Dynamometer Results & Comparisons - 408 Low Results

Details: 408LQ4 Mahle -12cc dish pistons (.018 -.020 above deck), 10.93:1 SCR,
PRC Stg 2 Ls6 heads, 64cc chambers .660 dual springs,
kooks 1.75" LTs,
LTD True Duals w/ DynoMax Race Bullets
Catless, 42lb green top SVO injectors
gm mls .055 headgasket
Scat 6.125 rods
Scat 4" crank
242/246 .613 .614 113 + 2
Ls7 Lifters
Tsp Oil pump
Asp 25% UD
Monster Stg 3 Clutch and flywheel kit
moser 12bolt 4:10s
Fast 90/90
Volant Twin cone Fbody CAI
85mm Maf (76mm Maf used after 85mm Failed out during 2nd Dyno Run)
Steel DS

Car is a 2002 M6 WS6, dynoed on a dynojet 248h. Dyno is a bit tough, G6x3 cam, 1.875" Kooks, o/r xpipe, Ud pulley, fast 102, cold air induction CAI, M6 2010 LS3 Camaro put down 483/445wtq on same dyno.

Not My car, but a friend of mines. (Might chime in) I did not tune the car was just reviewing the graphs and logs. Also have the HPT file.

Graph looks smooth and power looks good Just not as high as expected

Car was tuned at Dynosport (About 600+ miles on engine)

Best pull was made with 23* of timing, Pull with 444whp was with 28*

http://i245.photobucket.com/albums/gg48/06x6spdGTO/408Dynosport28.jpg

Torque looks decent for your setup , but i would have expected more hp, heads and intake are probably hurting u a bit . Bigger intake like a fast 102 and at least a trickflow 225 would definently get u closer to the 500 mark

Just wondering why numbers are soo far down from a similar setup like this one:

http://ls1tech.com/forums/dynamometer-results-comparisons/462218-stock-headed-408-468-460-w-ls6-pacesetters.html

With a stock LS6, Pacesetters, Stock 241s, and damn Near same cam, compression. Biggest difference is pistons

Torque looks decent for your setup , but i would have expected more hp, heads and intake are probably hurting u a bit . Bigger intake like a fast 102 and at least a trickflow 225 would definently get u closer to the 500 mark

You think swapping to TFS 225s and Fast 102 over the Fast 90 and PRC CNC LS6 heads are worth 40whp or more????

I would think it would make 40+ more than it did.
There are no misfires or knock?
How many miles are on the 408?

Maybe try a Speed Density Tune instead.

over 650 miles on the motor. No Knock at 23 or 28*

No misfires

AFR looks in line and was measured at the exhaust tip with standard DYNOJET Sniffer

If u decide to go to a different set of heads , go ahead and get a custom cam ground for the heads and your setup....I also agree on the SD tune, lose the maf

Can you post the log files?

Only had some still images of the log. The tuner didnt save the full scans

mill the heads .030 ull still clear PtoV, u have pretty low compression for the setup u have. it should easily clear 520 rwhp

Dont think the intake will seal up since the block has been decked .020 - .030, but I could be wrong......

heads are killing it and maf didnt help

tried the 85mm MAF before it failed out. Made 440/433

finished tuning it on the 76mm since it still worked

Here it is on the 85mm:
http://i245.photobucket.com/albums/gg48/06x6spdGTO/408_85mmMAF.jpg

Was the cam degreed correctly? Any misfires being recognized? This setup even with those heads should easily be in 470-480 rwhp and 450-470 rwtq IMO. The heads and intake are a restriction, but not nearly enough to equate for the power loss your friend is experiencing.

Cam installed dot to dot. its on a 113LSA set on a 111ICL or 113 +2 as per comps final inspection.

I dont understand why all the decking on block piston selection and head cc ! Not being a ass just curious why you did it this way ! That is a shit load to be stickig out the block ! I seen them set low ! And seen them .008 out never that far though!
I mean is there a point where to much isnt od ?
valve angle and geomtry intake not fitting?
I am just asking is all and i get 11.35 on compression

its close on # if you ask me ! rear end and maf setup is choke point !

Like I posted on LS1GTO, you need to address your entire intake setup along with the headers. Even though the cam and heads are less than ideal, it is still a 408 and still needs to breathe. You need a 4 inch intake tract, meaning 104mm Lid, 100mm MAF (or a 4 inch coupler if you go SD), 102mm TB and intake. Also the 1 7/8s headers will help you out a lot too. The numbers also look pretty dead on to me. You are running parts that would choke a 346 running that heads and cam setup, adding 62 cubic inches will only worsen the losses.

I dont understand why all the decking on block piston selection and head cc ! Not being a ass just curious why you did it this way ! That is a shit load to be stickig out the block ! I seen them set low ! And seen them .008 out never that far though!
I mean is there a point where to much isnt od ?
valve angle and geomtry intake not fitting?
I am just asking is all and i get 11.35 on compression

I DID NOT DO This BUILD!!

I suggested running the Wiseco K394x3 -8cc piston at 0 deck to .004+. Was told that those pistons were around $150* more for a full set of 8 than the -12cc Dish MAHLE.

When I heard about the piston being run that far out of the hole I suggested NOT to. ******** Engines (Builders for this setup) Stated that they run pistons out of the hole all the time for the race engines and that it would make the car have more power with less timing. They also took a little time to take a dye grinder to the valve reliefs on the BNIB MAHLE pistons to "Knock the edges down to combat hot spots".

My friend wanted Blueprint to do the build, the heads that were used came off of his old LS1/MS3 setup. As well as the Intake, TB, Headers and he wanted to reuse his old stuff to save a few $$. So I wasnt going to argue with him or the builders. They were set in there ways to running the cheaper piston and .020 out of the hole to get better compression without milling the heads.

Only thing I can see different between this build and many others (Some have even used stock 799 heads with smaller cam) is the piston selection and how far the piston is running out of the hole.

For the top end parts used on this car there is NO reason it shouldnt be over 460whp.

FAST 90/90 has been used on multiple 402/408 builds with great results. LS6 heads STOCK have put down better numbers on a mustang dyno on other 408s.

Compairing flow numbers alone take into consideration that the LS6 heads are normally measured on a 3.900" Bore plate while ALOT of other heads are measured on a 4.0" plate.

Still open to suggestions. But for the amount of money being suggested in (FAST 102/100mm MAF/104 Lid/Trickflow,AFR heads/ 1.875" LTs/Retune) you will be looking at over $5K to gain maybe 40-50whp! I would hope a Trickflow 225 or AFR 230 setup with everything else listed would be at least 510-520whp. Guess it means this one is only about 70+whp shy ~~

Its not like he is going from stock LS6 intake/Tb/241's to a Trickflow/FAST/Big Mouth setup. Just my .02cents

Still open to more suggestions


Headed back to the dyno today with a 02 firehawk (PRC 227, SNL V.4 cam, FAST 102/102, FTP 104 Lid, 100mm MAF, SLP 1.75" LTs, STOCK BOTTOM END LS1, Moser 12bolt 3.73's) that a friend and I have been working on for awhile.

(Same Dyno as this 408 was on)

Considering that my Forged 347 with ported (NOT CNC'd) stock valved LS6 heads, FAST 92/90, 85mm MAF, 1.875" Lts put down 463/416 on the exact same dyno with the 233/239 .598 .603 113LSA cam. 10.7:1 SCR

Then do the intake only and see how much you pick up. Again remember that on your 347 the fast would have shown double digit gains by itself, the gains on a 408 would be compounded

Well for comparison sake got back from the dyno with the h/c/i LS1 firehawk. Through his 12bolt and 3.73's we ended up with 453/420wtq SAE. Same Dyno 4 days later.

http://i245.photobucket.com/albums/gg48/06x6spdGTO/2012-05-20_12-29-30_657.jpg

found another close 408 setup with the smaller 243 Stage 1 LS6 heads, slightly larger cam, FAST 92, Moser 12 bolt, 4.10, 402 11:1 SCR:
http://ls1tech.com/forums/dynamometer-results-comparisons/970307-tsp-402-w-ms3-stage-1-ls6-heads.html

You suggestion would have been better idea on the build ! There where looking for a good quench should have just used smaller head gasket and saved the decking that same setup with piston on top of block at 0 and .040 would have be same thing with same piston ! Minus that far out of the hole and cost to do a foolish thing like that !

The stage two heads will support 500 i have seen it before ! 408 m stix 4 cam and ls6 heads 511 hp 492 trq

The stage two heads will support 500 i have seen it before ! 408 m stix 4 cam and ls6 heads 511 hp 492 trq

I was under the same impression with the heads. As for running the piston that far out of the hole, correct me if Im wrong, but isnt this setup kinda screwed for adding some spray??? Would it cause the piston to look like you ran a torch down the side of it and be a huge risk to the ring land?

would boost be a decent Idea or would the same risk apply???

Just looking for other options here to get his power up.......

Of course, AFR/TFS heads, better headers, and a FAST 102 would probly show some slight gains.

Guys,

The OP PM'ed me bringing my attention to this thread so I thought I would respond in the open forum to share some ideas

I would advise checking cranking compression immediately.....

Start with the basics

If that doesn't look right it answers alot of questions immediately.....if it does look right it makes the answer more challenging (but never impossible) to find.

The fact your making stock cube torque figures (and HP for that matter) on a dyno other cars have rolled kind of what you might expect (ruling out a super stingy dyno) is obviously troubling.

Like I said....start with the basics....cranking PSI gives a good idea of the true compression ratio and whether the cam is in correctly.

I urged someone else to do this recently and his CCR was reaaaalllly LOW (like low 100's). He took his engine apart to find out the pistons were down the hole like .050 (they were made for a crank that had a longer arm!)

Anyway....the cranking compression immediatly lead him to take apart the engine ad see whats what. If your CCR is strong then you have to start considering conventional airflow related restrictions that could be holding you back but you need to check the CCR first and check every cylinder btw to see how even they are across the board.

Keep us posted!

-Tony

Thanks for the insight Tony! Will pass the word along and see if he can get it checked out in a timely fashion!

I DID NOT DO This BUILD!!

When I heard about the piston being run that far out of the hole I suggested NOT to. Blueprint Engines (Builders for this setup) Stated that they run pistons out of the hole all the time for the race engines and that it would make the car have more power with less timing.

WTF was blueprint engines thinking running the pistons that far above deck! Or even decking the block that far?!?

Well guys,

Dont know how to say this but the mentioned engine building company has asked to have their name removed from this build and anything to do with this engine.

So how do I word this,

The engine was built in a storage shed with a couple of cresent wrenches and a file, a gas powered belt sander was used to deck the block and an old ice auger to bore it.

A couple of average joes through it together.

Still looking for answers, for whatever the hell thats worth.......

Will post the cranking compressions result as soon as the owner gets them from the ford dealer!

F-A-I-L!

If you ask me this whole engine was doomed from the start. The owner don't know shit about engines, he just had the checkbook. It is his fault for not using a little feature we all have come to know as the "SEARCH" function before deciding what he wanted to do. The builder is brain washed by an idiot that thinks he knows all when it comes to building engines so he just did what was suggested to do. That guy could learn a thing or two while he's trolling around here worrying about his image. And last but not least I would just drive the damn thing the way it is or start over from scratch.

If you ask me this whole engine was doomed from the start. The owner don't know shit about engines, he just had the checkbook. It is his fault for not using a little feature we all have come to know as the "SEARCH" function before deciding what he wanted to do. The builder is brain washed by an idiot that thinks he knows all when it comes to building engines so he just did what was suggested to do. That guy could learn a thing or two while he's trolling around here worrying about his image. And last but not least I would just drive the damn thing the way it is or start over from scratch.

:usa:

Cranking Compression Ratio:

With the throttle blade cracked open while cranking (Front to Back)

Drivers Side: Passenger Side:
195 200
198 200
200 198
200 198


Pushrod length was verified to 0 lash then a turn and a half, with about .090 preload on LS7 lifters

Cranking pressure is good....about what I would expect....and thats bad because now you would really have to start digging into things.

Are you sure this engine is 400 CID??....LOL

No easy answer from here....you will either have to just suck it up and drive it or take it apart and check everything over to make sure all of it is up to spec.

Not to many other choices the way I see it

Good luck....if you guys decide to "dig" let the rest of the community know what you find.

-Tony

Cranking pressure is good....about what I would expect....and thats bad because now you would really have to start digging into things.

Are you sure this engine is 400 CID??....LOL

No easy answer from here....you will either have to just suck it up and drive it or take it apart and check everything over to make sure all of it is up to spec.

Not to many other choices the way I see it

Good luck....if you guys decide to "dig" let the rest of the community know what you find.

-Tony

Thanks for the help tony,

This seems like a steep rut to deal with. I guess its up to the owner now on which route to choose. Both seem pricey- But if this was cheap everybody would be doing it!!! Gotta pay to play