99zvert

alright first i'll get my intro out of the way. my name is mike i've had my 99z28 since it was new and paid it off just recently, i bought a daily driver so now the z is in the garage indefinitly until all plans for it materialize. i have been reading this forum for about a year and never voiced my questions, just merely took the advice others were given. i read some books about f.i. and feel i've got a ton of info in my brain but i need some help in applying it to my car. so here it is.

i'd like to use my stock block if at all possible since my 'vert is already heavy enough. i want more cubes before more boost so if i did a 382 stroker with some 6.0L LQ9 heads, maybe the aluminum LQ4heads since the cr is lower, and i want to go twin turbo since i'm not looking for a max effort race car, just a sick ground pounding street car. i want to know if anyone has done exactly what i'm talking about, i know there are a few. and i know there is the CAS kit out there right now but i'm having trouble finding any other companies with kits already packaged for the f-body so maybe you guys know of some others. this will be my 1st ever engine build up so any advice on the walls i'm gonna run into will be lots of help. this project will probably take all year but i'm okay with that i just want to get all the right components set in place that will work together instead of slapping together a prefab motor package someone else has put together. i need suggestions on the motor build for parts from the crank to the heads. money is a bit of an object but for people like me it always is that's why i'm not rushing so any help and guidance is appreciated and thanks again for reading all of this.

mike

99zvert

geez don't everyone jump on this at once. i know for a fact that this forum is full of very smart individuals willing to help, but somehow i'm not offered any. is everyone too busy or what? just wanted some feedback. maybe i'll go to the "other" ls1 site.

mike

Pro Stock John

iTrader: (34)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 99zvert:
<strong>maybe i'll go to the "other" ls1 site.

mike </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Dang. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

You can stroke your stock motor with a Lunati setup or even with a crank from a different provider like Scat.

Since twin turbos have excellent mid throttle response you might find that doing a 382ci is not needed. I think you can do a .005 over stock block with 6.125 rods and 9:1 pistons and 6.0 heads. That's what I am doing now but I am doing a Vortech YS supercharger.

www.chargedair.com has a twin kit that they sell exclusively through www.ls1speed.com.

CHRISPY

Keep your stock crank.
Get forged 9:1 3.905 pistons like PSJ said. Throw in good rods and rodbolts and have fun. As for the heads go for something that flows in the 300cfm range @.600 lift and a decent turbo cam.

Good luck,
Chris

99zvert

thanks guys, so i could basically stay with my stock block and upgrade internals? i just thought the stroker kit would give it that much more you know, maybe i'll rethink this one.

mike

Malicious

iTrader: (1)

Harlan's twin turbo car is what, 348 cubes? Jus a lil over stock and made 700 to the wheels on a mustang dyno and has gone 10.0's with enough MPH for 9's? Big cubes are nice but the power is there for "stock" cubes <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

KHShapiro

iTrader: (10)

as far as a kit why not look into LS1Motorsports kit? www.ls1motorsports.com and they have specs on there motors

<small>[ March 06, 2003, 08:16 PM: Message edited by: KHShapiro ]</small>

99zvert

well i did look at ls1motorsports kit, but from what i have read about single turbos it doesn't seem like the path i want to go. this car is going to be a street car only so the quicker spool is what i'm looking for instead of monster boost. plus as i stated earlier i don't need a full out race car and ls1motorsports' car is. no disrespect to the single turbo guys but i think twins are a better option for me personally.

mike

Speed

iTrader: (33)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 99zvert:
<strong> well i did look at ls1motorsports kit, but from what i have read about single turbos it doesn't seem like the path i want to go. this car is going to be a street car only so the quicker spool is what i'm looking for instead of monster boost. plus as i stated earlier i don't need a full out race car and ls1motorsports' car is. no disrespect to the single turbo guys but i think twins are a better option for me personally.

mike </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No disrespect taken but the idea that a larger single spools slower than two twins is foolish. The thing everyone seems to forget is while you have a smaller turbo to spool, you have exactly 1/2 the exhaust energy to spool it. I can build you a single turbocharger that has less total turbine housing area resulting in faster spool than two twins. I can also match the compressor wheel and housing to give you faster boost response as well. You have a great deal more to work with when you are dealing will all the exhaust energy and a single turbo configuration.

My single gets positive manifold pressure at 2k and comes under full boost (11-12lbs) at around 2800-3k. I also have a great deal of room for improvement in my induction and exhaust system tracks. I also loose less than 10% of my manifold induction system pressure between shifts. What pressure is lost comes back nearly much faster than it might with a supercharger. This is because the turbocharger is still spinning at nearly full speed when the throttle is reopened. The drag in the amount of time between the throttle opening and the pressure wave hitting the turbine is almost null.

Don't get me wrong, my current buildup will have twins. Twin T72s. I've designed twin systems and they work fine. But it's just seems to be a common misconception that twins spool faster.

99zvert

so speed you have built turbo systems before? if you wouldn't mind i'd like to pick your brain on the subject sometime. i like the kits out there but i also know that all turbos have to be matched to an engine package to be effective, the engine package i'm looking at right now i haven't seen tried yet so i want to see what you think. send me an im or just reply here.

mike

Speed

iTrader: (33)

Not a problem, Just email me at bryan_es@yahoo.com with any questions you have and I'll try to answer them.

smokinHawk

iTrader: (48)

I get 0psi (no vacuum) any time i step on the throttle (like 1700 rpm) and full boost 10psi at 3k rpm with my T-76 single.
Spool is not an issue with a 348 V-8. Even with out boost the engine still has power NA.