Sorry if this has already been brought up but isn't it weird how the two Dyno charts provided by GM show the stock LSJ start losing power after 5500ish RPM? Almost all stock LSJ dyno's I've seen show them building power up to 6500.

Could it be that these charts were modified to match GM's underrating of the engine?

 

sir, your right.

 

agreed ^^^^^

 

Where did you see the dyno sheet for them at?

 

Ok I went looking and here are two examples I have found.

First, from the Stage 1/2 installation posters, GM's dyno chart.



Notice how the HP starts to dip after slightly above 5500 RPM.

Now, from Doc's stock '06 SS/SC



Notice how the HP builds all the way to redline.

I'm cautiously excited about this. If GM is going to stick by their story that a stock LSJ is only putting out 205 HP and even show us graphs as evidence, then GM's rating of 245 HP for stage 2 might be more like 280 +

I'm wondering if Doc had the boost bypass mod done, could that be the difference between his dyno and GMs?

 

I haven't done the boost bypass

 

Sweet. So that shows that GM's dyno of a bone stock LSJ differs from a 'real world' dyno of a bone stock LSJ.

Fingers are crossed that stage 2 is equally or more underrated.

 

My fingers are crossed too. I have a feeling they will be too. 31 hp for the ecu, 5 hp for the pulley? 5 HP FOR A 3" PULLEY!?? Right there it misleads you.....

 

There are so many factor with dynos that it is hard to say. Also you are comparing a engine dyno to chasey dyno. Big difference in accuracy. chasey dyno's being the least accurate. It would be nice to see someone take out there LSJ and put it on a engine dyno and see it it is really under rated. I still think that it is. Also the stage kits will more then likely follow with the same under rating, especially if they used the same engine dyno and same scenario to test them.

 

I know an engine dyno and a chasey dyno will differ, I just wouldn't think that the slope of the graph would change so drastically.

I'm wondering... could GM have used 87 octane for it's dynos? Maybe it's pulling timing near the top end, that would explain the drop off.

 

i dont see how your getting that the first dyno was showing them underratting, maybe the graphing wasnt right but the peak numbers matched what alot of us have pulled. the peak on the "production" part of that first dyno is around 223-226. and it doesnt dip, its more of a flattening out, but right before the stock redline, that is a dip...

GM underrated this motor from the get go because their dynoing of the stock motor stopped way before redline which is where we all know that we make the most power. on their stock dyno they had it going to 205 then flattening out for the rest of the rpms like they just didnt bother to go any higher than that.

i think the stage kit will be right on the money as far as the numbers they make. i may be wrong though, we'll see...

 

That shows the stage 1 reving to 7000 rpm. Do the GM Stage kits bump up fuel cut?

 

That's what we are hoping

 

i just got tired of waiting. but i think it comes down to Rev it Up and GM. i bought Rev It Up and even if GM produces more HP. I have more long term potential with Rev It Up. But for short term. the warranty is the way to go. I think GM will dissapoint everyone like they have done so far.

 

When does your fuel cut out?

 

i wont be dissapointed, the car is pertty quick to boot, i have a few lil mods here and there that help, with stage 2 and a possible clutch ill have a pretty fast ride, and its warrentied, not bashing the other kits out there, they have mad potential and maybe put out more horse, but with more horse comes mo problems, i dont need my ride that fast cuz someone will always be faster,just my 2 cents...peace .

 

I plan on doing a mix between the stage 2 and the intense kit. Use the reflash from gm stage 2 to higher the fuel triming, then use a maft to fine tune it with a 2.8 pully. I have some links at gm dealers and what not, and im hoping i can just get the reflash, but if i have to buy the entire stage 2 kit, i will just sell the injectors, belt, and pulley. I'm sure someone would love them.

 

I have fuel cut right at 6500 RPM....which is where it's supposta be. Although a 2.0L has a short enough stroke that we could likely rev to 7500RPM safely as long as the valve springs hold up.

 

Thats weird, I don't have fuel shut-off at 6500rpm, I have a rev limiter that I have bounced off of a few times though!

 

fuel shut-off = rev limiter