Gears vs FI - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

SS_Dave · 06-08-2025, 11:40 PM

So, I've read guys generally stay away from taller gears when going FI. Like 3.91's or 4.10's. I have 3.91's, btw. I'd like to understand more about the reasoning for it. Is it more about high RPM for extended periods like highway trips overheating your blower? 3.91's are only a couple hundred RPM higher. Or what are the issues? And for that matter are certain types more sensitive between roots, centrifugal or whatever. Turbo as sensitive as well? I've been considering at some point going either LSA or ProCharger.

larry_g · 06-09-2025, 07:01 AM

I'm not positive, but I'm going to guess it has to do with available traction. My car has 3.91 stock and I can tell you first and second gears are just about useless with street tires.

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CamaroCracka · 06-09-2025, 07:51 AM

I have 3.73s with a turbo and it smokes the tires in second on the street. Any more gearing would be useless. I run a 325/30/20 Sport Cup2 on the street. PD blower would be even worse for traction. You could run a drag tire on the street for more traction, but handling would be ruined.

If you drag race, it also has to do with where you are at the end of the quarter. You would not want to be trying to shift to fifth at the end of a run. My car is at the top of fourth at the end of the quarter.

Now if you are into drifting on the way to the grocery store, gear away.

*SSE 4 2SS* · 06-10-2025, 06:22 PM

I went the other way with gearing due to my choice of racing.... I went with 3.07 gears, and a slightly different ratio in the transmission, and yes I could smoke the tires in 1st-5th gear, almost at will... Which is why I ran a very good traction control system. ProEFI

Turn it off and do 200+ mph burnouts in 5th gear... It was interesting to say the least...

Traction is the biggest reason people avoid gears in the 4.XX or more range. For a few as was also mentioned it's the potential highway RPM range... However, the 6 speed transmission does help with that... This isn't the 70's or 80's with 4 speed transmissions...

As for overheating a forced induction system on the highway, you are typically making little to no boost as cruise throttle settings.... If you pulley down to spin the blower faster, you might minimally create some heat in it, but again, as cruise throttle positions there is often no boost being created, you're just spinning it a bit faster with "no" load...

06-08-2025, 11:40 PM	#1
SS_Dave Drives: 2011 Camaro 2SS/RS Join Date: Jul 2021 Location: McKinney, TX Posts: 501	Gears vs FI So, I've read guys generally stay away from taller gears when going FI. Like 3.91's or 4.10's. I have 3.91's, btw. I'd like to understand more about the reasoning for it. Is it more about high RPM for extended periods like highway trips overheating your blower? 3.91's are only a couple hundred RPM higher. Or what are the issues? And for that matter are certain types more sensitive between roots, centrifugal or whatever. Turbo as sensitive as well? I've been considering at some point going either LSA or ProCharger. Last edited by SS_Dave; 06-09-2025 at 12:07 AM.

06-09-2025, 07:01 AM	#2
larry_g Drives: 2014 1SS/1LE Join Date: Nov 2015 Location: Louisville, KY Posts: 875	I'm not positive, but I'm going to guess it has to do with available traction. My car has 3.91 stock and I can tell you first and second gears are just about useless with street tires. Sent from my Pixel 8 Pro using Tapatalk __________________ 830 WHP 700 WTQ, Whipple 2.9 @ 13lbs Boost, Flex Fuel Tune by Blevins Tuning, LSA SBE, 3.5 GripTec, ATI LS3 Damper, AFR 260cc Mongoose, ARP Studs, Yella Terra Ultralites, Johnson 2110R, BTR PDS Stage 3, Melling 10355, Improved Racing Baffle, ID1050X, DSX Triple Fuel Pump, RotoFab CAI, NW 103mm TB, Stainless Works 1-7/8" LTH to 3" Speed Eng w/ X-pipe to NPP, Powermaster 9509 XS, Detroit Speed Motor Mounts, MGW, Monster LT1-S, ZL1 Calipers, DBA Rotors & Pads, Bilstein B6 Struts & Shocks, BMR 1.25" Drop Springs & Adj Rear Bar, Pegasus Solid Bushings, Z/28 Wheels, other misc parts.

06-09-2025, 07:51 AM	#3
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 3,029	I have 3.73s with a turbo and it smokes the tires in second on the street. Any more gearing would be useless. I run a 325/30/20 Sport Cup2 on the street. PD blower would be even worse for traction. You could run a drag tire on the street for more traction, but handling would be ruined. If you drag race, it also has to do with where you are at the end of the quarter. You would not want to be trying to shift to fifth at the end of a run. My car is at the top of fourth at the end of the quarter. Now if you are into drifting on the way to the grocery store, gear away. __________________ 2010 SS - Kind of an On3 kit, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1 brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. Gen6 ZL1 brakes.

06-10-2025, 06:22 PM	#4
SSE 4 2SS Boosted Moderator Drives: Bone Stock LS3 Join Date: Sep 2009 Location: Marion Tx Posts: 15,798	I went the other way with gearing due to my choice of racing.... I went with 3.07 gears, and a slightly different ratio in the transmission, and yes I could smoke the tires in 1st-5th gear, almost at will... Which is why I ran a very good traction control system. ProEFI Turn it off and do 200+ mph burnouts in 5th gear... It was interesting to say the least... Traction is the biggest reason people avoid gears in the 4.XX or more range. For a few as was also mentioned it's the potential highway RPM range... However, the 6 speed transmission does help with that... This isn't the 70's or 80's with 4 speed transmissions... As for overheating a forced induction system on the highway, you are typically making little to no boost as cruise throttle settings.... If you pulley down to spin the blower faster, you might minimally create some heat in it, but again, as cruise throttle positions there is often no boost being created, you're just spinning it a bit faster with "no" load... __________________ If the car feels like it is on rails, you are probably driving too slow. -Ross Bentley Horsepower is how fast you hit the wall. Torque is how far you take the wall with you. “If everything seems under control, you're just not going fast enough.” Mario Andretti If you can turn, you ain't going fast enough...