SurfnSun

Are you going to start selling this as a kit?

lcvette

Good to see some old names coming out of the woodwork! as far as blowbye, nothing unexpected from a setup such as this. my very basic very simple catch can and vent system is working very well. I get about 1/4 cup of oil in the catch can about every 2 weeks or so of hard tuning and driving, and when I say hard I mean it sees max power through the gear frequently on tuning runs.


SurfnSun,

Yes, Please PM me for details, I spoke with troy about becoming a supporting tuner, but am waiting to have my website fired up as he and I agreed it would make better sense so until then I cannot discuss it much further on the public forum.

Chris

mseven

very nice build and great numbers
as to "sucking hind tit" a couple lsx twin tubo'd guys around here have seen around 960 at the tire. IMO your package is right in there, and I am sure you spent quite a bit of thought and time on this build. congrats

lcvette

Mseven, thanks for the kind words! and yes a very good bit of time and alot of it frustrating but worth it. I plan on pushing the new setup well beyond the 960 mark.. the goal is to hit the 1000rwhp mark as it seems like a nice round even number and the extra digit seems to add some wow factor. obviously even this much powr as the kit is making is difficult to control on the street on drag radials but I feel the guys who have dedicated drag suspension /solid axles/ automatic built tranny's will be interested and benefit from the power. I would like to see C4's running around more on the internet track videos floating around.. if you guys are like me its exciting to see one of our cars on streetfire or youtube turning in 7 or 8 second timeslips.. most impressive! I want to offer some umph to help get more of these cars there!!

Chris

lcvette

Added some pictures to the thread in the first post!

Chris

Sunyi

Hi guys, sorry for borrowing the thread but I really would like an opinion on my cam setup. I´m having the guys at www.cnc-motorsports.com to build a strong 421 bottom end for me. The haven´t started on the build yet and I can still change my mind about the cam and all the other parts for that matter.

I´m concerned about the asymmetrical duration and the LSA.
What do you think?

I want the engine to run just as steerable as Lcvette´s and still kick just as much ***.

1987 C4, ZF-6 black, McCleod TD clutch, Steel FW, Dana 44 3,58, Z51, 13" rotors, 421 Dart Sportsman Little M 1pc seal, 3.875" Crank, 6.0 H Beam custom JE forged pistons 8,5.1cr, HSR, 58mm TB, 80lbs injectors, Megasquirt, WB lambda, AFR eliminator 75cc/210cc, 1.5 roller rockers, Comp Cams Hydroll NX276HR 224in/236ex .502/.520 113LSA, Kevko 8q pan, HV oilpump, Hitachi ministarter, Twin T3/T4 hybrid .50 A/R compressor housing .63 A/R turbine housing, SS manifolds, 2 x 35mm WG, FM Alu IC

lcvette

I see several things wrong in your combination, there is a large mismatch of components for you to reap the rewards of full potential in your combination.

first things first.. your tubrocharger choice is WAY TOO SMALL! a 421ci motor on T3/T4's especially with those tiny exhaust housings will choke your engine.. a 421 would want a minimum of T4 based 63's but I would look at 66-67mm units and good flowing manifolds. the cam is fine, I use head flow data to determine if a single pattern or split pattern camshaft is desired. generally with high flowing well ported exhaust ports a symetrical exhaust lobe can be used, when you have poorer flowing exhaust ports a split pattern camshaft is more desired to offset the flow restriction of the port.

in a turbocharged application there is a little bit of voodo involved because you will always have excessive backpressure so too much exhaust duration and overlap creates reversion in the chamber and you will lose efficiency of the air pumping system the engine is.

cam would not be my main concern as much as the turbochargers. on a side note a 421ci motor is not needed to make big numbers and while it will do so on less boost, you will run out of components in the motor to make up the difference in power long before it becomes a valid issue in my opinion.

meaning, smaller cubes and stronger parts because of it will yield a safer more boost friendly motor that will still make more power then you will be able to plant to the street. the other benefit is a higher revving motor with a longer power curve will be a faster car overall.. more raised area under the power curve and more ability for the gnine to continuously be accelerating with power increase.

This is the main reason the Toyatoa supra with its broad RPM range and high boost settings accelerate so ridiculously fast.. they continue to make increasing power to redline which is MUCH further then most conventional V8's will spin.

Chris

Chris

Sunyi

Ok, thanks for the input. Looks like I will have to go and get a couple of T4´s and reweld the manifold flanges... By the way, my primary pipes are 1 5/8".

The T3/T4 hybrids were included in a kit I picked up on ebay.
Thought they would make a good starting point and go from there.

My thoughts when I selected the 421 were that I did´nt have to crank up the boost that mutch too meet my 600rwhp goal and have a strong and driveble motor with lots of botton end torque. The other reason, I know its silly, the show-off factor

Good thing that at least my cam is ok though.

Although I am still a bit concerned about the 113 LSA. What is your oppinion on how they match the (stock) 210cc AFR eliminators (exhaust port flow wise)?

What other cam choices are there out there that would be more suited for a turbocharged engine. (more LSA).

By the way all the bottom end components will be forged pieces. I´m not planing to spin the engine above 6500rpm.

lcvette

I run a 115lsa becvause I wanted this car to be the apitome of performance and comfort and driveability. I also chose a rather small camshaft duration to maintain idle quality and part throttle cruising smoothness, no cam surging at low RPM!

Your primary tubes are too small for you combination as well, I would do 1.75" minimum and prefer 1 7/8" for better flow..

your car will make a ridiculous amount of low end torque with small turbos but be no fun to drive as you won't be able to connect the power to the ground.. that much torque at low rpm with that many cubes results in alot of fuss down low and nothing impressive after torque peak.. it will be like a L98 Tuned port car, all throttle hit and no power up top.

you will find you will risk more damage to the engine by using such small turbos and primary tubes by creating exccively high turbine inlet pressures. this leads to blown head gaskets, detonation, lifting the heads and pushing coolant and extreme engine temps and heat cycles to the turbo and manifolds. this is the glowing red and transparent effect of too much heat and to low of an efficiency on turbo sizing.

Chris

bill mcdonald

what kit did you purchase on ebay?
I only mention it because I have a few turbo parts from things that dont fit in the vette. and if you purchased what I think you did, I asume you are welding and fabbing on it?

bill mcdonald

How do you think a 400 or 406 (large bore) will do with a large single?
I figured this might be a cross section for strong parts and stroking it out?

Other wise, maybe I could just focus on a 383 and be done since my 355 needs new stuff anyhow?

Sunyi

Bought it here:
http://stores.ebay.com/E-Sales-Race-Distribution

I haven´t recieved the shipment yet, but I am certain that it needs extensive rework to fit.

The other parts listed are not yet ordered. Still negotiating with cnc-motorsports. It is hard for them to fit all parts and labor within my 11000$ budget.

The last news from them were that they wanted to swap my AFR´s to a set of RHS aluminum cylinder heads

Lcvette made me reconsider about the 421 block. The last thing I want to do is build a pig that can blow up.

95wht6spd

"smaller cubes and stronger parts because of it will yield a safer more boost friendly motor that will still make more power then you will be able to plant to the street. the other benefit is a higher revving motor with a longer power curve will be a faster car overall.. more raised area under the power curve and more ability for the gnine to continuously be accelerating with power increase."

Are you basically saying the weight of the bigger engines rotating mass will shorten the life? Is this why you did a 355 VS 383 etc.?
So what is the ideal CI for a V8 turbo in your opinion? I would think a 383 would be better if both used the same quality parts, everything set up properly, and making the same power because you could use lower boost, which I thought would make the engine live longer?

bill mcdonald

That link shows a list of parts for sale. I asume you picked up the camaro TT package.


I have these headers, just a heads up, the turbo flanges will hit the a arms on the C4. you will need to figure out how to deal with this. I was thinking maybe you could raise them to go over the a arms. I just put them back in the box. Maybe one day someone will give me a camaro.

Iroc57

Very impressive but I too would like to know how much $$$ something like this will cost

lcvette

95wht6spd,

in a stock deck height motor, by adding .27" stroke with a crank shaft, you generally will open up a few other variables, nominal is a 6" rod to maintain a optimal rod length to stroke ratio, this will maintain a better thrust angle in the engine, a 5.7" rod on a 3.75" crank is doable but it will increase the side loading of the piston in the bore.

how this effects a boost motor is as follows. by using a longer stroke and longer rod, but maintaining the factory deck height or in most cases cutting the decks even if to true them, you push the piston pin hole further towards the top of the piston. this compresses the ring pack closer to the top of the piston. this weakens the most vulnerable portion of the piston and generally speaking the failure point of an FI motor, the top ring lands.

If you do the math on what 28 cubic inches will gain you in the long run on a boosted motor, it is absolutely useless, you can gain more horsepower and torque from adding (1) psi of boost to a 355.

I built a 355 because I understood this scenario and knew that I would be pushing this motor as far as it would go. the elevated cylinder pressures in a high boost application will take their toll on a piston with a weak ring land, if you ever get a brief spot of detonation the pistons will fail at this point.

If you desire more power at lower boost levels, then add cubic inches in large scale but do it so that the motor can be built to handle it. this will mean using a tall deck dart block so that piston design strength can be maintained as well as a significant addition of engine volume. a 383 is near pointless. when 1 pound of boost will net the same output.

if 16psi on a low compression motor and 93 octane isn't acceptable to you and making ~700rwhp on a 355 then you are well beyond what pump gas and a 383 will make you happy with as well, and you will be switching to E85, or race fuel. at this point its your best bet to have the strongest engine to handle you goals and the stock blocked 383 isn't it.

I only offer my recommendations based on math, if you WANT a 383 by all means take this route, some may just want to run 5 pounds of boost and be able to state they have a turbocharged 383.. which sounds great but..... I would rather have a safer option and be able to push the package further with smaller cubic inches and more RPM potential.

regarding RPM potential, whether forced induction or naturally aspirated, the factual basis that reduced rotating mass will always make for a more reliable high revving setup. the added weight of the extra stroke crank and longer rod will increase your inertial load a good bit. once you get in the higher rpms this becomes exponetially more significant.

again I just offer my opinion. I am the guy doing it not speculating about it. I know what I wanted to handle my goals and it is doing so. I guess you could say this is a PROVEN method..lol

Chris

lcvette

Iroc57,

I am not a supporting tuner for the corvetteforum.com just yet so I cannot post prices in here and do not want to take away from any other tuner/vendors that are currently paying the fees.

I will be a supporting tuner in the not far off future and this will change, until then if you have questions about anything you can email me or PM me and I would be happy to answer any questions you may have.

Thanks!

Chris
Lcvette1@aol.com

ol school

Holly S---T ,
a thrill just watching the video !!! truly insane...

95wht6spd

OK thanks for explaining the details. I didn't realize 1 PSI would equal the extra cubes, thought it would be more like 5-6. I am not up on the details of FI, just basics.
What about a de-stroked 377, or is a 355 the best we can do since we have to use a GM LTx block?

Iroc57

Thanks but it was more of a ballpark that I was looking for out of curiosity. It wouldn't be worth taking up your time for a quote.