i tried 3rd and 4th and noticed no differences, my runs came on a dynapack dyno which uses rpm calibration and automatically loads it to 1:1, you could dyno in 1st gear if you wanted to and it would be no different

 

Every dyno is different. If the dyno is calibrated properly to your car, the gains should be minimal in 4th but if they are off, I have see 10WHP gains.

 

dynos cant be off, its a calculation

 

The dyno is calibrated with a chart to determine parasitic loss of the car. This chart rises exponentially so it may only at 10HP at 60mph and add 50HP at 120. I have seen correction charts over 100HP at the top end.

So if the dyno is calibrated for a loss higher than what the Cobalt has at higher speeds, the chart would read higher than it is supposed to.

Now on the 3rd to 4th, technically the 4th gear pull should read higher because of the 1:1 gear ratio having less loss than the 3rd gear does. This is normally only a few HP though

 

swapped throttle bodies and made different power than before.... ill let him say weather it was good or bad, free bump

 

I had a 10whp difference between 3rd and 4th on the m62 and about a 2whp difference on the tvs on the same dyno.

 

4th is not 1:1 in the lsj/lnf cars.

 

Good call, the .89 is closer to 1:1 than 3rd gears 1.18 though. May make for slightly better efficiency.

 

.11 vs .17 doesn't make a whole lot of sense to put an extra load on a car and increase the iat's for more accuracy in my opinion. thats just me though. i personally prefer third myself. less wear on the dyno brakes. trying to slow the mass down from 140+ versus 120+ {depending on rev limiter of course}

we could go back and forth all day on this, but you get the general idea

 

New # with the stock tb where 290hp 240tq

 

That sounds alittle better !! So the ls4 tb was causing that much of a hp and tq loss for you ??

 

There is still a lot more you can get out of that though . Drop the pulley lower, add more timing, and beat the **** outta it lol.

 

ya and i really didnt like drivin with it.

timming 21.
wat i got for mods im happy with it for now.

 

Breaking the tires loose in 2nd gear... *giddy*

 

that was only a 10hp difference. How different is the powercurve now? If you lost a bunch of power down low, then I don't think putting the stock tb back on is worth it. losing 10 peak hp is worth it for 15hp through the powerband.

Can you post up both dyno sheets of stock tb vs ls4 tb?

 

yes please i would like to see them to .

 

i dont have the ls4 dyno sheet. but when i threw the stock tb on and didnt change the tune the hp an tq where the same.

 

mine made 290 whp also and 247 wtq with the ls4,its a touchy ****** ill tell you that. im droping down to the 75 mm pulley so i can have more tq and hp. my car only hits 20 psi at 7100i think the 75 mm pulley will let me have more boost down low and hit 20 psi at 6600, that way i dont have to wrap the moter that high to get the boost im looking for. I think it would be eaiser on the moter that way,

 

his car was strong the ls4 tb dyno was wavey and odd looking just swapping tb's nade the power smooth out and run hard

 

i was hittin 20psi around 6500 and brang it to 7200

 

i think way my car is boosting 20 at higher rpm is be cause of the full 3" catless exhaust.

 

I'm not sure if this is feasible but.....you should put the lowest pulley on the blower that you can run safely without damaging the blower itself and then limit your boost pressure with hp tuners. You'll get more torque and the boost will come a little faster. I'm pretty sure you can do this through HPT.

 

that sounds like a good idea,ill talk to my tuner and see if thats doable.That does make a lot of sense tho

 

there are a few problems with your logic. the bypass is slow. your car in first and even second will boost 100 percent before it opens. so your looking at 30 or so psi way early. its not good on stock pistons, and second is your blower will be spinning at that speed all the time. so its life span will be cut way down

 

So your telling me if I set the boost reduction to only 50% in 2nd gear a person who normally boost 20psi would not boost 10psi? I think not. I have tried, tested and proven that boost reduction in hptuners DOES in fact work. Granted the TVS applications might be different as I have never "personally" tuned a TVS before, however boost is boost and limitations from ecu's are limitations from ecu's lol.