Camshaft upgrade or Exhaust upgrade for C class?

I’m wondering which one will be better for the C class racers in multiplayer if the exhaust does anything it lets me get a backfire and better sound the cams have less limiter and more RPM’s to rev.

Test drive the car with each on. If you do, im sure you’ll decide to go with exhaust.

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A cam will indeed aloow the engine to rev furthe however without appropriate ignition and or fuel increase the gains from a cam alone are nominal, however the gain froma exhaust doenst need any other upgrades to get the all off the upgrade, it make the engine bay lighter increases exhaust flow therefore increasing throughput and gives you a glowy pop as well, to me its a no brainer exhaust all the way, by the way as a rule I dont use cams unless I absolutely have to, instead increasing exhaust first then displacement then compression then ignition then fuel then air before moving to aspiration - all before putting a cam on. good luck

Alot of videos I have watched people do aspiration or engine swaps first. Is it always better to upgrade the engine components first?

Most know what engine they want to use for a build, before they even start. Yes engine swap first. Adding engine upgrade next NO.

99% of the time i dont do Cams. Reason being it costs to much PI for what its worth. 1st i will try a centrifugal supercharger. 2nd i will try exhaust. Most of my cars have those 2 in them to get the most out of the car for least amount of PI

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There is no quick solution to tuning…Every car reacts differently to different upgrades, the only way to find out what is best is build the specific car u want, then run a few laps and remember your best time and save the build…Then do the same with a few different builds ie supercharged,less grip more power,cams,exhaust,engine swap…its only a matter of time till u find out what is the quickest build, then u can delete the rest and fine tune the one u like … simple…

Cams are 99% of the time completely useless, as they increase speed stat a lot most of the time, and pi overrates speed, therefore it costs a LOT of PI.
Basically you can think it this way
do you want. If we give base cost of 30PI. do we want to get
A. 45hp, 15lb-ft
B. 40hp, 35lb-ft and -20lbs on total weight.

A. being the camshaft, and B. being exhaust and something else.

I would go for B always. Using camshaft only when there isn’t other way to get the car in the PI limit I want to get.

Isn’t that only from F4?

Cams some times works for me ( and that cannot be wrong).

Cams can work if it give more power per PI/weight than other engine upgrades (not including C super charger) AND works better with the gearing (stock gearing or not).

From FM2 onward. Go ham with the cam. Out of 200+ cars in this game maybe 5-6 benefit from the cam.

As a general guideline for a multi-track car I’d agree but I’ve got more than 6 in my garage with a cam upgrade over something else on my track specific builds. All to get more average Hp when using the stock trans. I’ll start with the stock cam but I’m not afraid to waist a little time looking for the exception. I quit speculating and just started building everything and taking it over to the Mulsanne strait to map it out. Found a few surprises along the way.

Crash’s guidelines for engine building:

  2. For the allotted PI - Maximize average Hp/weight between shift RPM unless you are approaching terminal velocity at which point it’s all about the power.
  3. See rule #1, Build it, Race it

For 90% of circuits I would go with exhaust plus maybe air and something else rather than cams.

With a few cars on Le Mans old I would test cams.

Care to elaborate? Logically adding a cam and driving down a straight cars would more than likely be faster in terms of top speed. What else have you found?

Not looking for top speed. Simply running in top gear on a long strait to record the Power as a function of RPM. I also do coast down tests to calculate drag coefficients and equivalent flat plate area so I can make some decisions about aero settings but that’s more just because I can. Actually top speed will be dictated by the gearing and either the small cam or large cam engine could logically result in a higher terminal velocity. The big cam car could suffer from hitting the rev-limiter in 3rd gear making 350 hp at 120 mph when it only takes 320 hp to overcome drag leaving the 30 hp available to accelerate wasted. When you shift to 4th and drop 1500 RPM the engine is only capable of producing 300 hp so the car slows down. The small cam car could hit the rev-limiter in 3rd gear making 350 hp at 100 mph when it only takes 290 hp to overcome drag and when you shift to 4th you have 10 excess hp to accelerate and power available may exceed power required all the way to 125 mph where all 350 hp is needed to overcome drag and the car no longer accelerates. DISCLAMER - numbers are totally made up to make the example simple.

Question: What have I found?
Answer: Peak HP and the power curves on the build screen are complete fiction.

EXIBIT A: 87 Pontiac Firebird built to D400 (OP was for C class, I think in C I ended up with the race cam in 3rd gear but I have the D class notes readily available)

There are at least 4 different combinations of engine parts that result in an advertised peak power output of 290 hp and build to a PI of D400, probably more. All other parts remaining constant.

Engine#1 Big Cam - Street Centrifugal Supercharger, Street Cam, Stock Exhaust, Street Displacement, Sport Head, Street Intake
Advertised output of 290 hp at the rev-limiter with an estimated 252 hp @4000 RPM
Total car weight of 3,547 lb

Engine #2 Small Cam - Race Centrifugal Supercharger, Stock Cam, Stock Exhaust, Street Displacement, Sport Head
Advertised output of 290 hp at the rev-limiter with an estimated 260 hp @4000 RPM (more hp than #1 across the entire RPM range)
Total car weight of 3,533 lb (15 lbs 0.4% less)

No Brainier – Engine #2 weight reduction helps everywhere breaking, turning, and accelerating. Even if it only made 288 hp it would still be better but it makes more so duh.

Hold on Cowboy what’s this? Engine #1 is easily 0.2 seconds faster around Indy Oval – WHAT? HOW?

Engine #1 Big Cam real output (per telemetry)
286 hp @ 4,000 rpm
290 hp @ 4,300 rpm
292 hp @ 4,900 rpm at which point hp starts to drop and doesn’t increase towards the rev-limiter as advertised. +2 secret hp

Engine #2 Small Cam real output (per telemetry)
283 hp @ 4,000 rpm
287 hp @ 4,500 rpm
290 hp @ 5,000 rpm at which point hp starts to drop and doesn’t increase towards the rev-limiter as advertised.

It was actually a mistake that I even ran Engine #1 since it was clearly inferior. When I first saw this I assumed I simply loaded the wrong file or mixed up my notes but I can assure everyone that I have verified it more than 4 times this evening alone. Engine #1 looks like what I would expect from the smaller cam not the larger one. Are my files corrupt? Did the game glitch? Engine #1 makes 4.0 boost and #2 makes 12.0 boost consistent with the supercharger upgrade.

Engine #1 exits turn 2 at 131 mph making 286 hp @4000 rpm and accelerates to enter turn 3 at 149 mph and starts producing 290 hp @ 4,300 rpm halfway down the strait.

Engine #2 exits turn 2 at the same 131 mph but only making 283 hp @4000 rpm and only accelerates to 147 mph where the engine is still only making 187 hp at 4500 rpm.

With an average of 3 hp more across the entire RPM range Engine #1 could potentially make up for the 0.4% weight penalty on every track. I’d run both just to make sure. I haven’t even tried Engines #3 and #4 yet. What about engine #5 with the Race Exhaust that only advertises 279 hp? Does it really make 283 hp at 4,300 rpm but weigh 97 lb 3% less? It at least has the stock cam. What if I trade hp for more grip and I could exit the corner @135 mph and only accelerated to 145?

I’m secretly hopping its a glitch because now I’ll never feel like I have found the best engine much less the best build,

Higher possible RPM, Assuming that you have same exact gear ratios, therefore it is rather obvious that the car will be faster around oval. Same thing as if you would put longer final drive. Therefore I’d say this is irrelevant.

It is possible that camshaft is faster on one straight, I’d say that it’s actually quite highly likely, that one random car is faster on some random bit of track with upgraded camshaft.
How about around a lap of that track.

So far you have mentioned.
Old LeMans where camshaft is extremely beneficial if you use stock gearbox on low class car, as it SLIGHTLY shifts the peak power further up the rev range, and the car is less likely to top out because of gearing.
Indy Oval the same thing as LeMans.

How about lap around LeMans Bugatti Circuit. Or better yet, Lap around Spa, or Lap around Yas Marina.

I’m pretty sure that in the end Centrifugal and Exhaust combination would win. That is, unless you need to lose some power to get grip.

I use cams over other things like displacement, etc for the following reasons:

  1. Driveability - Cams don’t add much to torque but do give more high end power, I’ve always liked to run my cars at fairly high rpm (8-9k+), you’d think that getting less torque would be a bad thing but I’ve found it makes the car much nicer out of corners and i’m really able to step on the throttle without fear of overloading the rears.

  2. The sound! - everybody loves high reving engines, enough said.

  3. Top speed - i’ve found myself getting outdragged at the start of straights only to pull them back in towards the end of the straight, i’m not sure if this is a function of the cam or if it’s because I don’t run aero parts on my car.

The main thing though is the driveability, i’ve tried many different builds of the same car and I always favour the build with the cam, I just find them much more user friendly and i’m able to carry far more speed through the corners without the rears breaking loose.

I’m sure this is because I have less torque and that power delivery is smoother, for that reason I rarely have a turbocharged car because the power delivery is sudden and sharp and doesn’t fit my driving style.


Irrelevant if you are looking for laptimes, and by the way, Everybody does not like high revving engines.

This is cause of the wings, Other cars can corner faster than you, but for the very same reason they can’t go as fast as you do.

Actually you are doing pretty much same speed, you just aren’t smooth enough if you have more torque. = Throttlecontrol / possible tuning issue on differential.

True in matter that turbo’s are rather useless, as they add power to middle of of the powerband and it delivers it very sharply. Twinscrew adds everywhere the powerband so you use only 50% of the added power, and Centrifugal which takes away from the bottom of the powerband (where it’s useless), and adds to top of the powerband where 100% of it comes in good use.

  1. I have throttle control but some cars simply have unwieldy amounts of torque, for example, build a RWD syclone with the racing V8 derestricted to 1000hp and tell me any amount of throttle control could make that drivable, clearly that’s an extreme case but it equally applies to cars with above average torque figures on corner exits.

  2. Tell that to those complaining about F1’s new sound… and laptimes? is that all anyone cares about? what happened to racing cars that you like.

  3. Hmm, true to an extent although the power being shifted to the high end does help if you’re running close to the limiter at the end of a straight.

  4. Back to 1 and on the differential note, I don’t doubt it but I have limited time in which to play so I can’t devote hours to setting up a car like I used to back on FM2/3/4

  5. Well we agree on something!

  1. Extreme case, but we can also come to conclusion that that sounds like drift car. just simply too much power in every scale, Same thing as Hennessey Venom. Fun car, Definately FAST car, but too powerful for being fast around a track, unless you are looking at LeMans, or dragstrip.

  2. At least I don’t get headache when I’m watching F1 races anymore. But sure I like how Honda vtec sounds.

  3. True if your gearing is set up so.

  4. This might be true. and that’s something I cant judge.

If you take restrictors off a car you can’t tell the difference in cams or not as it isn’t even an upgrade.