Shift Point With Stock Cam????

[14chp2c]

I was wondering on what I should be shifting at with a stock cam for a Ford 306? I am shifting at 5800 with a box  Hogan upper intake, GT40 lower, TFS Twited Wedge heads, 306, stock cam retarded 4 degrees, 1.7 rockers, MP-T70 with 14lbs of boost, the best I have ran is a 10.000 @ 138.9 MPH. Should I try lower than 5800?

[82 rustang]

I just kinda shift where it feels like the torque starts to fall off?

[underpsi68]

Heres a stupid question for you:  Are you using a factory tach?

[14chp2c]

I am using all Autometer gauges, all Factory Gauges have been deleted.

[nealysa]

Those heads are really good and will let it rev higher than normal, but the gt40 is limiting on the induction.  With a better lower manifold even more rpm is ok.  The problem then becomes the SADI cam you have (stock).  It will flex and vibrate quite a bit causing valve train instability.  Heavier springs would help some.  Good luck.

Sean

[14chp2c]

I already upgraded the valve springs in the heads and had heavy port work done to the lower intake

[nealysa]

Than your most likely weak point to raising the rpm is the cam itself.

[14chp2c]

Well it seems like I can shift higher, I just havent tried it, I just couldnt believe I could shift a stock cam higher than 5800 and make a difference, that is why I am asking to see if anybody has tested this, but I do have the cam retarded 4 degrees if that makes a difference.

[slo5o]

Have you dyno'd it to see where you make peak torque at? I also think that box upper is raising your torque peak up some allowing you to get away with shifting it higher. Post a timeslip up and what rpm are you running through the traps at?

[14chp2c]

I will have to ask my tuner for another dyno sheet, he only gave me one that shows me power curves at MPH not RPMs. I am crossing traps somewhere between 6000 and 6200 rpms.

[nealysa]

Have you dyno'd it to see where you make peak torque at? I also think that box upper is raising your torque peak up some allowing you to get away with shifting it higher. Post a timeslip up and what rpm are you running through the traps at?

The manifold and heads (induction) are allowing the cam to spin higher (usefully).  It's just that this OTS SADI cam won't have good stability  which means your valve train won't be stable either.

[Litemup86]

My setup made 506 hp and 530 tq to the tires with the stock cam.  Trick Flow twisted wedge out of the box, 1.7's, old Performer RPM intake, and Incon 800 TTI kit at 10 psi (twin GT-35's).  On my dyno sheet, torque curve starts falling off right after 5K and hp falls right under 5,500.  I shift right at 5,500 and use the low end torque. 

[14chp2c]

Litemup86, did you try a little higher or a little lower rpm shift points than 5500 and see any difference at the track, they always say turbo cars always act different on the track then on the dyno.

[slo5o]

The manifold and heads (induction) are allowing the cam to spin higher (usefully).  It's just that this OTS SADI cam won't have good stability  which means your valve train won't be stable either.

I agree about the cam but I think he would make more power under the curve with a better intake.

[14chp2c]

My intake is flowing more than my heads unported TFS heads, I had it ported and flowed to 300 CFM,  yes I am talking about my GT40 lower.

[14chp2c]

I just got off the phone with the tuner, he said peak HP was at 5300 and peak TQ was at 5100, he said that  HP at 5300 is the correct RPM peak but said peak TQ could be different due to converter slippage, he just said  just to do trial and error at the track.

[Turbo91GT]

Those heads are really good and will let it rev higher than normal, but the gt40 is limiting on the induction.  With a better lower manifold even more rpm is ok.

I just saw an 88mm coupe run in the 8's today at hrp with a gt-40 lower downs upper

[14chp2c]

Thats what I like to hear, old school stuff like the GT40 lower & Downs Upper running 8s.

[slo5o]

My intake is flowing more than my heads unported TFS heads, I had it ported and flowed to 300 CFM,  yes I am talking about my GT40 lower.

And I was refering to your runner length. peak flow numbers dont mean a whole lot.

[gotageta5oh]

I shifted at 5500 when my old LX was mostly Stock.