Tony Nichols

iTrader: (2)

So, this is my first dyno ever, as well as my first engine build (built by me), so im a little bummed at the results. I picked the engine up in michigan a few years back, supposedly rebuilt, ran for a month and spun bearings. I put it to the side and finally tore down for a rebuild this year. The internals were garbage, chunks of cam missing, low spring pressure, collapsed lifters, 40over on some of the mains, and a bunch of other stuff.

So, my rebuild:

20022004 LS6 Cam. I: 204 E: 218. I: .550 E: .550. 117.5. - brand new
12499224 Ls6 valve springs - brand new
LS7 lifters - new
New Crank - reman
New Rods - came with above crank
New Rings
New head gaskets
New head stud kit
New front and rear gaskets
New Oil pan gasket
New Mellings Oil pump
3 Angle valve job
New Valves
New HD timing chain
New Harmonic balancer pulley
New arp and non-arp hardware
180 degree headers
3.5" Intake
Stock MAF
Stock LS1 intake manifold
Stock injectors
Stock 1998 ls1 Tune
12lb aluminum flywheel
Ls6 clutch kit
steel driveshaft
4.10lsd
275/30/18

I made a whopping 285hp/286tq Im not sure if it has something to do with the stock tune or something else. Also, when the camshaft was installed, the machinist said that the cam should be installed one tooth off from the factory setting, but everyone else said he was incorrect because he specialized in old school small blocks. I reinstalled the cam to factory spec, not to risk damage. Any advise.

Silver408z

iTrader: (1)

I understand being let down on your results but really for your setup you made about what you are supposed to. You have a stock ls1 with a ls6 cam. Your headers are probably something you don't have much selection in but they look like they could be restrictive. I am sure money is always a factor and it is for me too but you have more power just waiting to be unlocked. First mods I would look into would be a bigger cam. A very popular cam is something like a 226 intake duration. I personally like a little bigger in the low 230's. Next would be a ls6 intake. You can buy them used for around $300 and you should pic up 10-15 rwhp. Next would be look into a better set of headers and last a nice set of heads. Do those things and I bet you get over 400 rwhp with a tune of course.

springer_4

iTrader: (9)

Where did you get it Dynoed? Pure Tuning and did you have it tuned at all yet?

hardcore4sure

iTrader: (1)

Just throwing it out there your pictures show blue valve springs you say are LS6, but 1st gen LS6 valve springs are BLUE and rated for a .525 lift, second gen 2 LS6 valve springs are yellow and rated to .570. You may be experiencing some valve control / coil bind. Just a thought. Also, Even stock LS6 heads and LS6 intake would also complement the cam and should get you into the 350-360rwhp/TQ range. Or send the stock LS1 heads to Advanced Induction, there LS1 CNC program has shown some impressive gains.

Grr

iTrader: (2)

Dyno is likely not as high as some, ls1 intake is a big restriction, but in reality it's those headers man. They are probably costing you 20whp. Tri-y headers like that, done wrong cost way more power than they can gain. Add in how you made the, 180*, which they actually aren't at all, and that's probably worth another 10-20. For real if you put a decent long tube header on there I would not doubt you would pick up at least 25whp bare minimum.

DietCoke

iTrader: (18)

Yellow springs are gone. The modern springs are blue. There is no valve control issue evident in his dyno graph



Those headers look sketchy/questionable though. WAY too many bends. I think he's right where he's going to be through an IRS rear drivetrain, with that horrible header/exhaust design and an ls1 intake.

Tony Nichols

iTrader: (2)

Completely stock tune for a 1998 ls1 with emissions and vats removed, nothing else. I had it dynod at Accelerated with their Dynojet std.

I hadnt expected to pull super high numbers, considering it was a stock rebuild with an ls6 cam. Everything internally was pretty trashed or bent.

As far as the headers go, most bends are to clear the chassis components themselves, not exactly a realestate queen. I made a set of 17/8 long tubes, x pipe, and 2.5" and it seemed like it had a little more hp but not so much torque at all. It pushed the space contraints to their limits....#8 sat about 1/4" off the booster. The current headers are pretty close to being equal lenth and theyre 1.5" primary off the headers, merge into 2" when joining two cylinder 10" from the head, then step up to 2.5" when tied together from the other head. It uses mandrel bent tubing and is lighter than the old setup as well.

The car is IRS with semi-trailing arms, not multilink. On the dyno i had the factory 205/50/17s with the 4.10lsd. It was about 80 or so yesterday in the shop as well.

Tony Nichols

iTrader: (2)

What makes them incorrect for 180*?

tigertales

Its about what a LS1 GTO would put down. Its about right. The IRS is probably eating the power like they do on the GTO's.

thunderstruck507

iTrader: (18)

ls1 intake and no being tuned are costing a good bit

vettenuts

iTrader: (4)

Was it a hot day? Dyno curve is not SAE corrected, which if a hot day, might show more power.

NotoriouSS

header lay out is interesting
primarys look good to me
but..
the secondary pipes on the headers are way too small in dia.
bump the secondarys to 2.25-2.5" and power will dramadically go up!

thumbs up for trying something new

Tony Nichols

iTrader: (2)

I don't know much about dynos themselves, but as state before it was on a dynojet, 80 degrees or more, and the print out said STD. Brought the car in, they strapped it by the trailing arms, made 5 pulls, then kicked it out the door. No other readings or anything were taken, literally on the dyno, run run run, off the dyno. The only other issue is that the o2 sensors were unplugged because they shorted the circuit and blew the maf sensor fuse as well. They said it wouldn't cause much drop in the dyno if any at all, so I didn't worry about it.

As far as the headers go, they're 2 to 1, 2 to 1. There's not a lot of room to increase to 2.25" before they merge to a 2.5" collector and straight pipe back. The only "off the shelf" headers for this chassis and engine is 1900shipped by themselves, I made these in a week and a half on 250$.

redtan

iTrader: (5)

If you can make your own headers then why didn't you just make the regular 4:1 long tubes with the right size piping? Those look more like a rats nest then headers.

And the fact that the primaries merge so quickly after the heads they basically are fancy shorties with longer collectors. Not exactly power making pipes right there.

vettenuts

iTrader: (4)

I believe the SAE standard is 77 degrees, so if corrected the numbers would might go up some but you also need the humidity information as well. I would be PO'd if treated like that, perhaps a new dyno shop is in order here.

Gunslinger09

Did your machinist degree the cam? If he did the instal one tooth off thing may be what's costing you some power. I agree with the others about your headers they are probably costing you some power also a tune and Ls6 intake would get you some gains.

Whiskeyboy84

iTrader: (8)

Hey man dont get bummed! IT is most likely your tune holding you back but think of it this way an actual LS6 in all its glory stock tune no bolt ons generaly only puts mid to high 320's to the wheels and your talking 243 heads, Light weight valves, higher compression and lots of GM research time and money in the tune. Like it was said earlier be happy with what you got for what you paid and know you are about right. As far as the cam timing goes ask your builder if he degreed the cam and see if he can tell you if it is plus or minus whatever degrees. It is highly recommended to degree a cam because not all cam grinds are created equal even big name companies will tell you that cams that share the same part number and specs are not ground identical so degreeing your cam is essential to knowing your true timing. Also to Diddo on those headers all those different connections made with mig welder it looks like will cause all kinds of exhaust restrictions because you are narrowing the inside diameter of the pipe at each one of those junctions even though its no much that many times it adds up I would be willing to bet you would pick up just going to a corvette exhaust manifold and having an exhaust shop run you a mandrel bent down pipe to your existing exhaust.

speer13

Theres going to be a lot of opinions here etc. looking at everything you have done I'm going to say its your headers... your tune even with an LS6 cam should be good for 300-320 at the wheels. Header size and design is critical for any engine especially one that breathes like an LS1, you are using the tri-y design and its not even the correct layout... you want the cylinders that are Y'd into each other to be 180 degrees out from each other while firing.. most can't do that with cylinder layout... but to get close most designs mate 1&5 3&7 on one side where you have 1&7 and 3&5 so there could be a scavaging issue to begin with... next if you have reduced the size of the two primaries in the Y to the size of one of them you have massive restrictions and I'm surprised you made as much power as you did and made it to the RPM you did... I have watched N/A guys on the dyno for weeks working on different primary sizes and lengths and bends all to find 1-2 horsepower

Tony Nichols

iTrader: (2)

I had to put my DD in the garage to replace the rear diff, so i HAD to drive the ls car, thats the only reason it even hit the dyno when it did. I have my old 1 3/4 headers sitting in the garage but no midpipe to install them to, so i cant hook up the o2 sensors. I could reinstall them and, make another midpipe, and see if its honestly the headers or a combination of the headers and the tune. I just dont feel like shoving out another 75$ just because.

The cam was installed dot to dot.

Talked to the dyno shop, after talking to some more ls guys, they dynod in 3rd gear, which is wrong?!?! Im still just shooting in the dark at the moment. I have a guy, about an hour away, who does ls tuning that is willing to take a look and tune it for me as well. As long as its healthy, reliable, and does what it should, ill look to the brighter side. wasnt going to huge numbers after all, otherwise i wouldnt have bought a stock cam.

S8ER95Z

iTrader: (3)

My car was done in 3rd gear... It didn't seem to hurt the numbers at all. (324rwhp/342rwtrq SAE with just FRA mod) I will say on stock tune the ls6 cam was a little weak... I have yet to Dyno it but for comparison...


Bone stock - 13.1 @ 108.59 on a 2.19 60ft (DA -127)
Ls6 cam, FRA/LID - 12.88 @ 110.07 on a 2.04 60ft (DA -300)

Numbers above are with mods listed and NOTHING else done. Car was 3440lbs, full tank of gas and spare/jack still in it both times.

Shifting at 6k and ran pig rich.... I would guess your tune and the ls1 intake are hurting you the most. Any updates?