bigturboz28

I started the build up of my single turbo LS1 (replacing GT42 front mount with a GT45/42? VNT turbo) In addition I will implement Megasquirt on the engine controlling both Fuel and Ignition using the stock sensors with wideband feedback.

Phase A -> Prep the VNT turbo by modifying VNT control / install dual spring Patriots Gold on 317 castings and acquire MSI-V3.0 + LC1 WB.
Phase B -> Remove previous turbo set (intake piping, intercooler, turbo), and move the rad forward to make room for the bigger turbo.
Phase C -> Build new hot side and intake piping and install new heads.
Phase D -> Install MSI-V3.0 to control fuel and meth only and tune.
Phase E -> Wire up MSI-V3.0 to control ignition and tune.

Phase A
So I took apart the wastegate control and tried about 7 different springs until I found what i liked (fully open at 15psi). In addition I had to weld up a new mounting bracket for the wastegate control and reverse it's actuation direction on the turbo. As the theory states I should not need a traditional wastegate. I will adjust the springs once i know the peak boost with this one. I have already installed the patriot springs (I was getting valve float on my stock springs with previous setup) on a set of used 317. I am waiting for the head gaskets that i ordered 2 weeks ago. The MS arrived Friday, and I am pretty sure I know what has to change in the code (make the second trigger fire on both the rising and falling edge of the crank sensor).

Phase B
I removed all the previous stuff to make room. I moved the rad and condensor forward (BTW you can get about 11 inches of space using the stock rads and keeping the AC) - I am not sure if this turbo will fit, it is damn HUGE. The turbo beside it is a GT42! (don't mind my choice of intake piping, it is very easy to work with, cheap and it works).

So far Phase A and B are done. I will not get a chance to work on it next weekend, but should the following weekend. I will try to update as I go.

bigturboz28

Couple more pics...

99Z28LS1

iTrader: (4)

looks like an interesting build, i hope it all works out for you bud, i will be watching

bigturboz28

I took the heads off to install the low comp heads and found a "little" problem...
Looks like it might ending up being a VNT + Megasquirt + 402 iron....

Also on a side note: do not use the MLS gaskets with 98 heads, I have a pictures that shows the "missing" part of the casting that does not seal to the gasket.

bigturboz28

Pulled motor and tranny going to be putting in a forged 402 with a built tranny.

bigturboz28

Installed the PST driveshaft, Build T-56, LS2 402 and accessories. Here are the specs on the engine...

402 ls2 stroker with wiseco 8.8:1 pistons, hellfire rings, howard's billet steel rods, eagle crank, all arp studs and patriot stage 3 heads, the cam is a 246/240-114 comp hr grind. I also installed 96lb low-imp injectors.

I made a set of forward facing headers from my old 99 exhaust manifolds. I have finished all the hot side piping and mounted the turbo. I relocated the radiator/radiator mounting to make room for that giant fu*king turbo (I thought the GT42 was big - it's got nothing on this giant hairdryer). I plan on finishing the exhaust downpipe, intake and alternator mounting for this weekend, I'll post pics then.

Still need valve covers, anybody have a set?

vanillagorilla

iTrader: (1)

I thought the VNT turbo's need some sort of electronic control system. Where did you get this turbo from, a diesel?

chuntington101

great project mate!!! need some new pics though!

also as vanilla said, how are you controling the VNT???

thanks Chris.

Jake@EPP

You may be able to control the VNT solenoid via megasqts IAC settings , depends if yours is boost operated or electronic.

bigturboz28

Everything is installed, and by everything I mean...

1) New Engine - 402 ls2 stroker with wiseco 8.8:1 pistons, hellfire rings, howard's billet steel rods, eagle crank, all arp studs and patriot stage 3 heads, 246/240-114 comp hr grind cam
2) New T56 tranny - Built by RPM transmissions
3) New Driveshaft - PST 3.5" Aluminum
4) New Exhaust Manifolds - Built a la Me (2" ID. 1/4 wall thickness)
5) New Downpipe - 5" into 3" for now (to join to magnaflow cat back)
6) New Injectors - 96lb low imp
7) New Sensors - TPS, IAT, CLT, CMP, etc...
Damn are you as excited as me yet....
8) New Intake Piping- Built a la Me (3" ID. ABS piping)
9) New LC-1 Wideband O2 - Innovation Motorsport
10) New Tires/Rims - 315's in back, 275's up front
11) New Fuel Injection Computer - Megasquirt I V3.0
12) New Turbo - GT45V (VNT turbo capable of 115lb/min max)
13) New turbo oil return - welded a bung on the pan.
14) New alternator bracket - Built a la Me (moves it up above passenger head)
15) Reused previous clutch - spec 3
16) Reused previous fuel pumps - 2X Walbro 255 hp in tank
17) Reused rear end - Moser 12 bolt 33 spline axles
18) Reused Meth Pump - Will be Megasquirt controlled now
19) Moved Rad 1" down and 5" forward
20) Reused Magnaflow cat back
21) Reused Intercooler - Precision Turbo Front Mount Air-Air
22) Reused Edelbrock Torque Arm, SFC, LCA's, PHR,
23) Reused Tial 50mm BOV


I will be starting the tuning this weekend, everything is already wired up and ready to go (I left the wires all over the place in the pics in case I need to go back and change something).

To answer the question...
I use a pneumatic controller for the vanes, basically I welded up a bracket the reversed the turbo vane movement from it's previous application (diesel). on a diesel it is setup so that the computer tells the turbo to make boost, I set it up so it is normally if the fast spool mode (A/R 0.42) and then as it builts to higher boost (currently set to 15psi) it gradually goes to the low restriction setting (A/R 1.72). As stated in a previous e-mail, this same turbo was used on a GN application and it made boost sitting in neutral with no engine load (other than the turbo).

chuntington101

amzing work big!

do you think this turbo could work on a rear mount??? just thinking about the VNT and the effect it would have.

really amazing build though. cant wait to see what its like when completed!

CHris.

THE_SUPRA

subscribing for info on the MS.

bigturboz28

Well I started to tune tonight, so far so good, I spent most of the time reading the Mega Manuals which are Mega Good Reading! Anyway I setup all me basic parameters and got it idling nice and smooth at ~850-900rpm. SO just in case someone tells you that 96lb injectors are to big and you won't get a good idle, tell them they are wrong because it has been done, BTW look at the cam specs it was done with...

Everything looks really good and stable, so far this MegaTune is a breeze to use! I will fill in the rest of the map this weekend, I will keep you posted.

Can the turbo work on a rear mount - sure, will it spool as fast a front mount - no, will it spool fast enough to blow the tires off at 60mph - probably. I will let you know when I can check the spool time this weekend.

BTW, at idle, this turbo spools like a ************ compared to the GT42, and you hear a obvious whine AT IDLE! i had a couple backfires (simulate 2 step) and the turbo just took off like a shot, I thought my car was going to take off, it was pretty exciting, can't wait for the weekend!

chuntington101

what rpm spool are you hoping to get bigturboz28??? what point did you hit full boost with the GT42?? do you think it will be the same??

have you ever seen proper anti-lag is use??? its insane!

thanks CHris.

PlatnumStatuz

iTrader: (6)

looking pretty sick

Phil99vette

iTrader: (11)

Damn! looks good and quick progress, why did you just use straight pipe vs mandrel bent u bends?

MOLESTER

iTrader: (3)

I noticed that too, those angles are gonna create some horrible flow and excess heat.

bigturboz28

The mandrel bend pipes never really occured to me, I didn't think I would lose that much with the straight sections. If it causes a problem that piece is only a couple hours to fab up anyway. My old setup spooled to 10psi by about 4500rpm if I remember correctly, since this is a 402 (346 on previous setup), that alone will help tons. I am hoping for 15# by 3000rpm, but we will see.

As far as anti-lag, MS has a module for that too! The VNT helps when actually on the street/track - you don't have to be perfect driver to keep the boost up - it should make the car more fun to drive. 2steps are reserved normally for launching hard anyway. Once I get all the fuel / spark maps straight, i will play with add on stuff, water injection (that can use a seperate fuel map if needed when activated), built in 2-step, ignition retard based on turbo rpm, etc...

So far I am really impressed with the MS, I will post any drawbacks / stumbling points as I go through the tuning so others do not get caught, but the Megamanual covers alot of the normal hickups, it is very well documented.

bigturboz28

Wanted to start tuning BUT my wideband isn't working, that was the bad news. I set the fuel map so it is kinda rich but will run, I based it off Parish8's map (thanks again Parish8!) to go get some gas. The good news it is I live on a hill, leaving my house going down the hill and coming home going up the hill, who cares right? well going up the hill at about 20% throttle on a rich mixture at 1600rpm it built 3psi (I obviously was not trying to build any boost, i just wanted to go and get gas and drive it for the first time). I can't wait to see what this thing will DO!!!

A first glance, judging by that little performance (the way it spooled), these turbos should be really good for properly set up rear mount, I will confirm and take videos/post datalogs of spool time once i get me wideband working.

sevanseriesta

iTrader: (34)

sick, insanely sick....