DragSource

I have a really nice eq-length mani sitting at home. . . but I just read something that gave me an AH HA moment.

The problem with the BIG turbos (sc61 hx35 etc) isn't that it doesn't make top end power. . . it's that they spool late.

Would it be wise to sacrafice the beautiful manifold I purchased for the shortest runner mani I can get to aid with spool time.

Which comes into play more in the 1/4. . . the extra mid-top from the manifold, or the slightly earlier spool?

(A little background on my setup) B18B 83MM Sleeved / HX35 / Plans to rev a little higher than your average LS (however high I need to rev to stay in boost) - but on a JG Pro Head and Crower 403's.





Modified by DragSource at 6:11 PM 6/14/2005

1.8tgsr

Also Interested

Sonny

How about a tubular using smaller tubes?

Sonny

DragSource

??? Possibility I guess

I think we would see less gains up high that way, but the spool would come on faster. . . might get to keep the midrange gains of a eq-length doing it that way. . .

I really don't know - hoping to get in-depth.

JdmEKCivic

Some good cams and tuning can carry the power band higher. Also a good set of cam gears on a eq-length cam make major power.

DragSource

I guess when it all comes down to brass tax, what I really want to know is:

Which is more important for hitting low ET's in the 1/4. I don't care about street driving.

A ) EQ Length Mani - giving substantial mid to top end gains, or

B ) Log mani - making less power up top, but minimizing spool time by a small margin (500rpm is what I hear on avearage.

Looking forward to hearing opinions on this.

Muckman

iTrader: (2)

I believe there are much better ways to increase spool than to "downgrade" your manifold. Bigger exhaust is a no brainer. Get an EMS that has anti-lag techniques to build boost off the line. Or you can juice it

Def

Wrap your nice manifold in header wrap and get the best of both worlds.

Turbo-charged

depends on the size of a turbo. on my h22 motor that i have sitting in my hatchback collecting dust......when the motor was originally in a prelude with a T72 turbo on it....it made awesome power and spooled really well all things considered. when i put the same motor into a hatch back.....since i was pressed for time i made a log manifold......it spooled like a turd and lost power big time.

Butcher

maybe it's just me, but isn't drag racing all mid-high rpms anyway? you don't have much worry about spool time save for getting right off the line. after that it's all redline shifts. I would stick with the = length manifold.

drift2004

its not just the manifold that makes ur turbo spool quick, ex. compression
if i were you i would send it to get jet hot, the manifold and the turbo housing, and the intercooler pipes if u can but also what size pipe u use link
https://honda-tech.com/zero...02591 or
this should help you get ur thing to spool quicker

2" piping
1.57 x 2 = 3.14 sq in
300 cfm = 156 mph = 0.20 mach
400 cfm = 208 mph = 0.27 mach
500 cfm = 261 mph = 0.34 mach
585 cfm max = 304 mph = 0.40 mach


2.25" piping
3.9740625 sq in = 1.98703125 x 2
300 cfm = 123 mph = 0.16 mach
400 cfm = 164 mph = 0.21 mach
500 cfm = 205 mph = 0.26 mach
600 cfm = 247 mph = 0.32 mach
700 cfm = 288 mph = 0.37 mach
740 cfm max = 304 mph = 0.40 mach


2.5" piping
4.90625 sq in = 2.453125 x 2
300 cfm = 100 mph = 0.13 mach
400 cfm = 133 mph = 0.17 mach
500 cfm = 166 mph = 0.21 mach
600 cfm = 200 mph = 0.26 mach
700 cfm = 233 mph = 0.30 mach
800 cfm = 266 mph = 0.34 mach
900 cfm = 300 mph = 0.39 mach
913 cfm max = 304 mph = 0.40 mach


2.75" piping
5.9365625 sq in = 2.96828125 x 2
300 cfm = 82 mph = 0.10 mach
400 cfm = 110 mph = 0.14 mach
500 cfm = 137 mph = 0.17 mach
600 cfm = 165 mph = 0.21 mach
700 cfm = 192 mph = 0.25 mach
800 cfm = 220 mph = 0.28 mach
900 cfm = 248 mph = 0.32 mach
1000 cfm = 275 mph = 0.36 mach
1100 cfm max = 303 mph = 0.40 mach


3.0" piping
7.065 sq in = 3.5325 x 2
300 cfm = 69 mph = 0.09 mach
400 cfm = 92 mph = 0.12 mach
500 cfm = 115 mph = 0.15 mach
600 cfm = 138 mph = 0.18 mach
700 cfm = 162 mph = 0.21 mach
800 cfm = 185 mph = 0.24 mach
900 cfm = 208 mph = 0.27 mach
1000 cfm = 231 mph = 0.30 mach
1100 cfm = 254 cfm = 0.33 mach
1200 cfm = 277 mph = 0.36 mach
1300 cfm max= 301 mph = 0.39 mach [IMG][/IMG] [IMG][/IMG]

turtle-eg

Stick with the equal length for the 1/4... You're always in high rpms anyways... plus you gain more top end power from the equal length by letting the exhuast breath better.

DragSource

I'm feeling better about my eq-length already

Sounds like a plan. . .

The HX35 came with a 3 in v-band o2 housing, so I'll probably just use that.

The charge piping is 2" from turbo to IC and 2.5" from IC outlet to TB.

I'll get the manifold coated or wraped so that it doesn't let as much heat out.

. . . and I'll call it a day and finally relax until I can finish the block. . . and this year long project. Then it's going to be off to the nearest Neptune tuner.

Thanks for your suggestions folks.