LS6427

iTrader: (2)

Whats your basic set-up:

RWHP?
RWTQ?

Meth...no meth?
Pump gas or race gas?
Cubes? bore x stroke
Compression?
Which Block?
cam specs?
Tranny?

Thanks...I might go this route instead of a big N/A stroker engine.

.

Taubr Unit

iTrader: (32)

LS6427

iTrader: (2)

Nice project........I'm just a street car though, full weight, full interior. I want something thats "pretty much" a bolt in set-up. A little fabbing and alterations is ok, but nothing crazy. I must keep A/C too......

.

fatmat80

tsp 347
prc stg 2.5 ls6 heads
9.3:1 compression
ls6 intake
no meth yet...
550+whp/540+rwtq at 8 lbs of boost

Nitroused383

iTrader: (10)

Buddies 04 M6 GTO I tuned, stock bottom end, trex cam, d1sc. 560 / 500 on 9-10lbs, but just ran 10.7 @ 129 mph, full weight in 4200' density altitude. Car runs like dog **** with no meth, 170-180 degree IAT's but with meth its around 60-70 degrees. Goes from like 12.8 with no meth to 10.7 with lol.

https://ls1tech.com/forums/forced-in...t-results.html

NoGo

iTrader: (2)

Numbers in sig.

No meth, just straight-up 17 psi boost on 8:1 compression

Stock block, stock rods (bronze bushed), LQ9 heads, customer pistons.

'Trust'

iTrader: (24)

Old car:
19psi, D1-SC 3.4" pulley, 8.65 crank pulley
808 RWHP
723 RWTQ

Alky control single nozzle kit
91 octane pump
396ci + AFR 205's
9.62:1
98 LS1 block in a 00 WS.6
XP racing blower cam (I was asked not to give out specs)
XP racing built 4L60E

LS1RedZ

iTrader: (19)

754rwhp
707rwtq
Should be better with the new tune.

No meth
93 Octane
370ci
9.1:1
6.0 liter iron block
EPP blower cam
6 speed

Nitroused383

iTrader: (10)

You guys making all this power what kinda times are you running?

'Trust'

iTrader: (24)

I was blowing through my converter, 3966lb car, 1.3 60' off the foot brake, 9.98 @ 130 (converter letting go). Never went back with the new Yank before I sold it.

LS6427

iTrader: (2)

Well thanks for the replies. So...800 RWHP is possible and then some.

So, if I go:

370ci iron block...stock crank & rods
forged pistons
9.8:1 cr
ported AFR 205 heads
ported LS6 intake
93 0ctane
cam...??? Leave that to my builder.
17-19 psi

I should make close to 750 RWHP with a 4L80E?????

How about a 100 shot on top of that? Maybe forged crank and rods if I plan to spray it.

.

NoGo

iTrader: (2)

Couple changes:

Go with the 225 heads.

Go with aftermarket rods. They are inexpensive now.

Drop the compression to at least 9.5:1

Select a cam with little or no overlap - some builders know this, some don't.

The D1's that make 800 HP have a nice inlet into the supercharger and a good size intercooler - ditch the ATI setup.

Z06_Fan

Most will jump right in and say that you should do forged rods right away......
Crank is proven at that power level.

Just a quick thought.......factory rods = free + good ARP bolts = 200 ?
Good forged rod including good bolts = 600 ish

Thats 400 difference.......but motor is already all torn up, so 400 might be cheaper up front.

I say go stock, I want to see these really pushed!

Gluck, have fun

NoGo

iTrader: (2)

I run stock rods on mine. Have been doing it this way since 2004.

However...... a motor nearly identical to mine (with stock rods) came apart just north of 800 RWHP. The motor was a mess after the failure, but I suspect it was a rod that let go.

You can keep them together with stock rods at that power level, but if the motor hiccups you are going to **** a rod out the bottom of the block.

Also, (IMHO) you should bush the stock rod if you are going to use. After bushing, bolts, and machining you are up to about $400. An aftermarket rod, like you mentioned is $600.

'Trust'

iTrader: (24)

4L80's are heavy, I bet you make 700RWHP and change with that setup, 750 will be a stretch with a 4L80E but could be done. I'm with NoGo on most of the rest.




I was on the stock 4.5" ATI Intercoolers. Meth was my saving grace though, IAT's were consistent 160's, meth kit brought them down to never going over 85* after consistent runs.

I'd like to see some higher compression boost builds, if done right, there is a lot of potential for >9.5:1 CR builds. Lots of manufacturers are starting to go that way. Direct injection and high CR boost builds in LSX cars are what dreams are made of!

LS6427

iTrader: (2)

I have no problem going forged crank, rods, pistons right off the bat. I'd rather spend it up front then on a tow to a shop and a rebuild. I also want to hit it with spray so better to go forged from the get-go.

"Trust"....
So, regarding a higher compression build, what should I try? I'll be the guinea pig. I also have no problem running full time race gas, but only 103 octane. There's gas stations all over the place down here with 103.

So is 370ci optimal size? Lets put together the perfect build here and I think I'll go for it.

.

COPO9560

Why build a 370 when you now have a 427??

Could you have LPE freshen up your existing motor with lower compression pistons? The 427 could support a bigger blower and you could put down some serious power with an F series blower.

Bob@BruteSpeed

iTrader: (16)

Here are two using D-1SC's we did back at the old shop that is no longer in business. Bob
http://www.exoticperformanceplus.com...Car.php?car=42
http://www.exoticperformanceplus.com...Car.php?car=54

LS6427

iTrader: (2)

Well, once again, I want to build this thing without having to put my car into a shop for 50 hours of fabbing and reconstruction.....

My 427ci is OLD and tired. Its had a 4.125 stroke in the old original LS1 short sleeves. It needs a rebuild for nobody that wants a powerful N/A only engine.

I want to start fresh with a good iron block.

.

'Trust'

iTrader: (24)

I always thought it would be cool to run 10-11:1 E85 boost motor. Cooling properties of E85+its octane+boost would be sick.

I'd probably stay away from full time race gas if you want to go the gas route, it gets old quick. I had a 101 tune that was 'safe' didn't make anymore power really, but it became a PITA.

I'd build something with a ~4" stroke, good forged internals, pinned mains, thick deck heads, 12 point studs and see what it does. I'm like you to a point, I don't mind being the guinea pig, it's kinda fun. I loved my 396, I just wish my mains would have been pinned so we could have seen what it would really do.

1 thing to keep in mind, if you want big power on the 98, you'll need BS3. The 98 PCM is only capable of 2 bar SD, and you can't just plug/play in a 99 harness. Several of the sensors are different, 3 pin opposed to 2 pin etc. Something to consider.