Thinking About A 408 Stroker 8:5:1CR Ideas?

[NeeD4SpeeD]

How many PSI is irrelevant; it's just a measure of restriction to the air, CFM matters. 14-16 range will be getting close to max speed to spin the blower to on an engine that size. That's why I said if you want more later, go F1 in the beginning when it's affordable.

Well did you hear what that fukin F1 sounds like!! lol Zboner posted a clip on how it sounds and it sounds awesome but for cruises and around the streets i think it might be alil too loud.... anyway to hush it abit?? lol And with the 408 i am looking for 9.5:1CR so i was thinking -28cc dish pistons with the afr 225 66cc heads to bump the compression up am i headed in the right direction??

[Olde Skoole]

the whole purpose of building a supercharged motor is to force pressurized air into the combustion chamber......the lower the static compression ratio the more boost you can dial in.
The more boost pressure you have the more power the engine is going to make, Centrifugal blowers are of the positive displacement i believe and make power just above idle...therefore a moderate static CR is not recommended unless the engine is turbocharged as it takes a moment or 2 or 3 for the turbo to spool up and make boost....
7.5 or 8:1 is a reasonable static CR for a supercharged engine and will allow the end-user to use moderate to high boost pressures (10psi+) and achieve big power gains..
just my $.02

[Olde Skoole]

Zboner posted a clip on how it sounds and it sounds awesome

damn skippy....sounds real good!!!!

but for cruises and around the streets i think it might be alil too loud....

Nonsense, if it's too loud your too old

anyway to hush it abit?? lol

Sure, just remove the drive belt...lol

And with the 408 i am looking for 9.5:1CR so i was thinking -28cc dish pistons with the afr 225 66cc heads to bump the compression up am i headed in the right direction??

Yes, if your not planning on supercharging, flat-top pistons with big-chamber heads would be a better choice

[Olde Skoole]

As a added note, i believe a slightly dished piston (if the dish is centrally located helps to centralize the combustion pressure on the rod which decreases side-loading on the piston contributing to decreased cylinder wear..
I would recommend using the largest combustion possible and then determining how much dish is required to achieve the desired CR...
I also believe that that if ask 10 different people how to build a engine for a specific application you will get 10 different answers...
We all have our own philosophies and beliefs, this is why we have forums to discuss these variances and share them with each other....good luck with your build.
BTW, i would strongly recommend reading some tech articles on supercharging in the meantime.

[NeeD4SpeeD]

damn skippy....sounds real good!!!!
Nonsense, if it's too loud your too old
Sure, just remove the drive belt...lol
Yes, if your not planning on supercharging, flat-top pistons with big-chamber heads would be a better choice

LOL... Im def not too old what was i thinking...

Well the 225 afr are big chambered heads and your right the flat tops are better i dont care about the short term hp i gotta think about what my goal is which is the supercharger...

[NeeD4SpeeD]

the whole purpose of building a supercharged motor is to force pressurized air into the combustion chamber......the lower the static compression ratio the more boost you can dial in.
The more boost pressure you have the more power the engine is going to make, Centrifugal blowers are of the positive displacement i believe and make power just above idle...therefore a moderate static CR is not recommended unless the engine is turbocharged as it takes a moment or 2 or 3 for the turbo to spool up and make boost....
7.5 or 8:1 is a reasonable static CR for a supercharged engine and will allow the end-user to use moderate to high boost pressures (10psi+) and achieve big power gains..
just my $.02

Well said... I totally understand.. I was thinking of the short term power ya know like after i get everything installed short term and i wasnt thinking about the big picture and my overall goal which was bad on my part... But very well said man!

[NeeD4SpeeD]

As a added note, i believe a slightly dished piston (if the dish is centrally located helps to centralize the combustion pressure on the rod which decreases side-loading on the piston contributing to decreased cylinder wear..
I would recommend using the largest combustion possible and then determining how much dish is required to achieve the desired CR...
I also believe that that if ask 10 different people how to build a engine for a specific application you will get 10 different answers...
We all have our own philosophies and beliefs, this is why we have forums to discuss these variances and share them with each other....good luck with your build.
BTW, i would strongly recommend reading some tech articles on supercharging in the meantime.

Your right it's everyones personal opinion to how good or bad something is or how much of something to do or not do... But i'll take it all into consideration and i have been reading a bunch of tech articles on supercharging in my spare time which isnt much lol but im doing what i can... You advise defiantly helps so thank you... Always good to hear honest un biased opinions!

[Frost]

the whole purpose of building a supercharged motor is to force pressurized air into the combustion chamber......the lower the static compression ratio the more boost you can dial in.
The more boost pressure you have the more power the engine is going to make, Centrifugal blowers are of the positive displacement i believe and make power just above idle...therefore a moderate static CR is not recommended unless the engine is turbocharged as it takes a moment or 2 or 3 for the turbo to spool up and make boost....
7.5 or 8:1 is a reasonable static CR for a supercharged engine and will allow the end-user to use moderate to high boost pressures (10psi+) and achieve big power gains..
just my $.02

The blowers he is looking at are all centri's; the only roots style blower that is available for our cars is the 122 magnacharger sold by LME. 9.5:1 is a good start since those centris don't make hardly any boost down low at all. Seem like I am always disagreeing with you, nothing personal, he just isn't talking about the same type of blower that you are.

[Frost]

Well did you hear what that fukin F1 sounds like!! lol Zboner posted a clip on how it sounds and it sounds awesome but for cruises and around the streets i think it might be alil too loud.... anyway to hush it abit?? lol And with the 408 i am looking for 9.5:1CR so i was thinking -28cc dish pistons with the afr 225 66cc heads to bump the compression up am i headed in the right direction??

I know what it sounds like; I have tuned a few and one of my best bud's has one on his firehawk

[NeeD4SpeeD]

I know what it sounds like; I have tuned a few and one of my best bud's has one on his firehawk

It sounds awesome... Thats 4 sure... i just hope that it's not too loud because your totally right that i should buy the F1 first off instead of buying the D1SC then switching it... Its a smart move

[NeeD4SpeeD]

I know what it sounds like; I have tuned a few and one of my best bud's has one on his firehawk

Do you personally like the F1 since youve been around a few? How were the dyno reslults on it, making good power from idle?

[Olde Skoole]

The blowers he is looking at are all centri's; the only roots style blower that is available for our cars is the 122 magnacharger sold by LME. 9.5:1 is a good start since those centris don't make hardly any boost down low at all. Seem like I am always disagreeing with you, nothing personal, he just isn't talking about the same type of blower that you are.

no sweat man....I was under the impression that a centrifugal blower is of the positive displacement type.however i still believe that 8.5:1 is tops for a blown motor...come'on and put your dukes up

[Frost]

Do you personally like the F1 since youve been around a few? How were the dyno reslults on it, making good power from idle?

My friend's hawk (http://www.fquick.com/garages/Pontia...awk/2002/5200/ though that page is a bit dated) went 9.30s in it's shakedown passes at 148MPH with his 402/F1 9.5:1 SCR driving a 4l80 overdrive. Real street car too, can keep A/C with minimal work. Made 811rwhp and 744rwtq at 17-18ish psi. Builders like EPP who are exclusive STI distributors and build these setups everyday almost always go with a 9.5:1 SCR. Bob's bumper-dragger on the front of GMHTP is a 402/AFR225/mild-ish custom cam that use on a lot of FI/F1blower went bottom 9s and is also 9.5:1.

A 9.5:1 forged 347 with a d1sc can make 700rwhp with good heads, meth, and pump gas.

[NeeD4SpeeD]

My friend's hawk (http://www.fquick.com/garages/Pontia...awk/2002/5200/ though that page is a bit dated) went 9.30s in it's shakedown passes at 148MPH with his 402/F1 9.5:1 SCR driving a 4l80 overdrive. Real street car too, can keep A/C with minimal work. Made 811rwhp and 744rwtq at 17-18ish psi. Builders like EPP who are exclusive STI distributors and build these setups everyday almost always go with a 9.5:1 SCR. Bob's bumper-dragger on the front of GMHTP is a 402/AFR225/mild-ish custom cam that use on a lot of FI/F1blower went bottom 9s and is also 9.5:1.

A 9.5:1 forged 347 with a d1sc can make 700rwhp with good heads, meth, and pump gas.

Your boys car is badass man!!!! Doesnt have much suspension work done to it how does it hook?

And i think you have throughly convinced me to go with the F1 Procharger and i was originally going to stick with 9.5:1 and you just reinforced it so thank you.... With the 408 and the F1 with all the other crap i would like it around 750/750 i dont think much more is need then that but i would assume i would need to drop my 4.10s and pick up something with a wider gear ratio cuz then it would just be impossible to shift with 4.10s and 800hp lol

And he's on a stock tranny 2!!!! Impressive its M6 and can still cut 9.30s..... Yup im going with the 408 and F1

[Frost]

Your boys car is badass man!!!! Doesnt have much suspension work done to it how does it hook?

What? It has a billingsley fabbed 9" with an extreme drag anti-sway rear setup welded to the unibody and all chrome-moly tubular rod ended stuff like Spohn rear LCAs and PHB, BMR tubular K-member and tubular upper and lower A-arms, and a custom billingsley TA. Oh yeah, it has the big boy MT radials on bogarts as well.

It's a really nice ride.

[NeeD4SpeeD]

I was going by what it said on the web site and i see he left ALOT out lol... It is a REALLY nice ride!! I see he has the front mount on the F1... I think the high flow twins look better cuz its 2 pipes but i kno u get more from the front mount...Car is setup real well whats the 60'

[Frost]

It went 9.3x on a 1.36 60' during shakedowns. Unfortunately, after about half a dozen passes it lost the belt, which means the alternator dropped off, and even the 3 Walbros and meth feeding it couldn't keep up with the demand the rest of the car took on the battery and it went lean and lifted the heads. Didn't damage the engine, but it convinced him to pull that pretty new 402 and have an ERL 6-bolt 427 shortblock built and moving to 6-bolt heads. Since that will take more than the F1 can make, he is talking about TWIN 76mm TURBOS! That's two of my turbo, and good for 2400-2500 flywheel HP!! Insane.

[NeeD4SpeeD]

It went 9.3x on a 1.36 60' during shakedowns. Unfortunately, after about half a dozen passes it lost the belt, which means the alternator dropped off, and even the 3 Walbros and meth feeding it couldn't keep up with the demand the rest of the car took on the battery and it went lean and lifted the heads. Didn't damage the engine, but it convinced him to pull that pretty new 402 and have an ERL 6-bolt 427 shortblock built and moving to 6-bolt heads. Since that will take more than the F1 can make, he is talking about TWIN 76mm TURBOS! That's two of my turbo, and good for 2400-2500 flywheel HP!! Insane.

DAAAAAMN!!!!! TTs it just too much for me i think if i could break 9s and have an excellent street i would be very happy.... And i see that F1 is very high maintinence as far as all the supporting parts it needs....3 walbros and still leaned out!!?? Thats just crazy!! Hopefully my 408 could handle the 750hp i wanna run through it cuz i dun think i'll need more that that i wanna be around 9.6 and a 1.50 60' which i think is pretty reasonable...And that is a big operation and a shit load of money to re-do everything and switch the block and move to 76mm turbos.... Yea im hoping to get it right the first time with the best parts so i dont have to do it again...

BTW where does your friend think hes going with 2500 FWHP LOL