Investigating into setups pays off. I'll always be the first one to point that out. Shoulda have listened to my own advice when checking into cyl heads a few years ago. I got some flow #'s off the net this morning and plugged 'em into desktop dyno and got some scary results.

My setup is a 355cid block with Sportsman-II heads, vortech supercharger, slp cam, and other bolt on goodies. Compression with the 72cc sportsman is 8.96:1.

Combo Induction HP / Torque
--------------------------------------------------------------------
L98 Heads - 10.40:1 N/A 380@5000 / 456@3500
<B>SP-II Heads - 8.96:1 N/A 364@5000 / 438@3500</B>
SP-II 64cc 9.72:1 N/A 379@5000 / 452@3500

L98 Heads - 10.40:1 Vortech 499@6000 / 540@3500
<B>SP-II Heads - 8.96:1 Vortech 471@5500 / 521@3500</B>
AFR-190 - 8.62:1 Vortech 542@6500 / 528@4000
SP-II 64cc - 9.72:1 Vortech 493@6000 / 537@3500

The BOLD setups are what I've actually ran. The rest is tested in DD2000.

L98 heads produce the most torque, AFR heads produce the most HP. The SP-II arn't doing a whole lot for me in 72cc form. 64's would have got me about 15hp/ 14tq N/A, and 22hp / 16 tq
under boost.

I'm running 8psi right now, but it doesn't seem any faster than when I was running 6psi.

Comments?

-- Joe

 

Interesting..

Cam specs are: 280/288, 224/230d @.050 .502/.510 lift

THe above chart was all simulations with .050 inch cam selected.

If I change the cam timing to seat to seat, I gain tons more HP with each combo of head.

I.e,

.050 " timing:
SP-II Heads - 8.96:1 Vortech 471@5500 / 521@3500

Seat-to-seat timing:
SP-II Heads - 8.96:1 Vortech 546@6000 / 506@3500

So it calcs more HP, but less torque? wtf?

-- Joe

 

first off dd2000 is unaccurate.so all these numbers u posted are pretty far from the truth except i guess the ones u posted in bold.going from 6 to 8 psi is not a big jump, well not enough for u to feel something.

dave

 

Actually I would have thought that....BUT After reading this post I gathered up all of my actual numbers and put them in. ( I flowed my heads, had a cam ground, I built the motor) I entered all my true numbers exactly. The DD2000 has me at 375crank hp at 6000. When we dynoed it without my blower hooked up i made 304rwhp at 5800. Thats pretty close. I don't have any specs on my p600b or I would try that also. I guess its like any other program, its only as accurate as the numbers you put in.


http://www.turbotime.us/gallery/bigtime01

 

no offense but desktop dyno 2000 isn't accurate enough....

when you plug all your info into something like engine analyzer pro than get back to me

 

I think you are missing the point here. I was just stating that after I put all of my numbers in it was actually closer than I would have believed. All of the engine programs are only as accurate as the info you put into them. If you use the programs to check changes and forget about total power, I believe you can learn some things about engines and what they want. I build my stuff from what i have learned over the years NOT from a computer program. I still believe if you put all your REAL numbers in (not the ones the program offers you) It will be close. Allot closer than you would want to believe. Obviously it does its computing on perfect conditions (air,fuel,timing).
Just my $.02

http://www.turbotime.us/gallery/bigtime01

 

I dont really have issues with your bigtime but i do with anesthes

the problem is that those combos all have different compressions and i dont know what else

He says that the L98s produce the most torque and in reality it really isn't the L98 heads producing the most torque, its because that combination has the most compression

Also notice the AFR test....the compression is pretty low and that it produces the most horsepower at less torque but also notice he is comparing that to the L98 test which peaks 500rpm lower and is only up 20ftlb of torue

Too many different variables to get anything out of it really

NOW

if you did that test all within a 2 day period with various different heads with every other variable being the same you'll find honest interesting results and i'll tell you right now that they will all make the same amount of horsepower and torque (well pretty damn close i'd guess within 2% of each other) just at different boost levels.

As for the n/a tests that is going to depend on combo because each of those heads needs a different cam to be optimized in all honesty

 

I understand, he 'anesthes' just needs to get his numbers in order.

 

I think the lesson learned is this:

1) Sportsman-II's don't flow enough for 11s
2) 8.96:1 is too low a starting compression for a Vortech a-trim
3) I shoulda bought a head that ran around 9.3:1 and flows
around 260i 190e. Such as the AFR-195S (part #1034)

It may be possible to make 600hp with that head, and the rest of my setup.

-- Joe

 

very much incorrect....in HIS test yes but this is not the case in the real world. i have a friend with a 355 with 10.5:1 that is going 10.80s with a nitrous cam in it and on the spray mid 9s

There was also a twin turbo motor (355) that was built using sportmans IIs with NO PORTING and on 24psi it made almost 1000hp

many many more examples, these heads work well for the price

i can't comment on this because i dont know the compressor map for this supercharger, if had the map i could comment on it

head selection in a blower setup (street type) doesn't really matter what you run. All a higher flowing head is going to give you is the same horsepower at a lower pressure level. Now if you wanted to compare say the design of a raised runner 23* head versus a standard and how the better airflow path can lead to more horsepower potential, well that is a different story. But, in general, the only thing a bigger intake port and higher flowing head will do in a boost setup is get the same amount of horsepower at a lower psi rating on your gauge.

For example, take that sportman II setup that made almost 1000hp @ 24psi and put on my ported track 1s and you'd reach just about the same horsepower at about 19-20psi. Thats about it

 

Thats interesting. Whats it weigh?

http://www.vortechsuperchargers.com/...-trim_map.html

I'm running a 8" crank and 3.33" s/c pully.. Shows 8psi on the gauge.

I understand the logic, but wouldn't a less restrictive system put less load on the blower, and take less power to spin it?

-- Joe