ok i need help getting more power out of this thing. its been a very long frustrating battle that isnt making the builder/tuner or my life easy. im goona have to do my mod list down to an exact T hoping someone sees something. for now lets assume the long block builder who is also the tuner knows what he is doing assuming someone will question him.

2000 camaro, drivetrain is a T56, heavy monster ceramic puck single disc, fab 9 with s-trac 3.89 gears, stock 17 inch tires. this identical drivetrain made 459 wheel and 408 tq on my ls1 with a largish cam, heavily ported 799s, fast intake and supporting bolt ons, so i assume this isnt an issue since those numbers are right where they should be.

on this motor my mods
RED sleeved ls2 4.125x 4 inch stroke 427
standard callies crank/rods with wiseco pistons
ls2 chain with new gears non adjustable, cam was only off by .25 of a degree so we left it
mamo 265s, v2 larger titanium valve version, pac 1207 springs
mamo specced cam, 247/261
kooks 2 inch headers, 3 inch collector, exhaust 3 inch y into 4 inch flowmaster merge, bullet race muffler dumped
crower shaft mount rockers with 3/8 BTR rods, no need for the mantons here since the rockers are adjustable
johnson short travel with axle oiling
lonnies double fuel pump
mighty mouse catch can, pulling from one valve cover and a vent line to the other which goes to the intake
improved racing scraper, larger oil pan with remote filter
ATI dampener, not underdriven, also the heavy version one, the salesman said heavier controls harmonics better than the light ones
mamo ported msd intake, NW 102
NGK tr-6 plugs with grannatelli wires, stock 100,000 mile ls1 coils
maf is a lingenfelter 104 which uses a generic 4/6 cylinder colorodo saturn maf card
fast toys lid, AEM air filter, SSRA intake

 

so we had issues with it stumbling on dyno low and midrange, tried many things until he decided its has to be injectors. buy injectors, stumbling goes away, dips on dyno graph go away, finally get a smooth AFR across the board, this leads us to this dyno, sorry its the only pic i got


so 500 tq is just too low for this thing, id imagine if you include the fact that this isnt an ls7, so no lighter rotating assembly, the tq should be 525 minimum. ruling out drivetrain by what the exact setup made with the ls1, different dyno but still. so we decide to run the pull out more and notice its dropping hard above 6000, so we swap out the pac springs in favor for a cam motions set. he assumed the pac 1207 cant handle the heavier rockers like they could handle the yella terra that tony originally had specced the heads for, still not sure how much heavier these are but thats not important right now

 

sot the new springs he had around that actually he said would be perfect are VSK143306, which google told me is a cam motion part. specs are 1.324" OD double springs, 160 lbs at 1.800, 510 at 1.100. i believe he contacted crower and the wanted like 195 on the seat minimum. with shims he said we are right around 202. so should be perfect. which leads us to more dynoing and more fails. he has now adjust valves twice, removed exhaust and added extensions, unplugged maf, ran without filter and lid, all with no avail. however messing with the maf specifically did something, just not enough. it has a larger honeycomb screen in it which was sitting crooked, so he removed the screen and ran it again, which is the dyno graph below. Red is with crooked screen, blue is screen removed

 

idk what else to try, the intake is reading 97% from 3000 up, throttle is 100%, he has dynoed other cars inbetween that are making what they should, plenty of 600 rwhp vettes been on this thing, hes not really sure what else to try other than go speed density and see what happens. the compression is 195 to 200 on all 8. the shortblock was built by someone he likes and has done lots of stuff with. hes also a fan of stock rockers for power but im not a fan of stock rockers cause i like geometry. i think we need to figure out what is cause the tq to be down before we address the top end. i did see this while searching that i thought was interesting....

https://ls1tech.com/forums/pcm-diagn...er-setups.html

i just wish it made the tq and fell off on top, so much easier to figure that out. i just dont get how its making the same tq as my previous resleeved motor that 500 miles later had 50 less hp and low compression. the only other thing im thinking is a combination of small things, maybe even a crankcase pressure issue? idk

 

What's the compression ratio?
Was the cam degreed?
Have you tried speed density only, no maf? 97kPa isn't great unless you're high DA.
Did you try a pull with out the Y pipe?
Does injector duty cycle match the Dyno numbers?
what do the plugs look like? Everyone firing well?

 

the cam was checked, came in .25 advanced, so we didn't need any adjusting

pulled y pipe put on extensions

plugs were checked before spring swap

I can ask duty cycle question tomorrow

I no 97 isn't great but didn't think it was dogshit

forgot compression, it's 11.75, 93 octane.

 

What did the plugs look like? 11.75 on 93, possibly picking up knock on summer heat? What's your DA? 97 isn't good unless your high up. You may still have an intake restriction.

 

I didn't see the plugs, he did it. hasn't been super hot. I'm in pa so not super high up. he has removed everything in front of TB and it still hasn't really gained so what other restriction do we have

 

I thought you posted that you kept the MAF, only fixed the screen.

 

Hey man.
Something is definitely up there.
You have all the good gear.
At what RPM were you expecting to shift this thing?

 

Numbers seem to be righ . Dont know what you are expecting on pump and a street combo. If the car runs good then forget the numbers. Just run it and see how it does. Are you racing forum trolls or are you actually racing cars?

 

Darths 440 just did 700whp on 93...

 

that was on a jet. You are not making 800 crank out of a 440 street car. Also, take all dyno numbers with a grain of salt. Additionally, suspension is in many instances (not all), more important than power on the street.

 

Does everything lubrication wise checkout? Don't have too much oil in the pan getting whipped up by the crank? The right trans oil? Rear end isn't binding? Pinion angle is where it should be? Axle bearings properly lubricated? Rear brakes aren't dragging? yada yada

 

It did 650whp on a highly conservative Dyno using slicks which eat power. Perhaps you should go in the thread then and explain to everyone how it's not possible. The OP wants a number and feels it's being held back, perhaps help him be constructive with things that might help him reach his goal since he said no mention of suspension or racing?

 

explain on what planet a decent running 427 d oesnt make 400 tq by 3000

 

as far as driveline related stuff, none of has changed other than driveshaft and trans being unbolted then rebolted.....no signs of brakes dragging. he has dynoed other cars in between and all seem to make what they should.

he has ran it with maf unplugged and out of way before new springs, made an ounce better. than he ran without the screen but everything in front of tb in place and that was the blue line on dyno. red line was crooked screen and everything installed.

I think next we try speed density to see if that helps. his next thought is the cam may want more compression....idk. and no I don't have the cam card for u guys to confirm if that's true. he has it for when he degreed it

 

oiling questions, improved racing said way before we built this that the scraper won't work with a moroso deep pan. however he installed it and said he had no interference. so it's still on there

 

Lifter preload/pushrod length as expected?

 

Proper break-in procedure followed with varying load and heat cycles? Compression and leakdown numbers?