Guys, I need some honest advice on my project

bhays

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Indiana, USA
I have really grown to trust this forum and several of the guys here for advice as opposed to some of the others where there seems to be a lot of pretty questionable advice being tossed around. I was hoping someone could give me a little advice on what to do here. I have a dilemna on the direction to go with my forced induction plans.

About a month ago, I bought a Vortech V2 S-Trim head unit. It is freshly rebuilt, polished.. gave $1000 for it on eBay. I sent it off to Street & Performance since I have their serpentine and TPI setup on the car to determine the best way to mount it and the brackets, etc. I would need. I think it will probably fit and I am guessing that other than an injector upgrade and a bypass/blow off valve, I won't need a whole lot more to get it going. I assumed it would end up being about a $2000 total deal to get it going.

I have a chance now to buy a rear mount twin turbo setup brand new that was designed for a C5. It's not an STS, but similar, the turbos are jdm gt28 with internal wastegates, the oil scavenger pump, lines, etc. complete kit. The seller wants $1700. The kit came from this seller, but is the upgraded turbos and complete kit.
http://www.ebay.com/itm/221136301026?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

I am all about doing something unusual with this car as it's a very long term project that I have been wanting to finish for a lot of years. The body is just about to come off and I will have plenty of access to route the cold air back, etc. In looking under the car, it seems fitting it all shouldn't be a problem.

This car is just going to be a fun car for street use, I just want it to have a lot of punch, but I am dead set on the idea of having forced induction. I will attach the info on the engine I have to the post.

Should I buy the twin turbo kit and sell the vortech, or go forward with the vortech?

attachment.php
 

Bullshark

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Just my 2 cents here, but I am not a fan of that C5 turbo setup. I can't think of a worst place to locate turbo's than at the end of the tail pipe as far away from the engine as possible. Trying to regulate the intake manifold pressure is hard enough without introducing the additional turbo lag due to the time it takes the exhaust to react with those remote turbos. If your only concerned with WOT and not dynamic throttle response, than I guess they will provide some benefit. Keep the Vortech V2's if this is your only choice.
 

Twin_Turbo

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The vortech bracketry, pulley setups and tensioner are way better than the junk procharger sells for the sbc. They also have good spare/replacement parts support. Procharger will just want you to send in your stuff to send a nice fat bill. Their customer service sucks.
 

rtj

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If want a cost effective motor for boost, guys with stock iron block ls engines seem to get away with a lot of abuse.
 

SuperBuickGuy

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My issue is with using Chinese turbos in comparison to the Vortech. The Vortech will last you a bunch longer then ebay-sourced chinese turbos.

I run chinese turbos because they're cheap on cheap motors - so when they go boom, I might have 1-2k into the entire motor/turbo set up. So far 3 failures, all of them were because impellers failed and threw crap into the motor.

my 2cents - stick with the belt driven blower; for a DD/fun car, a blower is awesome; turbos have their place (and I'll probably never do another blower), but from what your choice is (the one you laid out).... stick with the Vortec.
 

Twin_Turbo

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Will be fine as long as you use conservative timing, premium fuel and have enough enrichment. Detonation and it will be over quickly :D
 

bhays

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When I decided to go this route, I knew I would need to become educated on tuning. I have been following this guy on Youtube and learning a lot. He was running a stock camaro iroc motor with boost which held up fine, now he's running a zz3 which lists its pistons as cast hypereutectic aluminum. He's running a single large turbo, otherwise it's TPI real similar setup to mine... going to get him to help me with a base tune for megasquirt.

http://www.youtube.com/user/zz3astro/videos

This video on how to add a turbo to a TPI motor was the most informative thing I found when I started researching all of this:

http://youtu.be/W7wqetv1UQw
 

SuperBuickGuy

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Forgive me for restating this, but is this accurate?

1) you've never owned a boosted motor prior to this one
2) you've never tuned a EFI prior to this
3) your information is coming from some bloke on the internet

I've grave concerns - Never use hypereutetic pistons in a boosted application as TT said, if you detonate, it'll be over quickly. Then you said "oh, and we need to tune the megasquirt".... I promise, you'll detonate while doing that... and you don't have a knock sensor to aid you in detecting knock. My bet is the motor never sees the street because you'll blow a hole in a piston...

But that brings up even a bigger question - you internet expert claims to be using those, and that brings up a huge question in my mind about whether or not he's an expert.

Forged pistons are a couple hundred dollars, getting them balanced and pressed onto the rods really isn't that expensive

... and stop listening to this "expert"... please

if you need a picture of what knock will do to forged pistons - I'll work on finding one that happened to me (leaking intake gasket where the knock wasn't very apparent)
 
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bhays

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I am here to learn and not trying to imply that I have any knowledge whatsoever. On the forums it seems I see hundreds of people with stock LS engines running all kinds of boost.

That said, I am pulling the engine to repaint the block anyway and I want to do this right within a budget. Given the engine specs I posted, what changes would you recommend to the engine without going overboard? Do you think my rods will be ok with new forged pistons or should I replace those as well?

I apologize if I came off as talking out of my ass. I don't know anything about this stuff and will be the first to admit it. I'm just trying to learn.
 

Twin_Turbo

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I would stick with a stock ECU, for drivability it is very hard to beat. You can run code 59 on a SD F boy or vette ECU and use a 3 bar map.

If you are pulling iat apart, get the best stuff you can afford and set the top ring gap a little wider, especially with hypers.

I would run it as is. That ZZ4 engine has a lot of CR, small 58cc heads (vette L98 D port heads)
 

bhays

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I would stick with a stock ECU, for drivability it is very hard to beat. You can run code 59 on a SD F boy or vette ECU and use a 3 bar map.

What would you do for ignition under boost? MSD 6AL or just let it go with the stock stuff?
 

Twin_Turbo

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I use a crane hi 6 w/ dial in retard per psi (TRC-2) but I have it set to 0 on both cars running it. I did all the timing with tuning (and both are not running code 59, one is running an extended range maf code the other is running a 6E SD code that I modified)

I woul certainly go with some kind of dial/switchable retard in case you get some crappy gas or whatever.
 
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