3.73s vs. 4.10s
- Thread starter 1sik32v
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driller
Dedicated LVC Member
That's a good. Point... I have to question if the stock camsreally make any additional power beyond 6k. I'd bet a set of cobra cams would do the job.... regardless I'm getting an xcal next week so I will hopehopefully get a chance to play with some tunes
Right on the Mark
Dedicated LVC Member
Just because it shifts at those rpm's doesn't mean it's any faster.
I have not been to track yet to see the difference in ET's going from 6600 to 7000. But all times before to track car went fastest shifting at 6600. I worked my way up from 6000 just to check what was fastest. Hoping 7000 does not slow car down because I like the leave it in D and smash gas deal.
Right on the Mark
Dedicated LVC Member
Ask everyone that has a chip burned for them from the big name guys what they raised the shift point to. It will be in range I stated. All the early chips where set at 7000 then I think they brought them down a tad. Cobra cams one is the same and one cam has couple more degrees duration I heard. I will check on that. But someone will fill us in by time i'm done eating. LOL
driller
Dedicated LVC Member
The point is raising the shift points from stock to xxxx will make the car run faster... than stock. So any Joe who sells a chip and raises the shift points above stock makes a happy customer.
The question is... what is the best shift point for the most performance from any particular car? This can only be achieved as you stated... trial and error. In your particular example, 7000 may be better than 6600, but 6800 may be better than 7000.
The 2-3 shift points will not be the same rpms as the 1-2 shift point because of acceleration differences.
Hey guys I got my gears done on Friday. Went with 4.10 gears but haven't had the speedo gear replaced. Well today I finally got to get on it and the car acts like the govenor kicks in at 100mph on the speedo and 91 on my gps. Any ideas? My only thought is that the speedo gear is playing tricks on the ecu.
Ok so I had my gears installed went with 4.10 and well I am having issues. I finally got thru the break in and decided have fun with em. How ever the governor kicks in at 100 mph according to my speedo. Now I didn't replace the speedo gear for the trans is this the issue?
look up one post.
no worry did you see my post about the driveshaft rotation?
If I had to do it over I would bring it to a shop and have it dynotuned. The only experience I have with a chip is with sct. For the time being think of the limiter as a way of saving gas money. How do you like the gears?
Right on the Mark
Dedicated LVC Member
All 8.8 gears interchange. You could get gears from an Explorer,stang and so on and they would work.
KStromberg
Dedicated LVC Member
I'll put in my two cents.
4.10s all the way. The driveability is not as bad as some people make it out to be. Even on the highway you can get decent mileage. I'm running 4.30s and I drive on the highway with them even. Only a 200 rpm difference from the 4.10s, so if you want my honest opinion. 4.30 gears are the killer gear for a Mark VIII.
Here's my other cent:
Some are asking about shift points? Revving the engine out to 6800+ rpms with our stock cams/internals is absurd. And yes, the powerband pretty much nosedives after 6000 rpms and sometimes before which is another reason why it is senseless. My dyno sheet reflected peak power at about 6K rpms with full exhaust, stock intake and bolt-ons last year on the dyno. I have been through this lapse of judgment with my tuner having him raise my shift points and it produced nothing. Shift points need to be set at the top of the powerband and at an rpm which is going to put you at the best spot in the next gear. If you are shifting at 7000 rpms and your peak power is at 6000 rpms, you should have shifted 1000 rpms ago and you just wasted time and energy just to wind the car out more.
4.10s all the way. The driveability is not as bad as some people make it out to be. Even on the highway you can get decent mileage. I'm running 4.30s and I drive on the highway with them even. Only a 200 rpm difference from the 4.10s, so if you want my honest opinion. 4.30 gears are the killer gear for a Mark VIII.
Here's my other cent:
Some are asking about shift points? Revving the engine out to 6800+ rpms with our stock cams/internals is absurd. And yes, the powerband pretty much nosedives after 6000 rpms and sometimes before which is another reason why it is senseless. My dyno sheet reflected peak power at about 6K rpms with full exhaust, stock intake and bolt-ons last year on the dyno. I have been through this lapse of judgment with my tuner having him raise my shift points and it produced nothing. Shift points need to be set at the top of the powerband and at an rpm which is going to put you at the best spot in the next gear. If you are shifting at 7000 rpms and your peak power is at 6000 rpms, you should have shifted 1000 rpms ago and you just wasted time and energy just to wind the car out more.
Right on the Mark
Dedicated LVC Member
People the RPM figures I'm giving are off the stock tach. These #'s can be off as much as 500 rpm at 6500. I don't have datalogger in car to know exactly where its shifting at. Again i'm going off stock tach here. From stock tach readings the car WENT fastest when it was saying it was at 6600 rpm. I will be getting tach input so I can log this in future.
philly0420
Dedicated LVC Member
My car shifts somewhere in the red according to the tach. IIRC its around 6300-6500rpms
KStromberg
Dedicated LVC Member
200 rpms can be a HUGE difference. SO which is it 6300 or 6500?
And Right on the Mark, sounds accurate to me. I've heard of the tach lag and such myself. I assume that I'm shifting at 6500 rpm, not because the tach says so but rather that is where the computer is being told to shift via the tune.
Anyhow, every car is different and it really all depends I guess. Maybe the choice of stall range and gearing has an effect on this too? That was just my experience, and the double-clutching effect into second gear started in the tune once the chip came back with raised shift points. I've had buddies with this similar experience. It's probably the combination of that and mail order tunes are just fail. Not knocking anyone in the business but my tune has been fail from the start and sent back and forth many-o-times. It's a "poke and hope" method that I don't care to revisit. A handheld tuner with the ability to change the lock-up and shift points is the way to go or a local tuner who can put his hands on the car and drive it and make changes if need be.