What rpm does the ls9 cam like to shift at with the 6.0???

[desertg8]

It seems like it is still building power at the stock 6000 rpm shift level. I know the zr1 vette hits top power at 6500. So obviously I am not making near the power of a zr 1. Has any one determined the best rpm to shift at with this cam? Brian, what say you?

I am thinking it is around 6300 with basic bolt ons like headers, ported intake, manifold, cai, etc.

Also it seems like the wider lsa likes less ignition timing. Is that correct or am I imagining that?

[G8-4-Speed]

I know the 6.2, LS9 cam, KB 2.8, headers/exhaust will run to 7000 easy. Will pull to 7300 with good internals. The wide LSA makes it real top-end type cam. Just tuned one and shifting at 7000 felt like I was cheating it.

[G8-4-Speed]

Stock timing seemed fine except at the very top of the chart. 40-45 ok but that cam would push the timing to 50 or so and it was too much. No spark knock but the engine would run a little ruff on decels and very light throttle from the timing being too high.

[hulkss]

If you mean shifting for best 1/4 mile time, shift at the highest rpm possible without damage.

If you had very high rpm capability and closely spaced gears, like a 7 speed motorcycle, you would rev out the engine until you match the axle torque in the next gear - then shift. In the G8 that's not possible, so just rev as high as you can safely.

http://forum.grrrr8.net/attachment.php?attachmentid=10850&d=1301762890

[desertg8]

I am a wimp. Procharged, Alex, from this board is going to set the shift points for me tomorrow night at 6400/6400/6300. Dod has been removed. I have the comp chromemoly pushrods, and the gmpp springs. The springs when I research them are the original z06 springs. Good for a lift of 570.

I went to Firebird yesterday. With the superchips tuner in 90 degree heat at a da of 4000 plus I ran a 12.40 at 109.5. My best time there with the stock cam was 12.3 at 108.1. But it was 48 degrees out with a da of 1000 feet. I was able to get plus 100 rpms on the chips tuner when I did the run. When I set her to plus 200 she hit the rev limiter even though the rev limiter is set to 6500 on the chips tuner. Has to do with mph.

I lost a full tenth for the 60 foot times. But the top end and times were way better than the 12.3 considering das and timing was being pulled due to the high record heat.

Part of the 60 foot getting slower was also from the big meats that I had on. too much on the 9.5 inch rims. 315 35 17s. Did not need them.

A mixed good bag considering the very high heat, no tune, and too large of tires.

[bullett]

very nice! tomorrow my tuner will play with that and timing and afr as well with my new gear change and FAST intake

[desertg8]

just spoke with a professional tuner in phoenix. i am going to see him the 23rd. i am getting misfires at idle according to hp tuners. he told me that is the tune. it needs one badly. also he said this cam loves to rev high and create power. once on the dyno he will lock in shift points. but he gave a preliminary shift point of 6700.

tomorrow night i am driving up to phoenix one more time. it is actually going to be in the 60s with das in th 1800 foot range!

one last time for the chips tuner!

[Devilish34]

It's not as simple as set an RPM to where you want to shift... Mine shifts at 6550-6600 but my command RPM is lower than 6000.... MPH plays a big part into the actual shift point

[gr8lover]

Isnt it true on these cars that MPH controls shift points.... I have heard that the best way to do it is to set RPM's low and then concentrate on your MPH's...... is it true that it has to first see you are above a certain RPM and then it will shift at commanded MPH........ I have seen this in many places... is this not true????

[desertg8]

oh yeah. found that out when Alex tried to help me. we were hitting the rev limiter. we set her at 6400. bang, bang. hit the rev limiter and knock retard.

but what is the common sense of this. if you set rpms at 500 less; but raise mph is that how it is done?

at any rate Nic D. in Phoenix is a pro. He sais he will get the random misfire gone at idle and depending on the dyno runs set her at around 6700 or so with the ls9 cam with no hitting the rev limiter.

[Devilish34]

Isnt it true on these cars that MPH controls shift points.... I have heard that the best way to do it is to set RPM's low and then concentrate on your MPH's...... is it true that it has to first see you are above a certain RPM and then it will shift at commanded MPH........ I have seen this in many places... is this not true????

Yes....

[desertg8]

well if it does not rain tomorrow night even with the superchips tune I expect a new personal best. at a da of 2000 instead of 4000 with the smaller drag radials i expect 12.1. corrected to about an 11.7 at a da of none. but talk is cheap. we will see tomorrow night with no tune except an 87 superchips tune. can't wait till the 23rd. finally, a tune!!!

[desertg8]

did not run as good as expected. 2200 da

12.31 at 110.66 matched my best time with a stock cam. but mph went up by over 2 for a new best for me. that is with a 6000 rpm shift.

I had to shift at stock rpms. hitting rev limiter.

can not wait till the 22nd.

get rid of the random idle misfires and dyno tune her to a shift point at around 6700.

this cam definitely is a top end cam. you do lose a little torque in the first sixty feet if naturally aspirated. but once tuned you pick up on the big end alot. i have no tune and am seeing the top end go up.