70mm Z71 - Stage II

After a year of testing out the truck and about 15k miles w the turbo, I’ve decided to keep stepping toward my original goal of this project.

I’ve been cruising around at 8psi and it’s been flawless. Truck runs great and never a real issue. It’s quick and keeps me just ahead or just behind most cars I run into. Which is that low 13 et or low 100s trap. I only made one pass with it at 8 and went a 13.6 at 101. I dynoed at two local shops.

Turbo Civ Dyno = 416 hp and 444 tq

New Era Performance = 402 hp and 460 tq

Average them out and it’s a pretty solid number. But it’s not high enough for bragging rights and enough to pull past 90% of the cars I’ve raced.

Yesterday I put in a fully built R&R Racing Transmission 4L70E transmission with all the goodies along w a Yank Converters TT3000 stall. The truck drives good and I can def feel the stall. W a quick re tune for lockup, shift points and torque management. It will be great.

Last week I put a 3 inch electric cut out right at the down pipe, exiting the exhaust next to the pass front tire and took it for a rip. It sounds nasty but over boosts because of the lack of back pressure. It climbed to 11psi before I was WOT. Which was pretty scary. I need some 60lb injectors before trying to make more power, so I ordered some up from fiveomotorsports. They should be here this week.

So when they come in, I’ll go get a re tune with the new injectors, trans, converter all set to 8 psi. Then I’ll open the cut out on the dyno and see how much boost it will wanna make. I’m hoping it will stay at 11 so when I wanna crush it’s just a flip of the switch and lean on it.

This stage II build will not get me my goal of 500 wheel. But it won’t leave me stranded on the road with a blown trans. The converter won’t make more power but it will help w et and light to light action.

Stage III prolly won’t come till nest year.

To Victory!

Results are on pg 3

Whoa, this is wild! you should put the edelbrock supercharger on here too see what happens.

I should leave my trailer at your house just in case, lol.

i know you have a cutout, but you could also look into a boost activated cutout.

basically, you just buy a 60mm ebay wastegate with a super weak spring and weld it to your exhaust (on like a Y) when you hit a certain amount of boost -say 4psi- it will open and will pretty much be the same as your cutout, minus the switches and minus the noise. and won’t change your exhaust tone cruising.

just a suggestion.

Nice, what made you go with R&R?

:tup: interested to see how the tranny does it would be cool to have a local person build 4l60es

Stall should make this thing a lot quicker

wtf

isnt that what a wastegate is… and i already have one one the charge pipe. Its a percision unit and works great with the cutout closed. my exhaust system matches the spring psi chart to the pound of boost. its awesome. the chart said 5, i show 5, chart shows 8 i show 8. I like that I can match each spring. I think you were trying to say is add another gate for when the cutout is open to keep it from over boosting.

when the cutout is open its makes more PSI, with the additional gate it might control it.

exhaust w gate 1w 8lb spring = 8 psi
cutout w gate 1w 8lb spring and gate 2 w say… 10 lb spring = might hold it to 10 psi with the cut out open.

Thats kinda what I am thinking about doing. So with the cutout closed, its cruising around w 8psi. when i wanna race, open it and the 2nd gate will kick once the manifold sees “10” psi and open. assisting the 1st gate and controlling the boost. before I buy another gate, i wanna see how much boost it will actually make as is. If I got WOT and it goes above 11 or 12, ill make some changes. It would be a low boost high boost switch.

OR

add a second gate and put both springs to 10 psi. they might hold it to the desired amount with the cutout open or closed.

r and d will have to be done.

Kevin and team are the best around for trannys. Ask all the fast cars whos trans they are running. They built CHODA’s and FourEyed’s trans. I trust him.

Hes just over an hour south, in Olean NY. Its worth the hour drive to see him work his magic in front of you and explain what he is doing, what each part does, why he does certain stuff. The stall should make a good dif, i wanted to launch it last night but had the prego wifey w me. If it dries up by the time I leave work, ill let it eat from a dig. track times will be the true indicator though

Thanks everyone

Yea I spoke with him before about a TH350 when I pick up another car over winter I will be in touch with him.

I was hopeful to see a good 4l60e builder around here since finding a decent builder can be hard a lot of hit and miss builds.

I’ll have to check them out.

This thing will be so nasty from a dig on the street. :tup:

Awesome! 12’s on the way!!!

Sorry what I was saying was a boost actuated cutout for the exhaust system unrelated to the actual turbokit itself.

What size gate do you have on there now ? A larger one will probably help boost creep (I think) . Or just a spring closer to whatever its going up to. It’ll still work while the cutout is closed

I hear ya, I think it would be the same as another gate w a higher spring in it to hold a high boost psi or a same spring to hold it constant.

39mm percision I believe

I love everything you are doing to this truck.

4.8?

How much do you have into this thing? Hmmmm…Can it still tow a boat reliably?

5.3. W all the mods it’s gotta be around 8gs. Boat is no prob, I towed a full size truck on my car trailer and it didn’t go into boost unless I wanted it to. It drives stock until u lean on it

Love this build…truck must sound awesome

Would having afm cause issues with this?

check it out sometime. ill have to come to a tea leaf meet soon

no. I had afm for the last year. it worked and i got 21.5 mpg going from here to roch with the cruise on 65mph and 4 people in the truck. I just tuned it off because of the annoying drone and where/how i drive the truck. it would going into v4 mode around town and because of the exhaust I have it would drone a little bit. Most people wouldnt notice it, but i did. Now its super quiet, drives like a champ, and i still get great mileage.

On sat I went to New Era for the open house. with 4 people and doing 70 msot the way and a couple times up to 85, i averaged 17.5 there.
Mike took the v4 off.
Coming home I did 70 and got 17.4.

its rock solid and I am very happy with it

Hit 81mph specifically, cough cough.