SIZEMOREMK
02-21-2014, 11:54 AM
I know the 4.10s discussion has been beaten to death here, but I would like to here from someone with a similar setup (centri).
Car is an 04 MM, Paxton 1200, cobra MMR 600 shortblock @9.5:1, headers with basically stock exhasut, stock 4r75w/converter, musclemerc LCAs.... Will be daily driven. I have a pretty simpe/easy (traffic aint bad) 18-20 mile commute, and run 70-85 for a good portion of it (even in rush hour).
I've got a Thunderbird SC (3.8 v6) with an aftermarket version of the Eaton M90 and other bolt-ons; that setup with the stock 3.27s had plenty of low-end grunt. I had a set of 3.73s that never actually made it into the car, due to my fear of high revs and mileage. But was satisfied with the low end.
But now with the MM and the centri, and feel like I'm missing out in the bottom end. This thing doesn't hardly even spin the tires from a dead stop, granted they are brand new tires and seem like the softest/grippiest tires I've ever owned...
Another factor is likely the lack of boost due to larger pulley. I had the car dyno-tuned at Reinhart's last Sunday and he said I needed a smaller pulley.
Car maxed just over at 8# boost in the 6K neighborhood on the dyno.
If I stab the throttle from normal speeds, the guage gets to 5, maybe 6 in the middle of the RPM range.
So I do need to measure the exact SC pulley and probably step down a size or two. Reinhart said he gave me a conservative enough tune that I could go down a size or two and be OK. I do have a wideband setup that will go on it prior to pulley change, so I'll be able to datalog and verify eveythig is safe after any mods.
So looking for inputs please:
3.55s with Stock coverter
3.55s with 3500 stall
4.10s with stock covnerter
4.10s with 3500 stall
Also which order would you recommend I change theese in? 4.10s first or converter first?
The tranny/TC is stock, so I'm also considering pulling it to have the converter built/replaced (PTC is local to me and I've had good luck with their converters in the past), if I pull the tranny, it will be built to "Js" bulletproff 4r70w specs.
No signs of tranny issues yet, but I'm not pulling it without rebuilding it.
So wondering if I need both 4.10s and 3500 TC, which I should do first.
Thanks guys!
Car is an 04 MM, Paxton 1200, cobra MMR 600 shortblock @9.5:1, headers with basically stock exhasut, stock 4r75w/converter, musclemerc LCAs.... Will be daily driven. I have a pretty simpe/easy (traffic aint bad) 18-20 mile commute, and run 70-85 for a good portion of it (even in rush hour).
I've got a Thunderbird SC (3.8 v6) with an aftermarket version of the Eaton M90 and other bolt-ons; that setup with the stock 3.27s had plenty of low-end grunt. I had a set of 3.73s that never actually made it into the car, due to my fear of high revs and mileage. But was satisfied with the low end.
But now with the MM and the centri, and feel like I'm missing out in the bottom end. This thing doesn't hardly even spin the tires from a dead stop, granted they are brand new tires and seem like the softest/grippiest tires I've ever owned...
Another factor is likely the lack of boost due to larger pulley. I had the car dyno-tuned at Reinhart's last Sunday and he said I needed a smaller pulley.
Car maxed just over at 8# boost in the 6K neighborhood on the dyno.
If I stab the throttle from normal speeds, the guage gets to 5, maybe 6 in the middle of the RPM range.
So I do need to measure the exact SC pulley and probably step down a size or two. Reinhart said he gave me a conservative enough tune that I could go down a size or two and be OK. I do have a wideband setup that will go on it prior to pulley change, so I'll be able to datalog and verify eveythig is safe after any mods.
So looking for inputs please:
3.55s with Stock coverter
3.55s with 3500 stall
4.10s with stock covnerter
4.10s with 3500 stall
Also which order would you recommend I change theese in? 4.10s first or converter first?
The tranny/TC is stock, so I'm also considering pulling it to have the converter built/replaced (PTC is local to me and I've had good luck with their converters in the past), if I pull the tranny, it will be built to "Js" bulletproff 4r70w specs.
No signs of tranny issues yet, but I'm not pulling it without rebuilding it.
So wondering if I need both 4.10s and 3500 TC, which I should do first.
Thanks guys!