with the vortech you will shift to 4th anyway, but you got to see what mph other guys are getting with a similar setup and you want to run 4th to the end of your rpm range where you are making power. as far as I know, 373s are a good choice for a centri, the stock gears will take a bit longer to get into boost so keep that in mind for the track.

 

410s I think would be better for centri. But I got 373 because I planned on going ts but ended up centri and I get up in boost pretty quick still. If you already have then they're good, keep em. No need on swapping for just a little bit of change.


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---------- Post added at 12:44 PM ---------- Previous post was at 12:43 PM ----------

Im loud in every gear except 5th, it sounds like stock and I need that for the interstate lol its so loud.


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Take the money, put it in the bank and save for the supercharger. If you want one you can't be piddling your money away on bolt-ons. After you get the supercharger then decide what gear you need.

 

Well I want to get everything I can (supporting mods) cuz once I get a supercharger Il be putting all the money in that, and honeslty the 3.73s is all thats missing to get all bolt ons, anyone running 3.27s with vortech ?

 

honestly with supercharger in near future, i would forget about rear gears, if your original ones are good, keep em. I think a lot people miss out on the higher highway speeds on the factory gears as well as the added vibration from new gears at higher speed can be less than desirable. not to mention for the new gears to be even effective you would want to upgrade your suspension and tires if you havent already

 

well people like you make me sceptical about changing gears.. my suspension is pretty much done, really all I have left before the vortech is 315s tires in the back and gears

 

Or u could forget gears, keep stock and go kenne bell:good: instant full boost.



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and sacrifice the bullitt intake and avvufab throttle body? I dont think so, its rdy to be boosted,

 

I went vortech over kb because my tb/plenum wouldn't fit and I sort of wish I woulda just changed it out. Twin screws are so badass. I love my centri still though. It's just some food for thought


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honestly I think without cams and valvesprings, the 4.10s are too much. 4.30s on stock diam tires im running out of gear at the strip.. no more left in it. 4.10 would be better for me.. for boost at all no matter what the type, I would go 3.90 or lower. these things just don't turn enough rpm safely IMO.

 

I've got 3.73's and a tr-3650. 5th gear 62mph @ 2000 rpms its quiet. Go over that 2k mark and it starts making noise. I was still able to manage 23mpg supercharged on a road trip to DC from NY at a steady 70mph.

Now as far as the track is concerned, I run through the traps on a 26" tire at 128mph in 4th gear. And redline is 132mph. So that's damn near perfect gearing for me.

I'd go with 4.10s if your making anywhere near 400whp though.

 

definitely good info for the guy. reps. does the OP have the tr 3650? I don't remember what an 01 has. I would take into consideration that he like the stock gears as it is now, the addition of gears and boost will make a wild difference. but he seems to want to get rid of drone, which would only need a mild gear change, and a good 1/4 mile setup. I wouldn't push him to go too far with his gear swap given his desires.

 

well honestly theirs to much goods with the 3.73s , Im gonna order the kit from americanmuscle, with my plans on a vortech and stage 2 cams later on gears seem a must, hopefully it will take the drone away too

---------- Post added at 07:33 PM ---------- Previous post was at 07:22 PM ----------

but is there anyone else that has/had 3.27s with a vortech >?

 

I am rocking full bolt ons, full exhaust, and cams. I have run 3.27 stockers, 3.73's. and 4.10's. So far my favorite have been 3.73's. Sure I love my current 4.10's but I feel like I shift gears every 2 seconds, and I almost think they hurt me in the 1/4 mile. They definitely do in the 60 ft for sure. I kind of wish I put another set of 3.73's in when i toasted the old ones.

I have an 01 with a T-3650 trans. btw

at 60 mph in 5th with 4.10's I am churning around 2,000 rpm. 80 mph I am screaming at 3,000 rpm. with normal driving I am almost shifting into 3rd by the time I leave the intersection from a red light. at 40-45 mph in 5th you'll be at like 1500 rpm. It is a bit ridiculous to be honest. I usually net about 17-18 mpg whether it be highway or town driving.

I'm sure 4.10's would be wonderful at the track with a 26-28" slick with a blower but I think 3.73's are a better way to go. You will stay in boost longer than 4.10's and get into it quicker than stock without killing your mileage.

 

you will be happy with the 3.73s I think. I don't like my 4.30s and im just intake exhaust and weight reduction, way too much shifting and im near stock with bolt ons and a k member.. just intake and exhaust only on the motor. terrible on gas, loud on the highway turning 3200 at 70... you got it figured alright

 

damn that sound rough, what do you run in the quarter with that setup ?

 

i think i did 3.73s before the procharger was put on, so i can't give comparison with 3.27s. but i'm def glad i went with 3.73s, at the time. i had a t45, not sure what your ratios are. 3.55 probably woulda been a little better, but i already had the 3.73s and don't track my car. you should be happy with the 3.73s until you get more power or swap transmissions.

***actually, i can compare. i have still have the 3.73s, but put in the tr6060 little while ago, so my final ratio is almost identical to t45 with 3.27s. i hate it. tomorrow i'm installing the 4.10s which will put the final ratio just short of the t45 with 3.73 combo.

 

damn nice, I wish I hate a transmission with like a 2:00 ratio first gear.. I think the tr3650 has 3.37 as stock first gear, tht why I always take of in 2nd and the 3.73s would help tht even more so thats another advantage.

---------- Post added at 12:31 AM ---------- Previous post was at 12:29 AM ----------

I run stock gears with the juice and it rips to 120+ like its nothing.. I'd keep the stockers if your going supercharged but that's just me. I think gears are great for N/A cars. With the TQ pick up from the charger you wont need them

Ye but the thing with vortecs, everthing if up top, boost build and I belive its barely there down low, Is it true? How much boost do you have at 2k rpm?

 

I run stock gears with the juice and it rips to 120+ like its nothing.. I'd keep the stockers if your going supercharged but that's just me. I think gears are great for N/A cars. With the TQ pick up from the charger you wont need them

 

I run nitrous so the power is crazy insane everywhere for me I cant even hook in 2nd gear with my stock 3.27s spraying, Forget taking off from a stop for me. I mean your gonna hit boost so fast once you launch i'd think with running anything other then stock gears would just cause more wheel spin unless you really dump some money into tires and a great suspension setup. I used to have 4.10s I wasn't impressed, I'm that rare bird that made a rant about them on here

 

bof ive been doing it on my 6 and now this and never have problems, doesnt bog or anything, around town if im lazy I go 2 and 4, or first to third.It just feels akward andshifting from 1 to 2 seem to los a lot of momentum, when I floor it I obviously start in 1st but when Im just cruising I get lazy, i sometime shift with no clutch and use the revs lool

 

I've seen a lot of 4.10 drivers recommend starting in second. CliffyK actually said that in one thread. First is pretty short with 4.10 gears.

There is actually boost at idle. It isn't much but I can hold my hand over the BOV and feel the excess pressure being pumped to atmosphere. I do not have any measurable boost below 2500 rpm and it really doesn't amount to much but at 2500 rpm it was 1.8 psi and that created about 42 ft.lbs. of torque more than stock on the dyno. Maybe at idle its 1 psi and 10 ft.lbs. of torque, I don't know.

With 3.73s and a ProCharger my car rips from 3500+rpm. Hell, after 3500 rpm I have to keep close attention or else I'm bouncing off the rev limiter.

 

+1, had this discussing before and a lot of people take of in second with no problem, mostly ppl with gears but seems to work fine for me.


And I hope it get a lil more low end with the vortech since I drive around town no more then 2000-2500 but still wht I want, gonna sound normal but once I get to 3500 it leaves anything.

 

my setup now is similar to yours, and for me 1st is way too tall. might be good for launching, but don't like for street. can't imagine starting in 2nd. our styles are quite different it seems. hope whatever ya get is what u wanted.

 

keep factory gears and run the juice instead alot cheaper and it sounds like you can manage it more on your terms which is what you want

 

+1 that's what I'm doing. Problem is a lot of people fear the spray and prefer boost and boost appears to be the direction OP is leaning, even with that I'd run the factory gears for boost 3.55s are perfect for boost

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wet juice + methanol injecting has got to be the safest thing for these car, almost no risk of detonation, + its nice to not have your vehicle under boost all the time. just my 2 cents

 

4:10 with a 5speed 1st gear is so short your shifting right away. I had 4:10 with my 5speed for a bit before going with the t56. My t56 has a 2.66 1st gear and it was alot better with the 4.10 (wish i had gone 4.30 now) I would go with a 3.55 3.73 gear on the 3650 especially if you DD it alot. Oh, and you will need some DRs like the MT street drag radials to get any traction.

 

man, that's low. just get new gears. right now you have what would be 3.22's in 5 speed. 4.56's would put you at a 3.6 equivalent, that's a pretty nice spot.

---------- Post added at 08:04 PM ---------- Previous post was at 08:02 PM ----------

keep factory gears and run the juice instead alot cheaper and it sounds like you can manage it more on your terms which is what you want

for drag that's fine. but that's no fun on the street. boost is always available. no arm, open, purge, fill, crap. fun factor with boost is no comparison with spray, for street driving.

---------- Post added at 08:06 PM ---------- Previous post was at 08:04 PM ----------

wet juice + methanol injecting has got to be the safest thing for these car, almost no risk of detonation, + its nice to not have your vehicle under boost all the time. just my 2 cents

it's only boosting when you make it, not all the time.

---------- Post added at 08:08 PM ---------- Previous post was at 08:06 PM ----------

+1 that's what I'm doing. Problem is a lot of people fear the spray and prefer boost and boost appears to be the direction OP is leaning, even with that I'd run the factory gears for boost 3.55s are perfect for boost

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3.55s are very nice, but OP has an 01, which comes with a 3.27 stock. unless bullitts are different, i'm not familiar with the differences.

 

I reference CliffyK's calculator a lot. It matches my car exactly. With T-45/3.73s at 4000 rpm on the highway I'm running 40 mph in second and 80 mph in fourth. It's handy to know the rpm that you will have for your speed when downshifting. I think 3.73s are the perfect gear for a centrifugal supercharger especially on the street. First isn't too short and the highway rpm isn't too high with the T-45 and early T-3650 transmissions.

The idea that a centri doesn't make good boost until higher rpm is really a mute point. You don't race at lower rpm. At the track with a heated set of DRs you should be able to launch at 3000-3500 without spinning too much. After that the motor never gets below 3500. I started stretching first out a little farther to 6200 but if all shifts are at 6000 rpm then from 1st-2nd rpm drop to 3550, from 2nd-3rd it drops back to 3960, and from 3rd-4th rpm drops back to 4545 rpm. At 111.4 mph my car crosses the finish line around 5600 rpm.

My torque curve is relative flat (greater than 350 ft.lbs) from 4000-5500 rpm with peak around 4500. Peak horsepower is around 5900 rpm (stock cams). If I were building a track car I suppose 3.90s might be a better gear but I only occasionally take my daily driver to the track. In my opinion 4.10s are too much gear. At 6300 rpm torque and horsepower are starting to drop off pretty fast.

I have looked at the torque curves between centri and twin-screw blowers. The low end torque advantage of the twin-screw is pretty much gone around 4000 rpm and the only time a motor drops below that is the first second shift. At the higher rpm the centri has an advantage. The one thing that I've noticed about the data that the twin-screw drivers post is that they almost all run slicks or ET Streets to get enough traction. A centri with those tires could launch above 4000 rpm. That is why centris and twin-screws with similar boost run similar times.

 

^^^ Bullitts are indeed 3.27.

I drive my green one daily with 4.10's. When I drive the stock blue one it's such a dog.


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