BTR stage 3 cam concern

[ARuiz9]

I recently had my cam install done on my 2015 1LE along with a flex fuel kit, the car already has LTs and cold air intake installed prior. The car was Dyno tuned and it put down 509 hp and 423 torque on e85, now I did a lot of searching prior to having the cam upgrade done and I've never seen anyone put down that much HP on just those upgrades, my concern is that the car was very aggressively tuned, anyone know wether that may be the case. Another thing is the mpg's dropped a lot more than what I was expecting to lose so I feel like it might be running too rich and car bucks a lot on around 1000 RPM mind you this car has 3.91 gears. Anyone have any input on this???

[scv_guy]

Originally Posted by ARuiz9

I recently had my cam install done on my 2015 1LE along with a flex fuel kit, the car already has LTs and cold air intake installed prior. The car was Dyno tuned and it put down 509 hp and 423 torque on e85, now I did a lot of searching prior to having the cam upgrade done and I've never seen anyone put down that much HP on just those upgrades, my concern is that the car was very aggressively tuned, anyone know wether that may be the case. Another thing is the mpg's dropped a lot more than what I was expecting to lose so I feel like it might be running too rich and car bucks a lot on around 1000 RPM mind you this car has 3.91 gears. Anyone have any input on this???

Your mileage dropped most likely do the E85. If you want to see your true MPG fill up with 91 and see what you get out of a full tank. As for the 509rwhp every dyno will read differently there are setting in the dyno software that can be changed to show higher HP and also lower HP. I'd run it on a different dyno and see what it puts down. for example my car will put down 750rwhp on a Dynojet and 701 on a Mustang dyno.
lastly as for the bucking, thats the characteristics of a large cam. pretty normal

[graf101]

If the car is "bucking" the tune needs to be touched up or corrected. I have been cammed for over 2 years and have never had a "buck or surge" issue on my 2015 1LE.

[Bo White]

Dynos are not the same across the country. Ive been on quite a few and have varied as much as 30hp.

[zz430camaro]

Does it feel like 509 rwhp? Thats alot from just a cam and E85. E85 is about 2/3 the gas milage of gasoline.

[WHAMMO]

Its all normal; e85 will be down on mpg a lot. Cam will surge and buck of this size on stock big tires and gearing. Mine especially bucks/surges 1400-1600, made worst by the extreme clutch I have. With all that said, I find the car easy to drive even then. Maybe ask your tuner to back the tune a bit safer, but I wouldn't think its a lot of hp there, maybe 5-10? Idk..

[marklsx]

I have cam surge at lower RPMs with my BTR Stage 3. You get used to it though, I don't mind it at all.

[ARuiz9]

I let the e85 burn out and have since filled up twice on 91 it has gone up a bit but not in the area I was expecting to be at. I'm not an aggressive driver so I was expecting a bit higher. But my concern is the bucking and the very high hp considering I told them my number one priority was the drivability wasn't chasing high numbers.

[Adriangarza40]

I have the BTR (vengeance racing) Nightfury cam and anything under about 1600rpm is all bucking and surging. Thats just the way they're gonna drive. You gotta get used to having the rpms around 2000 in all gears for them to drive really smooth

[acammer]

Sounds like a really "happy" dyno. Like these guys have said, they'll make different numbers on different dynos. My car made 473whp/433wtq on my tuners heart-breaker dyno, and then laid out 497/455 on a Dynojet a few weeks later at a dyno day. So, I wouldn't hang a lot on dyno numbers - if the AFR is safe and it doesn't spark knock, it's good to go from a "safe" perspective. What surprises me about your numbers is the torque seems pretty low when compared to the horsepower - maybe a quirk of the dyno again.

Bucking and surging at 1,000rpm is completely expected with a cam having 10.5* of overlap. Good tuning can only go so far to helping the engine run smoothly at low rpm and loads. The problem is when the airflow is so slow (throttle closed, low rpm) that overlap causes all sorts of problems, you push some dirty air up into the intake, you pull some exhaust back into the cylinder, etc. You end up with a dirty intake air charge and poor combustion as a result, that's why they idle nasty and don't behave nicely under light load.

You wouldn't have an expectation that you'd have smoothness under 1500rpm with a cam like that unless you've got the throttle pretty open. My SS3 cam is 19* of overlap, and it's not real happy under 2000rpm unloaded. I can hang it at 1200rpm with a load on it and it'll be smooth, but once the throttle closes it reminds you in a hurry it's not stock.

The MPG drop is expected, you've made everything at low load and rpm extremely inefficient. Cars with big cams often smell a bit rich because of the incomplete combustion that occurs at idle, just another price you pay to make power all motor.

One more thing to keep in mind - yes a 1LE has 3.91 gears, but because it also has different ratios in the transmission your first and second gear overall ratio are essentially identical to a regular SS with 3.45 gears, your third gear is just slightly more aggressive, and the benefit of the 3.91 doesn't really show up at all until 4th gear, which is much better than a regular SS car with 3.45s. A 1LE would need a 4.56 rear gear to match a regular SS with 4.10s in first and second. Just something to keep in mind when discussing low speed drivability of a 1LE car.

[IDEALG]

You probably won't get rid of bucking at 1000 rpm that's just too low of an rpm to be driving at with a giant cam. Bucking in a camaro above 1200 rpm is a tune issue and can be fixed. Haters will hate but i've tuned many camaros and fixed many tunes from so called professionally tuned Camaros from the internet favored shops. You can call me all the names you want i don't care anymore i've seen enough to understand that most places don't know how to Tune properly.



Secondly the best Bang for your buck is the Jannetty Racing Rough idle cam, don't get me wrong i love BTR and use them often but i've seen the most gains in camaro's with Jannetty's Cam. 93 octane 485 rwhp without ported heads



Honestly all you guys need to forget about that big number and look at your overall powerband.

[Roader]

What kind of mileage are you talking with E85? The best I can do is 16mpg on cruise control on highway and anywhere from 9-11 mpg in city

[ARuiz9]

Originally Posted by Roader

What kind of mileage are you talking with E85? The best I can do is 16mpg on cruise control on highway and anywhere from 9-11 mpg in city

It was in the low 11s, I wasn't worried about the e85 since I'm not going to be running on very often. Prior to the cam my overall mpg's was high 16s which I thought was very good considering I don't drive on the highway too often. I was hoping to be in the low 14s with the cam assuming I drive the same way, again my real concern though is that my car was tuned too aggressively and perhaps that's going to make my car burn too much fuel and make the driveability suffer.

[Roader]

I don't understand tuned to aggressively since you arnt a FI car with boost turned up. As long as the AFR is good I wouldn't be concerned. Its to hard to talk to your surge issues without seeing whats going on