vmapper

iTrader: (8)

Rundown:

Using AFR 230 v2 heads 65cc - 0.041" gaskets
Brute Speed Blower cam

D1SC - crank pulley 8.1" (8.25) and 3.4" head unit - will take to 6500rpm

What are your thoughts on

choosing -11cc wiesco pistons
-static compression - 9.37
- Dynamic compression - 6.9
-quench distance 0.045

or using -3.2cc wiesco pistons (flat)
-static compression 10.31:1
- Dynamic 7.55
-Quench 0.041

what is safe for pump fuel.
Unknown boost level with this combo.

-not drag driven

does one get the -11cc pistons and just add a bit of timing if need be?
is dynamic 7.55 too much if the D1SC maxed out produces 15psi with this cam/heads?

I would have preferred ~9.7:1 as ideal, but not feasible with the choices at hand.

your thoughts?

eb02z06

iTrader: (18)

That's some serious RPM on that blower-she's gonna make some heat. I made more power by slowing it down-less slip too.

I've done that combo with -3.2cc's alot but used the .051 LS9 gaksets.

800 rwhp all day.

Don't bother trying to get a tight quench with the FI deal, it doesn't work like a N/A deal.

dschmittie1

iTrader: (64)

Diamond makes a -8.6cc piston for the 347

vmapper

iTrader: (8)

diamond 11503 was what I was originally going to go with... so to correct the above, it IS feasible.
AT steel rings seem to be on short order.
Dont get me wrong, they are probably both good products, but Im leaning towards wiseco for the thicker ring land.


- It will be at the upper limit of blower rpm for sure.
Perhaps 3.55 head pulley?

What was your DCR with your 800rwhp setup using the -3.2cc? was meth inj used? * yes.
Oh it just clicked... Arun, - Ontario. - very impressive.

Question though, you used 72cc heads? 0.051 gasket 347. with 3.905/3.903 pn K398X3905 which have a piston to deck clearance of 0 (9.24"block)
I keep getting 9.33:1 static compression. Is this correct?

yelo04goat

iTrader: (11)

have a slight mill done to the heads to bump it up.. if with a 63cc chamber i think your bee around 9.6 or so if i remember right from doing the math over a year ago its like.006 per cc so .012 want hurt much still got a deck that will be .738 thick right...?? thats with a -11 cc piston dont quote me perfectly on this but im looking for the same and its been awhile since i looked at it all...

I8UR4RD

iTrader: (16)

I attempted to have 9:7:1. I figured that was about the sweetest spot for a street strip combo car on pump fuel.

eb02z06

iTrader: (18)

The last D1 we did actually had some Diamonds-I'll have to dig up the dish but I'm pretty sure it was just a flat top with valve releifs and with the 72cc Patriots compression was around 9.75.

Yes it had meth as well, cam was a 230/242 115+3

Also did a 347 with Wiseco -3.2 and stock LS6's and a Novi 2200-which is pretty much a D1SC, it made 800/700 too pretty easy. With meth as well-compression was over 10.1 on that deal.

I wouldn't worry about the quench-I tried it in a FI deal in hopes of keeping detonation away and it didn't help-infact it made it much worse.

3.55 is the pulley I would use-it will make 800 rwhp, the 3.4 will make a bit more torque but the IAT's will get hot and the bower will end up running out of air.

Make sure you run a big BOV as well.

If you want a wider tuning window-run less compression and add more timing, If your ontop of the tuneup all the time and are wise to detonation-run the higher compression.

My testing has shown it pretty much evens out.

I will be running around 9.3-9.4 on my new set up, 365/LSA heads but boost will be 25+. Pump gas and meth.

Your gonna have a fun car on your hands-that D1SC is a champ of a blower!

I8UR4RD

iTrader: (16)

4 bolt by any chance?

Reason I ask is because in the future I may run an f1-x and I am probably going to try and push those numbers. If it pushes water I will sell this motor and go 6 bolt.

eb02z06

iTrader: (18)

Yep, 4 bolt. Never had an issue pushing water up to 1200 rwhp on 4 bolt heads.

I8UR4RD

iTrader: (16)

thats great news.

vmapper

iTrader: (8)

Good information!

I have one Big Red bypass valve.

Do you have the advertised intake and exhaust duration by chance?
The ILC is 112° for that cam.
ABDC would be 47° vs 50° for the cam i selected (though not using 0.06" values) which means I have a lower dynamic compression, correct?


I am curious how different this cam is vs the one I am using.

In your experience, you are suggesting that for WOT power, there is not much difference with lower compression / more timing VS higher compression vs careful tuning.
(other than driveability and mpg)

Also, any specifics on meth?
Alky control?
100% pure or mixed?

appreciate your time to answer these qs

I guess it just comes down to do I run with the -3.2cc piston or the -11... or change up to diamond or change up head cam combo.

vmapper

iTrader: (8)

anyone else have thoughts on running -3.2cc wiesco with 65cc heads ? too much? someone has to have went through this scenario.

I8UR4RD

iTrader: (16)

depends on the tune.

vmapper

iTrader: (8)

I was more curious about the inability to control detonation and end up with very low timing. Meth is obvious for the higher compression.
But is the lower a better route, advance more timing and possibly achieve the same result?

Perhaps just over thinking this.
Run with 10.3:1 static / 7:55 dynamic.

I dont think the D1SC will give 17+psi with the heads Ive chosen anyways.

I8UR4RD

iTrader: (16)

dont worry about the lbs of boost you will see. its just a simple measurement of backpressure. the more boost means that your overall setup flows less.

lets say you run a stock intake on your setup

you make 800rwhp @ 16 lbs

you swap to a fast 92

you make 864 rwhp @ 12 lbs.

That has happened. It was an ls2 intake fyi, but the blower is still flowing the same amount of air. The setup is just more efficient. I would rather push 40-60 more horses than be able to say I run a high #.

vmapper

iTrader: (8)

Perhaps the # was a bad example.
I am aware the boost is a feedback of engine restriction and the number itself isnt the concern. (im spinng the blower as much as it will allow, whatever the number is ..doesnt matter.


It seems to be an illusive answer when it all comes to Dynamic CR and ECR when boost is used (e.g. this case a centri-blower)

The concern I have is choosing a setup, to which the dynamic compression is too much for pump fuel or pump fuel/meth to be most efficient.
As in, having to dump fuel and pull so much timing because of choosing -3.2cc pistons.
Or to choose a too low to have a 'dog' within the drivability range.

Obviously cases differ based on different FI means, but for centri, i would think maintaining higher compression is better, but to what point?