated shop air and seeing when the valve starts to open will give you a pretty good idea. When it's actually in the exhaust you'll get the exhaust backpressure helping to open the gate, so the pressure you measure when it's opening on the bench tends to be slightly higher than the actual boost pressure you'll get from the spring.

I think most of Matt's tunes are actually setup for ethanol, but if they're not the biggest things to modify are the stoich ratio, cranking VE, VE table and spark table and it'll run fine.

Definteily run speed density, but the rest is up to you. I ran SD closed loop (with narrowbands) because I drove the truck year round and far distances. If ambient conditions or fuel changes enough you want the PCM to understand how it needs to correct fueling in normal low-medium load conditions so it still drives well. This is why I almost always recommend SD-closed loop for turbo LS stuff that isn't a 100% racecar. Anywhere in the manifolds or crossover pipe would work fine, the passenger bank one will obviously see exh gas from both banks but it isn't an issue. I also put an LS3 MAF in just for reference, the PCM didn't reference it at all for fueling. This isn't needed but I liked being able to see how much I was flowing for estimating power output at different boost levels.

On narrowbands with ethanol - non issue. NB oxygen sensors measure oxygen, which is directly correlated to the lambda of the exhaust gas (1.0=stoich, <1.0=rich, >1.0=lean). Even though the actual ratio of fuel vs air for stoich changes, the oxygen sensor still just outputs based on oxygen and thus correlates to lambda. Same thing goes for every oxygen sensor (widebands), they just more precisely measure the oxygen content.

 

I pulled out the old 4L60E last night. Anyone wanna buy it? Shifted perfect, 93K. Fluid came out clean and bright red (mostly all over my floor)

https://i.imgur.com/yAmlq09.jpg

https://i.imgur.com/vI01ni7.jpg

https://i.imgur.com/2dHOk72.jpg

Got the cast 7875 sent back to Viren, billet 7875 arrived quickly, cat approved

https://i.imgur.com/dokEOuo.jpg

How I felt carrying it out to the garage and installing it

https://i.imgur.com/7yQryTi.png

 

4L60E out, 4L80E ready to go in

Also finally got the Street Series Jake's Converter in, took a couple weeks to arrive.











Ordered the 4L80E yoke, new u-joints, and the rear 8.8 yoke adapter. First time messing with driveshafts, always fun to try new stuff, or so I thought until I was torching the old u-joint caps and hammering them to get them out.

 

pressing is the way to go.


re: e85 and narrowband o2's, noorj has it right. o2 sensors only detect oxygen content levels and extract the afr from that. the blend table controls what stoich value the computer is trying to achieve

glad viren sorted you out. he's been nothing but great to me and my customers

 

I have found that at least in my case, running in open loop speed density has not posed a problem with driveability. Not that I could detect at least? I turned off the closed loop functions when I was sorting out other stuff and just never turned it back on. I should now though, since other things have been sorted out, just to see!

 

Is there a way to run speed density (Fail the MAF) without the check engine light being on? I am going to run the truck with the charge piping off for the first couple runs to iron out any bugs from the new trans and rear end

 

yeah set SES disable for the maf fail, report error on first occurence

then set the maf fail high to the lowest cell on the maf freqency table, and put a value of 50 in the first 2 cells

that'll fail the maf, but keep it from stumbling upon maf fail everytime you flash

 

Cool. I am getting closer to firing this thing up. Lots of little junk left but I got the 8.8 permanently mounted and shock mounts welded on, driveshaft is finished. Still need to wire and plumb trans, finish crossover and downpipe, blah blah blah.

Been chipping away the tune every night, so far I have the 80lb injector data input and the OS flashed to a 3bar MAP system. I need to do a segment swap for the 4L80E but I'm not quite sure how to do that yet...need to do some HW

 

Crossover finished, trans plumbed to the cooler in the radiator. I ordered up an aftermarket 4L80E swap dipstick and that one doesn't fit, pretty aggravating. If I can figure out how to bend that tube without kinking it, I may be able to fire the thing up this weekend...