What exactly does your combination consist of?

Cubes, cam, heads, exhaust......tell us more about your combo.....maybe 425 is a typical figure for the mods you are running or maybe its very light and in fact 480+ is closer to what someone might expect or typically see.

I may have breezed over this thread too quickly but I didnt see a rundown of the combination in question....I think that would lend a cue to the dyno numbers that everyone is pondering over. I would also suggest strapping the car to a different dyno in the area and see how a third data point compares.

Of course trap speed will always give away the real bottom line (assuming we know what the car weighs) but I didn't sense you were taking the car to the dragstrip any time soon.

-Tony

EDIT....Just noticed its a stroker.....what size and how much RWTQ did it produce? Posting a copy of the recent dyno graph would be very helpful as well

 

It's a 402 and on the A&A dyno the #s were 486 rwhp& 473 rwtq
local dyno 425 rwhp & 410 rwtq.

...and I do not know how to post pics or attachments on this site-sorry.

....and I have never raced it. I have not even launched it hard, I occasionaly will mash the gas pretty good. It is a dd .

The short block is a factory LS2 that was stroked out from 364cid to 402cid. It has been balanced & blueprinted, deck honed, and the entire rotating assembly is forged. As a starting point, I used the offering from A&A (refer to that sheet that was in the package I supplied you... with the Post-it notes on the back). It has flat-top (high compression) pistons, Clevite bearings, Diamond rings, ARP studs, and Comp Cams 228/232 .581/.588 114 LSA +4. In English, that means the intake/exhaust duration is 228/232, intake/exhaust lift = .581/.588, Lobe Separation Angle of 114 (lower numbers give more lope, but you can't go much lower than 114 with an automatic transmission), and 4 degrees of ground-in advance. The intake system is upgraded from 78mm (stock LS1) to 90mm, using an OEM LS2 throttle body and FAST-90 intake manifold. The cylinder heads are AFR 205's that have been ported. The valve springs are whatever AFR uses. Tony Mamo is a designer at AFR and a CF member - he could probably give you specifics. The oil pump is stock LS2 that has been ported. The oil pan is stock LS1, so it takes the amount of oil specified in the owner's manual. The transmission is an FLT Level-5, with a Setrab transmission cooler. The cooling system has a 170* thermostat, the fans have been programmed lower to take advantage of that, and the system is filled with a 60/40 concentration of distilled water and universal anti-freeze (+ a can of 40Below). I don't know the brand of the universal anti-freeze, but it can be mixed with the red (Dex Cool) or green anti-freeze -- it's what Charlie Williams uses at RPM. The headers are LG Pro long-tubes that have been thermal (ceramic) coated. The hi-flow cats are by Random Technology. I selected the LG headers because they were the only top of line units that used a slip-fit connection to the catback... meaning you don't have an exhaust flange to possibly catch on a speed bump. The brakes are stock with stock pads up front and Hawk HPS in the rear. Brake fluid is Wilwood EXP 600+ (DOT 4). The tensioner pulley (up top on the passenger side of the serpantine belt) is a stronger billet unit made by RPM Motors. The idler clutch on the serpantine is GM factory equipment - it was a unique feature of 2004s with automatic transmission. The plug wires are MSD, which are nice because they can be formed into any shape and routed away from sources of heat. The air cleaner/intake is a Halltech Stinger using a K&N filter. The fuel injectors are GM 42lb truck units that have been flow-matched (stock is 26lbs). The coilovers are Pfadt 12-way adjustables. The rear-end ratio is stock (but optional) 3.15, and the output shafts are stock. Final compression ratio is 11:1

 

That's good to know....

Listen....something is either really wrong with your current dyno figures, you have an issue with the engine, or someone stole your stroker and installed a stock displacement shortblock in its place. Your numbers look like a 346....with the torque output sealing the deal. Even weak larger engine combo's that dont make alot of RWHP, still make decent RWTQ because torque is a direct function of displacement.

Something is astray here.....you may even have a bad converter robbing you of a bunch of power but Im just reaching at straws trying to think what could be wrong in an engine that seems to run fine based on your input.

Are you sure that an A&A stroker is under your hood?.....LOL

Posting the dyno curve would be very helpful....get with someone that can. Take a picture of it and email it to me and I will look at it and post it myself. Send the pic to tony@airflowresearch.com The bottom of the curve would also help in evaluating the engines condition and Im curious if the lower torque figures also look like a 346!

Get to another dyno.....its worth the $75 to strap it down and get a few pulls to confirm your latest numbers.

-Tony

 

I just scanned and e-mailed you both dyno sheets-Thanks

 

sent them again

 

I hope you find the issue

 

me to.....it's starting to get very very interesting :

 

After corrosponding with the builder/installer/ tuner, he is confident that once the convertor is "for sure locked"(no slipping) also he sees a timing issue that needs addressing (knock retard) on my latest sheet but thinks after that is resolved the curves will be very similar, again.

I do not know how to post the dyno sheets on the forum or I would.

My local tuner and I both agree that the car runs & pulls strong?

So the saga of the missing 60rwhp is calmer but I will continue to pursue those missing lil' horsies and will update this thread when something new is brought to light.

 

Sign up for Photobucket.com to host and post pictures

 

go to tinypic.com.
upload the pic
then there is a "message board" or something similar link given in a box. Copy it and paste the link into a message here
picture will show up

Peter

 

OK, I'm late coming to the party and just found this thread (I cheated... Danny PMed me and then I went searching). Tony, he said 425, not 325 rwhp. If 425 at the rear wheels is a stock 346, then I wasted a bunch of money lol. Justing yanking your chain. You've seen this car and know what it can do.

Not that it is relevant to the missing hp, but I just noticed two omissions in that build spec you are quoting. First, the front rotors are StopFORCE units, not stock (the front pads are stock though). Second, there is a Vigilante 2400 torque converter in there (but it doesn't account for the hp loss because it was there for initial build as well). Hang in there Danny. We'll get to the bottom of this.


Hmm... maybe I need a new avatar.