NASCAR gear tuning

Can someone show me how to tune the gears for the nascars? I’m having trouble tuning gears since I don’t mess with the gears in all my cars…

I have only tuned 4th gear and final drive, will have to check when I get on and give it to you…I actually tuned #11 FedEx to do 232mph just adjusting those 2 gears.

It really depends on what track you would want to run the car, so, you might want to have several options available. Most of the time folks focus just on adjusting the Final Drive. You must first decide how many gears would like to run at a particular track. If the default gears along with the selected FD make me either needing to up-shift near a tight turn, then, I go in a and tweak that particular gear. There are a couple of write-ups on the process…I believe on FM5 tuning area. And, several articles on the web which I read through awhile ago and can help you on this topic.


The best way to tune the gears for a certain track is to first run the track in question. Make a mental note on your top speed at the end of the longest straightaway, and adjust your Final Drive Ratio to reach that speed just before you hit the rev limiter/red line.

If you want to use all 6 gears in a six speed car, adjust the FD so that gear six will hit the red line at the speed you want to go.

If you’re only wanting to use 4 gears (which is what the NASCAR Cup cars have and can’t be changed), then lengthen fourth gear to reach that fastest speed. Note, that if you lengthen fourth gear, you should lengthen all gears to keep the RPMs within the power band at shifting point. Here is an example: Say the max torque of the engine is 350 ft-lbs @ 6500 RPM, you don’t want to lengthen fourth gear without lengthening the others. Because, when you shift to fourth gear, the RPMs may drop to 3500, and that may be too low for the engine to efficiently power the car back to the power band. This is what is called the “Torque Curve”.

The best way to use the torque curve, is go into the upgrades section and go into the engine. Now select a part and look at the graph. The torque is the blue line, and you want your RPMs to be within that hump, or curve for maximum engine efficiency. The rule of thumb, for me anyway, is to shift at the end of the curve, and try to have the RPMs in the next gear be at the beginning of the curve (when the torque has less of a gain, but still has a gain), then up shift at the end, right at the point the torque begins to fall off. Using the telemetry will help, when test driving or racing, learn when the best time to shift is. But note when tuning each gear, you don’t want the bottom of the lines on the graph to be straight across. You want the highest gear you’re going to use to be higher than the rest. Second gear, needs to be at the beginning of the curve, and gradually higher for each higher gear.

The main reason to remain in the torque curve is so the engine doesn’t get bogged down in the next gear. I’ve used tunes from other people in the past (Forza 2-6) that the shifting points are horrible. Meaning I shift at 6500 RPM like I should, but the lowest RPM in the next gear is at 2200 RPM when it should be at 3500 RPM. And the acceleration suffers big time from that.

But if all of this info is confusing you, just stick with the Final Drive, and have whichever gear you’re going to use at the high gear hit the red line on the Tach at the end of the longest straightaway.

Nice post sir, but regarding the NASCAR setup as the OP mentioned.

1: A NASCAR tuned to P900 should be running 907hp and 717 lb ft torque, though a 4 speed race box, ( no six speeders available at this time ), never have 4th gear higher than 1.0 as is will act as an overdrive and therefore degrade acceleration on oval and fast road tracks.

2: Some tracks will only require 3 gears to be used, so tune accordingly, ie Sonoma as it has very short straights. Although you can use a forth gear on the long circuit if so desired.

3: As mentioned in para 1, the torque is very high, TCS is highly recommended as you will spin cold tyres up very easily, at the start and even when hot it’s easy to lose the back end until you get proficient in the car.

4: Tune you gears so that as you exit a corner and you need to change up, you don’t have to immediately change down again to go though another corner ie turn 5&6 on Sonoma NASCAR track, don’t forget the torque on the engine is maxed at only 5000 rpm, so you can use the flexibility of the engine, the HP maxes out at the redline, which cannot be used at all as it could in Forza 4.

5: The brakes, I’m afraid that without drastic changes to wheels and tyres, you will only have stock brakes, obviously this will mean a complete re-tune of the suspension setup.

Unless you are really competitive you will find that once you have a good general set up, it will work on more than one track, maybe a little tweek here and there.
These NASCAR’s run very differently to the Forza 4 cars, and as the pack has only just been released, the community is still fiddling around looking for that little bit more speed.

Good luck, and most of all, have fun.

Thanks for the compliment. And good work posting stuff I overlooked, or didn’t have space to post it. All of my info for the most part is in general, but works very well with the NASCAR group.

But, if the OP is running in NASCAR World Tour, they won’t be able to use the R900 build. But in Multiplayer Hoppers and Leagues, they can, and are advised to, by me. lol… Because if you try to use a
R833 car, then you’re going to get waxed as the R900 builds have nore power and torque, and over all better handling… Unless you’re really really good at driving the 833 cars, which I am not, you won’t do as well against a 900 car. The best driver in the world in a 833 car may have a shot at the win against a 900 car, but a lot of that is due to experience and/or a really good, stable setup.

To OP, throttle control is also something to take into account for tuning gears. And also, whether or not you use Manual with Clutch. If you run manual with clutch, you may want your first gear a little shorter, moving the slider to the left a it, so the car doesn’t stall at the start of a standing start race. That makes no difference in a rolling start race, nor if you’re using Automatic or regular Manual. But all of my advice and info, is from using Manual with Clutch, and my 20+ years as a mechanic, big NASCAR player and tuner, and all around car guy.

Does that mean my tunes are some of the best in the Forza community? Not even close, as I like a more stable car, with shorter gear ratios (except at Daytona) to get out of the corners better. My tunes are mostly for career anyway, as they are slower. I get lucky sometimes in Leagues and bag a win or two with my own setups. But I use other people’s tunes mostly, which are not tuned for the track I am racing at, most of the time. Most of them are general all around tunes.

But, back on topic here, your gear ratios are only as good as the rest of the setup collectively. You’ll want a good stable tune (that fits your driving style) to be able to achieve the fastest acceleration with the tune. For example, letting up off the gas for s plit second on corner exit kills your acceleration, so you’re basically starting from 0, at whatever speed you were going when you smashed the throttle again.

And Rear DIFF settings go hand-in-hand with the gear ratios. If you have the rear diff lock too quickly on acceleration, you’re just wheel spinning, not gaining any time. Losing time, actually. Same goes for decel on corner entry. Having the right gear ratio gets a good rpm range for the corner, but if your decel setting is too high, it’ll take some of those rpms away quicker than you want. So, for the NASCAR cars, for proper truest to real life handling, I’d leave the decel at 0. And maybe crank up the accel to 60-75%. If it has too much wheel spin, back it down a little bit. Your rear springs dictate where your lowest accel settings can be without major oversteer when smashing the throttle.

That’s my 2 cents for the moment, hope this all helps a bunch. Remember, your gear ratios are only as good and as fast as the rest of the tune will let you go. If it’s unstable, it’s not going to be as fast. Going out into the grass, or into a wall on corner exit, you’re losing speed there as well.

As you can see there is no mention of tuning for the seasonal races jteark, I naturally presumed that he was referring to multiplayer tunes.

As regards for the decel setting on the diff, that’s not easy to answer. Firstly, you are quite correct, leave it at 0%. Until you are absolutely sure that everything else is running as you want it.

Then stick it on 50% and note the difference, then 25, then 75, do not use 100%.

Play around with the car a bit, just make sure you keep 2 copies of your hard tune, reason being that if you do forget to save, you got a back up, I forgot this and it cost me 2 day’s retuning.

And just a mention to you budding tuners, the are so many cars in the NASCAR garage now, that unless you have an exceptional memory, it’s hard to know where you tuned a certain manufacturers car for a certain track.

The tunes are not transferable between the same garage, The tune you made will only work on that particular car, please bear that in mind when naming your tunes.

As you don’t use first and second gear very often in an oval race, you might want to use the classic tip having the third gear as a final gear for running alone, and fourth gear as a drafting gear. Very common in Nascar, and oval racing in general.

Works great in FM6 too.

You push 1,2,3 gear up high, so that you allmost rev out before taking the corners in third, then place your fourth gear close to the third ,for drafting.

If you’re in a race, and you lose the draft, then go from 4th to 3rd, to get some more power.