My crane 12 thread (updated periodically)

[phillysrt4]

RESULTS ARE IN!!! scroll down to see my report. I think I still have some more tuning to do, as I incorrectly remembered the "sweet spot" most people found with 12's (3 degrees adv intake, 4 deg retard exhaust. im a degree short on both counts)

Lucky you guys! Im only making this thread on srt-4mation and srtsyndicate so you guys get the inside scoop on my crane 12 experience.

Well, the crane 12's are in. I had a chance to put some miles on them and here are my initial reactions.

There is dispute as to how the cams feel between idle and 2500 rpm versus stock cams. I had a gearhead in the car and he said that not only could he feel the lope of the 12's, but he said it didnt seem as "torquey" way down low. Personally, I really cant feel a difference at the bottom. One thing we both agree on, though, is that there is definately a pickup in torque once you get above 2500 RPM. It is so much easier to create wheelspin on these cams in 1st and 2nd! I currently have them dialed 0 intake 0 exhaust and there is still a hint of a loping sound at idle which I really like. The exhaust tone has also become more "agressive" versus the stock cams. I think there is a tangible change in the tone with these cams in.

The other nice thing about these cams is I have improved fuel economy. I went through a tank of gas on highway driving and despite sections where I went north of 90 as well as some moderate jamming to get around slowpokes I was able to get 27mpg (11.37km/liter) on a 75-80mph (120-130kmh) cruise. This is the in the range I was getting when I was babying the hell out of the car doing a flat out 75 (120kmh) and slower. When the novelty of the cams wear off I plan to do a gentle highway ride and see if I can finally crack 30mpg (12.6km/liter).

While we're on highway driving, I gotta say these cams really shine! If the RPM's are at 3000 or more, there is no need to downshift to get a nice push into the seat. I feel I have to downshift less often with these cams in than when I was stock. It probably wouldnt be far from the truth that, once im above 3000rpm, the car on pump gas feels almost as fast as when I was in HOM on stock cams.

The only downside (and Im not 100% sure of this because my gauge went wacky AGAIN :( ) is that boost seems to fall off a little more near the top end. Instead of a 17 peak with a fall to 15 from 5000 to redline, the fall seems to be to 13-14 and it starts a little earlier (around 4800). I cant say for certain if the boost reading is accurate, though, so take this with a grain of salt.

All in all, I'm very satisfied with the mod. Unlike other mods such as WGA or PCM changes, piggybacks, etc, this is a mod that will always complement anything else I do with the car. I'm looking forward to getting on the dyno and reporting back some baseline numbers as well as final numbers and sheets once I get them dialed in the way I want. Since so few people do a cam upgrade with the relatively small amount of power adding mods that I have, I hope that my findings on the dyno will give people some real-world data of just what these cams will do for you in terms of gains on a car.

Stay tuned for more updates.

[Stage-1-SRT-4]

cool:jester:

[el_jefe]

I want cams. . . . .

[phillysrt4]

I want cams. . . . .

you wont be disappointed if you do get them.

[el_jefe]

you wont be disappointed if you do get them.


Oh, this I know.

[phillysrt4]

^^^ then get them already! :)

[phillysrt4]

Introduction:

Many people consider cams as a way to gain power. Unfortunately, there is little data about cam performance when other modifications are minimal. In this report, I will discuss the results of my camshaft modifications adjusting them with cam gears and discuss my conclusions with respect to this mod.

Apparatus:

The car is a 2004 Dodge SRT-4 with the following mods that may affect performance:
1) Mopar Stage 2 with toys
2) Mopar Cold air intake
3) Borla (mopar) exhaust
4) Crane camshafts part 193-0012
5) Fidanza Cam Gears
6) Mopar Blow off Valve

The car was tested on a dynojet dyno using SAE correction.

Procedure:

The car was run in High Octane Mode (HOM) in order to get a baseline pull. After baseline, the following combinations were tested (intake/exhaust):

1) 2 degrees/0 degrees
2) 2 degrees/2 degrees
3) 2 degrees/4 degrees
4) 2 degrees/3 degrees
5) 3 degrees/3 degrees
6) 1 degree/3 degrees

Following these adjustments, the cams were then dialed 2 degrees/3 degrees and a pull on pump gas was performed.

Results:

Due to a tach sensor malfunction, we were unable to get an accurate baseline. As such, no charts will be provided. By interpolating five runs using the best results for each at a given RPM, we concluded that the peak numbers were approximately 255whp and 289wtq. This is down from the stock cams (265whp and 303wtq). However, we noted that slight gains (approx 1-5hp) were made between 2500 and 4700 rpm. The intake cam was then adjusted 2 degrees advance. The result was a minimal peak gain.

However, we were able to get a solid tach signal, and thus pressed on with adjustments.

We noticed more gains were made by adjusting the exhaust cams versus the intake cams. After adjusting the exhaust cam to 4 degrees retard (2 degrees advance intake), we achieved our best peak HP number (268WHP) however, we did not get great numbers above 5000 RPM. This setting gave less top end than the baseline settings. The best compromise, which gave great midrange with minimal top end loss, occured at 2 degrees advance intake, 3 degrees retard exhaust. Additonal observation of the graphs did show that these cams produced peak power lower in the RPM band, anywhere from 100RPM to 500RPM below stock levels regardless of cam adjustments.

The following graphs show a comparison of high octane mode on the stock cams versus high octane mode on the crane 12's with 2 deg advance/3deg retard. Blue line is stock, red line is crane 12's. First, the torque graph:

http://i10.photobucket.com/albums/a132/phillysrt4/2adv_3ret.jpg

As you can see, there is a slight loss in peak torque, but there is a gain over the stock cams between 3200 and 4800 (with a small 100rpm exception). As the graph shows, there was a gain of 13 torque at one point on the graph. Now, the power chart:

http://i10.photobucket.com/albums/a132/phillysrt4/power_2adv_3ret.jpg

Again, a gain of 16whp was seen at one point.

Now, to pump gas. First, the torque curve:

http://i10.photobucket.com/albums/a132/phillysrt4/pumpgas2adv_3ret.jpg

This is where these cams really show their worth. Note the unquestionable gain in torque between 2800 and 4800 RPM. The line shows the peak difference between the cams. This translated into the following power curve on pump gas:

http://i10.photobucket.com/albums/a132/phillysrt4/power_pumpgas.jpg

Again, a slight loss in peak power, but nice gains in the midrange. The line shows the greatest power difference.

Conclusion:

The purpose was to see if the crane 12 cams would make a difference with minimal modifications. As the results show, there are mixed results. If you are looking for peak horsepower gains, additional modifications or another camshaft choice may be required. It also seems clear that the cams had a better response to the pump gas map than the high octane map, although additional testing on pump gas may be required to verify this. One thing is clear, this gain in the midrange may be what I was feeling when I said it "almost felt like HOM" in my previous postings.

Another thing to consider is ambient conditions on this. The first graphs were done in october and with a boost leak causing fluxuations in boost. The boost this time was more consistent (albeit not perfect) but it was 20 degrees colder out. It seems to be general knowledge that as temperatures get cold (today was a 40F day) the PCM provides less boost.

This may explain the changes in the curves, and also explain why I felt gains in driving the car after the cams were installed. Additional testing may be required.

EDIT - Turns out that my air filter was dirty as hell and I had another boost leak I didnt know about. These two things may have resulted in a loss of power. This would explain why my SOTP dyno registered a gain but the dynojet may not have. My SOTP was comparing crudded up intake to crudded up intake, whereas the dynojet was comparing an air filter only about 3k into service versus one that was clogged to hell.

EDIT - Finally, it should be noted that in many places there was a torque gain despite having a richer air/fuel mixture. Perhaps some type of fuel management will be required in order to see what these cams truly do given identical air/fuel ratios.

Summary:

I still like the mod. Of course its depressing to see that your dyno charts dont agree with the seat of your pants, and the talk of "you'll gain 15-20hp with boltons" doesn't pan out. The thing is, I dont have all the "boltons" that they may be discussing. It may be that I need to get a TB, o2 housing, a port job, etc to really make these cams shine.

Despite the graphs, the car still feels like it pulls harder (ive had independent verification of this), and the torque graphs seem to confirm it especially on pump gas. All in all, I still recommend a camshaft and gear modification. Dont expect to be queen of the dyno after installation, but do expect to feel a better pull in the midrange and more enjoyment from your car. I hope the midrange torque will help shave off some time in my quarter mile come spring.

[phillysrt4]

Appendix:

For your enjoyment, here are some torque and power graphs of various timing changes in High Octane Mode.

First, 3 advance intake, 3 retard exhaust. Torque:

http://i10.photobucket.com/albums/a132/phillysrt4/3adv_3ret.jpg

Power:

http://i10.photobucket.com/albums/a132/phillysrt4/power_3adv_3ret.jpg

Now, 1 advance intake, 3 retard exhaust. Torque:

http://i10.photobucket.com/albums/a132/phillysrt4/1adv_3ret.jpg

Power:

http://i10.photobucket.com/albums/a132/phillysrt4/power_1adv_3ret.jpg

[phillysrt4]

Also, if anyone here knows just how far I can retard the exhaust and advance the intake before I have valve issues I would appreciate it. I really got good gains when I retarded the exhaust 4 degrees but I got chicken and bailed on it and pulled it back when I advanced the intake cam.

Thanks

[gspeedaddict]

*cliffnotes i have a migraine

[phillysrt4]

*cliffnotes i have a migraine

cliffs:

1) better results on pump gas than in HOM
2) I need to do a tuning "part 2" to get the most out of them
3) IMHO, the gains you can get are worth the mod
4) Don't expect to be queen of the dyno with these cams alone

[gspeedaddict]

HOw much are the gains so far?
Sweet=worth the mod

[phillysrt4]

the graphs are above. some places got me +13whp and +14tq. improved, more consistent midrange with 2 deg adv intake, 3 deg retard exhaust

[el_jefe]

I still think that cams wont shine until you go with a stand alone.

[phillysrt4]

agreed.

plus i found out i was really wussy with my adjustments and I could have gone farther in retarding the cams

[evil j]

do you think there will be more gains once you play with the timing a little more??
ive been looking into cams my self and noticed that the # 12's intake cam isn't alot bigger then stock .
the exhaust on the other hand is considerably bigger. did you replace the springs or use the stockers??

[lunchbox660]

[b][size=3] When the novelty of the cams wear off I plan to do a gentle highway ride and see if I can finally crack 30mpg (12.6km/liter).


good post, i like all the info you put, but about your fuel economy....you should have no problem getting 30 MPG...i did it when my car was still stock, AND when it was modified. check your spark plug gap and make sure all your vacuum lines are tight. if your gap is too wide, youll waste more fuel, and if your vacuum lines are leakng your car wont be getting acurate readings so it will try to compensate for some things.

i get better milelage NOW than i did when my car was stock, its all in the tune.

[phillysrt4]

do you think there will be more gains once you play with the timing a little more??
ive been looking into cams my self and noticed that the # 12's intake cam isn't alot bigger then stock .
the exhaust on the other hand is considerably bigger. did you replace the springs or use the stockers??

Yes, I definately think there will be bigger gains if I play more. When I had the exhaust at 4 degrees retard/2 advance I had a great midrange gain but sacrificed on the top end. Next time to the dyno I am going to try going as far as 6 or 8 retard on the exhaust cam before advancing the intake cam and see what kind of numbers I get.

Since the grind isn't that much more agressive than stock, I used the stock springs. My goal over the course of the spring and summer is to get the car paid off and get all the bolt-ons installed, then go S3 with a complete engine teardown including porting as finances allow.

I expect that my motor will be around 50k miles by the end of the summer anyway, so a rebuild might be a good idea anyway.

good post, i like all the info you put, but about your fuel economy....you should have no problem getting 30 MPG...i did it when my car was still stock, AND when it was modified. check your spark plug gap and make sure all your vacuum lines are tight. if your gap is too wide, youll waste more fuel, and if your vacuum lines are leakng your car wont be getting acurate readings so it will try to compensate for some things.

i get better milelage NOW than i did when my car was stock, its all in the tune.

Thanks for the input! I think that I should narrow my spark plug gap too. IIRC I am at 38 so i might move to 35 when I do the retune. It was an expensive lesson this time on the dyno, but if you wanna play you gotta pay, right?

[el_jefe]

good post, i like all the info you put, but about your fuel economy....you should have no problem getting 30 MPG...i did it when my car was still stock, AND when it was modified. check your spark plug gap and make sure all your vacuum lines are tight. if your gap is too wide, youll waste more fuel, and if your vacuum lines are leakng your car wont be getting acurate readings so it will try to compensate for some things.

i get better milelage NOW than i did when my car was stock, its all in the tune.

I have gotten 30 mpg a few times, but I have a heavy foot:
http://i9.photobucket.com/albums/a86/orionis996/140.jpg
That was yesterday on the way home from work. I have noticed that Stage 2 gets better mileage than stock. I also have the 4603 plugs gapped at .035, but I am ready for some new ones.

[phillysrt4]

nice pic!

how many miles did you get out of your plugs. I'm wondering if my .038 gap is too wide and its pulling timing in the midrange (hence the dip in torque and power)

[Needs2Ride]

I was looking up some info on those crane 12s of yours and they are listed at being the choice for nitrous use, is that part of your eventual goal?