DavisC5C6

Long story (short is #12 lines after).

I plan to rool cage (6pts) my car to run faster on strip (10.4 now boost only with #900hp thru MN6 on E85, but local track law changed), and want continue to road drive it (a lot).
Also want perform in 1/2m (200mph) and run low 8s a fexw time (w/nitrous add).

For now, have cam who kill my mpg (#.640 lift)

So, i plan :

• swap aluminium block to the low cost GM LSX (aka LY6 + dod delete + LS9 head gasket),
• stay with LY6 ci (364), CR (9.6:1), spring (as they are the same as LS2/LS3/LS6 and LS9 cam capable), valves, rocker, piston, rod, cranck
• keep LS3 style head (LY6) and port and handwork it,
• going procharger F1X (as it's the biggest i can put on braket/10 ribs direct drive i already have), 8" lower, 4"125 upper, maxout @#6900rpm,
• put a stock LS3 intake manifold (best bang for the buck to take a lot of psi),
• keep my 2" header/put my old 7.4 hardener pushrod/buy LS2 chain&damper and some lifter.

And... asking for the cam...

1) RWHP result with little LS9 cam ? (but biggest eom GM cam/best MPG) ->cheapest option
2) RWHP result with spec cam&average spec (with good HP/good MPG goal) ->and does #$1k5 more for cam/springs/lighter intake valve is good option ?
3) RWHP result with spec cam&average spec (with best HP/streetable at 2k5rpmgood MPG goal) ->does #$1k3 more again for low profile intake and 102TB is an option ?
(going stroker 421ci can be an option, but as it's another $2k6, my goal will be +1500FWHP/1300RWHP)

My math :

• for 1/4m goal boost only, i need 1200 HP,
• for a few 8s 1/4m boost w/nitrous, i need 1500 HP,
• for break 200mph (boost w/nitrous), i need 1500 HP,

so... 1200 (plus 300 shot just a few time) should do the job,
(1200... FWHP i presume as i use wallaceracing calculators, so 1025RWHP)

Detailed info resume (as asked in another post)
Bore : 4
Stroke : 3.622
Compression Ratio : 9.6
Valve size : 2.165 intake (1.590 exhaust)
Runner Volume : 257cc intake (87cc exhaust)
CC : 70
Head Flow (stock LS3) : https://www.speednik.com/files/2017/...8_16-22-03.jpg
Head Flow (handported LS3) :

• LIFT....... 100 200 300 400 450 500 550 600 650 700
• Intake...... 71 148 222 275 297 317 332 343 350 323
• Exhaust... 51 108 152 190 208 217 223 228 231 235

Engine RPM usual : 6600 (96% of the F1X max rpm)
Engine RPM a few time : 6875 (100% of the F1X max rpm)
Fuel : E85
HP : 1200FWHP
Boost : ?
->F1X is 38 psi max rated
->I saw 8.3" lower / 4.0"upper / LME 429 C7 hit 26psi w/1291rwhp@6k3rpm / 10ribs / 10.5:1 / ported CNC LTx heads / 235/248 118LSA / LTx Intake / 2" LT, MN7 / 1402rwhp/E85
->So, a max of #30psi @6k5rpm w/8'' lower -4''125 / 376ci with (impossible) same flow (cause less head/cam/intake/CR and tech -LT vs LS-)

Full LS9 Cam Spec :

• Lobe lift (inches): 0.328/0.325,
• Valve lift (inches): 0.558/0.553 (1.7 rocker ratio),
• Duration @ 0.050": 211/230,
• Lobe Separation Angle (LSA): 122.5,
• Degrees of advance: 0,
• Valve timing @ 0.050" tappet lift :
  • Opening intake -17.0 BTDC/exhaust 57.5 BBDC
  • Closing intake 48.0 ABDC/exhaust -7.5 ATDC
  • Overlap angle -24.5

Best regard

ddnspider

iTrader: (26)

That cam is a terrible choice. I'm all for letting the boost do the work, but get a cam for that specific setup instead of going with a stocker. That said, if you really have 900hp you should be running faster than 10.4. Maybe work on the drivetrain/suspension? Can you post a slip?

DavisC5C6

It's not the reply i expect, my need is the HP i can shot with LS9 cam / 6.0L /9.6:1CR / LS3 hand ported heads and intake / F1X

"That cam is a terrible choice..." :
i know will lost a ton HP vs a spec one... but read me...

A spec for boost/hp will not respect my goal (real daily / e85 / MPG / capable to drive 350 miles round trip and make 15 runs in the drag weekend with only full gas tank and just one or two additionnal 5 gallons E85 portable tank...
So, no need of +1700RWHP as i seen with this F1X, just need 1025/1050 or so (aka 1200FWHP).
But now, if you confirm 100% sure that a LS9 cam will never make 1025HP... we can discus about spec cam

"if you really have 900hp you should be running faster than 10.4"
10.4 was a one shot (be fired by FIA organization as i was 1.6s faster than my category (no roll bar)
i probably can perform a 9.9 (was the original goal with my build, but race rules changed... so... not allowed at al :-( )
10.4 was done on horrible situation (tire/tune/track/air hot)
10.4 is low, but i'm one on the fastest real street driven car on my country (France, in Europe) and some around in Europe (Italy, Spain...)
I'm also in the top 3 (perhaps the 2nd, as i now a Frenc AC cobra around 600ci NA run in low 10 in Santa Pad in England) real street drive stick car
and the fastest LS1 (original LS1 corvette bloc)

FYI, drivetrain and suspension was 100% stock, just a good clutch ;-)

ddnspider

iTrader: (26)

My point is that you can get a different cam that will still be daily driver friendly and make more power with a better power curve. There is also something to be said for not having to run max boost to hit a power goal. As far as ET, people have run mid 10's or better in daily driven street cars with air conditioning. In my instance, I ran my 10.6 at 8 psi in a daily driven 3800lb manual with air conditioning driving to the track. Like I said, you should focus on more than just power.

LilJayV10

iTrader: (39)

This should be entertaining.....

squid

I'm all ears on this one. I've noticed that 800-1000whp TT builds can achieve 30 mpg highway which is better than stock.

But this is a centrifugal w/o backpressure.

I've found no discussion about how the LS9 works. Lingenfelter GT1 cam is still a 122 LS cam.

I look at the LS9 two ways:

• Don't need economy wasteful overlap for improved VE - let the supercharger do that.
• LS9 valve timing is like a Big Cam where the Overlap was massively reduced - the 122 LSA is the sort of valve timing coming from the VVT arena.

I'm looking for engine simulation software that:

• computes turbo backpressure instead of asking for it as an input
• clearly demonstrates the changeover from high backpressure turbos to "NA" cams w/new high eff turbines and low backpressure
• accurately predict engine output with "uncommon" valve timing (what empirical base is there for 122 LSA's?)

G Atsma

I like your thinking....

Corona

Y not just Call in and Have A Custom Cam made.



it's the Logical thing to do ... made Specifically for you and your build not this 💩 talked about. Factory ls9 cam 🤣

Guy goes Builds a Nice engine then wants to use a Factory Cam.... Wow 😲

squid

Has he looked at the Lingenfelter GT9 cam? https://www.lingenfelter.com/PROD.ht...ode=L210150309

215/247 duration @ .050 lift - .629/.656 lift with 1.7 rocker 121 CL

A very long time ago, a road test of a GNX Buick, when they were driving it to the strip with the 5th wheel (!) attached they were getting 44.5 mpg on the freeway if I remember correctly.

We know how to make hp, now it's having you cake and eating it too.