compound boost?

[Alex77carr]

Hi guys. my name is alex, haven’t been on the forum in awhile because my project has gotten parked under a tree for the past year. but I am damn determined to finish my frame off restoration and build a prow touring 77 nova or die trying.
i know im young, but i have thoroughly convinced myself that compound boost is the way i want to go, and maybe a shot of nitrous just for good measure.
i have done a little research on the subject, nothing extensive, but what i think i know is this...
a supercharger is great for torque, instant boost right off the line. but on the flipside a supercharger starts getting inefficient at high rpm's. The ratio at which the drag on the motor, and heat generated to the ratio of power produced starts to change the faster the screws spin.
A turbocharger has great efficiency, great for high rpm power. but as we all know you must sit and wait for them to spool up, or have a trans break.
So here is what im thinking...
take my L67 and add big twin turbos. put something like an A/C clutch on the front of the supercharger, so that right before it starts to get at inefficient rpms the clutch will disengage, and by that time the turbos will be spun up, and the little red nova will take off into the sunset, and out run reality its self.
i picture the turbos bypassing the supercharger all together. i notice on my L67 that there is a plate that covers an oblong hole in the back of my intake, maybe i could port that out and just plug my turbos in there? idk what the intercooler set up looks like, but maybe the turbo boost could still go though the intercooler that way? IDK!! one thing im having trouble picturing is deceleration; lets say your supercharger kicks off at 4000 rpms. what happens when you decelerate? Dose the SC kick back in at 3999 and then just bypass it? all i know is that if i let off the throttle at 10,000 and the motor winds down to 3000 and all of a sudden i go wide open throttle again the supercharger needs to kick back in. Im also not positive on how to run the air intake piping? i know all air must be metered though the maf sensor, but if the SC is producing more of a vacuum through the throttle body than the turbos, will that cause some kind of turbulence or rob air from the turbos?
I know the motor must be built well if i hope to reach 45 psi of boost at 10,000 rpms and have the motor stay together for more than 2 seconds.
im thinking of doing ARP everything, smaller SC pulley, find some decent priced forged pistons and rods, blue print and balance everything, port the heads, big valves, stiff springs, intercooler. big injectors, 1.8 rockers, oil cooler, NOS, insane pcm tune,..
i wonder if you could program a sport mode and a economy mode???
the goal is 30mpg on the high way.
Realistically this project will not start for another year or maybe 2, but i find myself daydreaming about this set up at least once a day. dosent matter if im at work or boinking my girlfriend, this idea demands my attention.
So if anyone out there has any ideas or has anything to add or subtract, im all ears..
PS i dont want to spend a dime more than $7000 on the motor. anything over that i might as well build an LS7.
Thanks,
Alex Carr

 

[bison]

With the turbo and converter tech these days there is minimal response time and trying to compound boost a small engine like this is a waste of time and expensive. If everything is working the way it should then you should be able to make 700-800hp and have very good response time with just a single turbo. If you dont want to spend over $7000 then you better just buy a stock LC2 and do a bunch of bolt ons. $7000 wont get you too far. Its a lot cheaper to keep boinking your gf and daydreaming about it. Just make sure you use condoms every time!

 

[rmar]

$7000 wont get you too far. Its a lot cheaper to keep boinking your gf and daydreaming about it. Just make sure you use condoms every time!

That's deep.
Words to live by..........




.

 

[Spooln1]

Compound boost, twins turbos and a SC, built to handle 45 psi, spins to 10k, gets 30mpg and "if it could be done" all for 7k..... keep us updated on the progress.....

Tried educating myself a little on the subject of compound boost. Looks like Hellion is making kits for mustangs. Would be well over the 7k price tag for the turbos and sc kit itself.

http://www.hellionpowersystems.com/index.php/compound-boost-resource

 

[Alex77carr]

birthcontol trumps condoms.
i really think it can be done under 8g's.
all im doing is taking a heavly moded suppercharged motor and adding turbos. so you spend $5500 on a bad ass suppercharged motor then spend another $2000 on turbos.
under $8000 right???
idk, at some point ill sit down and do the reshearch and find out the going rates on parts, machine shop prices, ect...
but im more worried about the theroy of this subject. tuning, how to run the pipping, air flow charts and stuff like that. iv never taken physics and know little to nothing about tuning.
but im damn determind to learn.

 

[JT'sV6]

You ever rode in a 650+rwhp single turbo car that hits 25 pounds of boost in under a second? If your ever in swva look me up and I'll give you a spin

 

[bison]

birthcontol trumps condoms.
i really think it can be done under 8g's.
all im doing is taking a heavly moded suppercharged motor and adding turbos. so you spend $5500 on a bad ass suppercharged motor then spend another $2000 on turbos.
under $8000 right???

nope

 

[ronbros999]

Nope, an L67 aint gonna handle 45 psig inlet manifold pressure, no matter how you build it!

 

[Quik Six]

With the turbo and converter tech these days there is minimal response time and trying to compound boost a small engine like this is a waste of time and expensive. If everything is working the way it should then you should be able to make 700-800hp and have very good response time with just a single turbo. If you dont want to spend over $7000 then you better just buy a stock LC2 and do a bunch of bolt ons. $7000 wont get you too far. Its a lot cheaper to keep boinking your gf and daydreaming about it. Just make sure you use condoms every time!

Brian: Don't you know condoms don't guarantee safe sex anymore? A friend of mine
was wearing one when he was shot by the woman's husband.

Phil Engle

 

[bison]

Nope, an L67 aint gonna handle 45 psig inlet manifold pressure, no matter how you build it!

Not going to handle 45psia too easy either

 

[Alex77carr]

well there is only one way to find out.
when i save up the money to get this project off the ground. ill post pictures and video of the tack at 10,000 rpms and the boost gauge at 45psi, or of a catasrophic fail as the heads blow off and the rods shoot through the pan, and my car burns to the ground.

 

[chopped39]

45psi and 10,000 rpms do not belong in the same sentence unless your building an Indy car . Toss the charger and run a single turbo.
Listen to Bison he will save you a bunch of money and a ton of time.He knows his sh!t.

 

[Alex77carr]

You peoples do you know that im 20 years old and if you tell me i can’t do something it makes me want to do it just that much more right?
But I do except the fact that there are probably a lot of people on here that have alot more knowledge, and experience than me. With that being said, all i have at the moment is alot questions. And if you were to tell me to shut up and go do the research myself and read a book or ten i would understand...

So you guys really don’t think the gm 3800 can handle that kind of punishment? Even with forged and balanced internals?
do you think the iron block, heads, and crank are not strong enough?
I know gaskets would be an issue, but i think one could get around that with copper or aluminum gaskets? and studs help as well i think.

What factors limit the rpms in an internal combustion engine?
CFM, fuel volume/pressure, injector size, valve spring tension, rockers, bearings/friction, compression, weight and strength of internals, air flow characteristics, cam duration/overlap, valve height/travel, ignition timing/advance??? or just overall efficiency of the motor?

What dose it take to build a bullet proof motor? besides money that is.
What is the biggest badest 3.8L know today?
I wonder what an indy motor cost ?
What are cylinder head options?

It has also come to my attention that i may be limited by the quality of today’s fuel, i know that there is a lot of determing factors besides the compression ratio that limit your options on fuel, even though i dont quit fully understand it all yet. but i cant afford to run race fuel in a daily driver.
What are the best quality turbos offered for this motor?
can i use different turbos and expect them to just bolt up to the headers? or will it take extensive fabrication to slap 2 monster turbos on?
What kind of boost can i expect to get out of certain size turbos? or is there other factors that determine boost besides size?
How dose nitrous + boost work? do you have to drill holes in the intake under the supercharger?

If i did go through with the compound boost would i have to put a cut off valve on the SC inlet so when the turbos kick in they dont try and pull a vacuum through the supercharger?
If you did run the motor without the Supercharger spinning would that be a vacuum leak?
Where is a good place to start when trying to learn how to "tune" and dial in a motor?
how good and how expensive is it to have a engine dynode out of the car? would they be able program the pcm for compound boost, or just heavy mods?
why is the knock sensor such a big deal when dialing up the boost? and would it be a bad idea to deleat it if kr became to much of a problem?
If im pushing 4 times the power out of this motor than it was originally designed for, Am i going to run into a problem with the parameters in the sensors? If so, can some of them be reprogrammed? If not how do i get better sensors?
When dose the OEM pcm have to be upgraded?
Is the fuel regualtor going to be a problem?

pretty sure the l32 pistons will fit in the l67 if you swap the rods as well, but Is it possible to use different pistons? Like could i have the 3800 bored out and use honda, or sbc pistons, or something close? because if it could be done than all of sudden forged parts just got alot cheaper and there is possibly alot more options on price and quality of the parts up for grab for this motor.

How hard is it to bolt up a tremic T56 6speed trans?
if im getting more than 550hp out ot the motor what are my options for a street able clutch?
what problems am i going to run into with a rwd swap?
what kind of options are there when considering oil pan and oil pick up?
has anyone ever hooked up a dry sump system to this motor?
Is there such a thing as performance bearings for this motor?
Is it possible to build a 3800 with big hp numbers and still have it reliable? if not abused get 150,000 miles +

any knowlege would be kool.
Thanks.

 

[JT'sV6]

When you speak of a 10,000rpm capable 6 cylinder motor, the ford 4.5l svo comes to mind. It was used in the nascar busch series and was built to sustain those rpms for for a long duration of time. Every now and again one will pop up for sale over on racingjunk.com.

 

[ronbros999]

if you are going to build this project,you should KNOW ALL the answers to the questions that you just asked already!

because if you dont ,then have someone else build it, in other words ,etheir you know how to OR you dont!

and by reading your posts,, you are very young and no experiance in actual hands on projects.

of course do continue with your DREAMS!!!!

 

[aminga]

You peoples do you know that im 20 years old and if you tell me i can’t do something it makes me want to do it just that much more right?
.

Then you can't run 25 lbs of boost on 87 Octane.

 

[ronbros999]

not without AUXILIARY INJECTION of some type.

course you could ,but i dont think you would like the results. puff the magic DRAGON.

 

[Dusty Bradford]

A 10,000 rpm motor requires over $4,000 in valvetrain alone. Jesel lifters, rockers. Ti intake valves, custom pushrods, good springs, billet crank, light weight rods and pistons.....etc.

No need for that kind of rpm. The mod motor Cobra's have a compound system that works very well. They use twin 57mm's blowing into the factory blower. Over 1000hp at 7500 rpm if they push it. 700-800 is very common for the average car.

Like has been said already. You need to know the answers to all the questions you have asked, then you will know why it can't be done with that motor on that budget.

 

[Alex77carr]

Thank you for your input guys
i do have a little experience, iv built 3 cars and owned about 5. finshed a 2 year degree in auto tech. worked in the industry for a year. nothing to brag about, But i have little to no experience with these motors or anything to do with high performance, so thats why i ask questions. But thats okay i do NOT plan on building this project tomorrow, i plan on knowing all of those questions and much more before i actually start buying parts, iv got plenty of time to save my money and do reshearch,most of the knowlage is out there i just have to hunt it down, and i plan on it just as soon as time and budgit alow. I may blow up a few motors and transmissions learning how to build the meanest V6 on the road, but its only money the rest is just an excuse to get my hands dirty, perfect a skill ,and learn from my mistakes.
Thanks again guys,
ill come back after iv done more research and im much closer to the build.
or we will all die in 2012 and nothing i said matters.

 

[ronbros999]

after the nuclear holocaust, the only thing still running will be a DIESEL!!!!