Well, Andrew (Dyno4mance), Paul (RallyRedEvo), and myself did a little bit of independent cam testing this weekend. It wasn't uber scientific, so the results were far from conclusive.

Anyway, I had 264i/264e and Paul had 272i/272e. We switched exhaust cams and dynoed then retuned. From what I made three weeks ago, my curve was identical, but power was down about 3whp globally due to heat, humid shop conditions, etc. No gain or loss anywhere in the powerband whatsoever from what I could detect.

Paul got a little more torque with the 264 exhaust cam, but he hasn't dynoed in awhile, and it required a lot of remapping as well as the fact that we tried a lot of different cam gear settings, so those results were inconclusive.

Thanks for listening. IMO, 264s are good enough, but I'd like to test some 280s!

 

were the tunes off any before you swithed out the cams? I think my car is still running good as I put down the same trap speed of 109mph like I did last november. (still need to get better at drag racing)

 

303whp pump, 324 race recently.
300whp pump Saturday.

If it didn't trap at least 112 pump and 115 race, I'd cry!

 

I'll let you run my car for me then

 

Where was this "little more torque" obseved at? Rev range, WOT or spirited city driving type conditions.

Thanks for the report

Do you have a dyno overlay of the base tune vs. cam swap tune of either cam combo?

I have been considering going the 272In/264Ex, but havent found any conclusive data stronlgy suggesting the effort. I am currently running the 264's @ -2 on 91 oct.

 

Noize, What cam setting did you try?

 

3800-4800rpm


Not handy. I could get one for my car, but the onefor Paul's car has different cam gear settings as well as a complete retune, so its not a fair comparison

I'd stay with what you have. I don't think you'll see any noticable gain whatsoever with just moving one cam from a 264 to a 272. The lift is the same, and 8 degrees of duration doesn't seem to make a hill of beans difference.

264i/272e. Cam gears still at -2/-1. Still really happy with the results.

 

Exactly what I found when I tried 264/264, 272/264 and 264/272 last year. Pretty much no difference. If there was any difference, it was in the nosie. Glad to see it confirmed that 272/272 was the same, too.

Attached is my excel spreadsheet from these tests. Scroll over to the right on the first page to see the interesting graphs. Ignore the 118mph run data with the 264/264 combo because it was extremely cold that day which skewed the data.

Oh crap, the file is too damn big. I can email it to you if you want. It is just airflow vs RPM data for 3rd gear on a few 1/4mi passes for the 3 different cam combinations.

 

Hit me at shester@gmail.com please, Josh. Thanks!

 

Noize,

Is there no difference between the cam combinations because at you and Paul's level of mods the difference will not be evident? I am wondering why HKS would make these different cam combos if they essentially produce the same results. I am wondering at what level of mods you would see the differences in the different cam combos?

I am thinking of getting cams next and there is so so so much misinformation about the combinations that it makes a decision really tough. I would like to have quick spool and a wide powerband from 3000 - 7500rpm with good low to mid torque. Basically a street only car. Any suggestions?

Thanks for a good post!

 

Well, you really cant go wrong with either 264/272, or just straight 272's.

 

I would like to see that file too. Could you please e-mail it me? anzario@hra.com

 

The different cams start coming into play when a turbo kit is added, or on race gas maps. *sometimes*

The car that held the stage 1+ record for a long time had 264s.

Noize, good work man...When are you comin out to visit?

 

When his wife cuts the apron strings and he can crawl out from under her thumb...

 

Shat!! The same thing that's stopping me from going out there is stopping you too, sucker!