I know the tune is off now, but even when it was spot on, the AC would cause RPM drop enough to be noticed.

 

There is literally a single table in the PCM that would have resolved that In EFI Live I believe its known as AC torque loss.

 

Lol guess that's what I get for letting a shop convince me that they were better than Nic.

 

LOL plenty of shops out there fooling people, but also plenty no names out there who actually know how to tune a car. Nic and I have gone back and forth on here from time to time, but I respect his tuning ability.

 

From the few tanks I tried, e35 seemed to be best for my set up

 

Nic is far and away the best out in mesa/chandler/Gilbert area. He did my first few tunes. But his real value was that I had two major mechanical issues that he diagnosed. One was a cam that was ground nine degrees off and the other was a shitty y pipe with plugged cats.

 

Yeah, those would be the turd in the punch bowl.....

 

Was that a Comp Cam from back when they that batch of bad cams?

 

I agree. I'd venture to say he is the best in AZ. I made the mistake of letting Gearhead Garage (went under years ago) talk me into their "lean cruise mode" tune and re-flashing the ECM to 2002. It ran fine, just stumbled a little when the AC came on. Had Nic re-tune it when I had to get a new throttle body, and there was an electrical issue that made the O2s act weird, and the Dyno equipment seemed to have some electromagnetic interference. Turned out to be a bad ground. I figure I'll just wait till I get the heads and new cam to get it re-tuned.

He even took a look at the 99 TAs tune when I first bought it in 2006. Fixed a couple of settings that the previous owner had screwed up for free.

 

Yup. It was before I knew anything. Just threw shitty parts at the car. Worst build ever

 

Its all tuning man. My friend and i are running similar cams and our cars run great all year round. Mine was a little tougher to tune with the fast 102/102 but its completely doable.

 

+1 for NicD. I won't go to anyone else. I dont know how you are comparing cylinder heads but there is way more to it then dividing provided flow rate by port size. There is no standardized method of testing for airflow in a given port. Most companies use different benches. Some more accurate and expensive then others. What the ported ls6 heads lack over the aftermarket counterparts like the prc 225s is airspeed and deck thickness. The prc should walk all over a ported ls6 and are a great option for those not looking to send in their ls6 heads and wait weeks (extra downtime) for them to be worked on. Also, consider you could sell the ls6 heads for 400-600 bucks. So these 1800$ prc heads (factoring hollow intakes) are the same price as porting the ls6 heads but you have a superior head. I have talked to tsp numerous times regarding these heads and they assured me it would make more power then ls6 heads and are within a few cfm of the 227 heads. They also give the option for large bore or small bore applications which the 227 didn't seem to offer. Bigger port heads may have increased flow all over the lift range vs smaller port heads but could lack power production below the curve because it cant move air efficiently enough to feed a head until the upper rpms. Would a 247 head on a bolt on cam ls1 be faster then a 227 in a street car? I dont think so, not until way up in the rpm range and even then you may not have enough cubes to utilize the flow potential up top. This is an extreme example but the principle still applies.

People like to talk cams all day here but even more interesting imo is heads. So much more power to be made with a proper head choice for a given combo then a cam, it's the most important part of a performance engine build. We need more cyl head discussions and theories.

 

Me either. Just sucks that it took me about $400 to learn that lesson. lol.

 

To oversimplify. First there is the flow demand for your power level. Then, the smallest port that can possibly feed it. Velocity is king. Darin Morgan, Greg good, Mamo, all of them will tell you that. Problem is how as an end user we can determine velocity.

 

To determine airflow required at peak piston velocity at a given rpm we can use this formula:

(Cid × rpm).000978474 / # cyl

But in regards to airspeed, well the manufacturers keep their designs a secret so we use data acquired in forums such as this to make an informed decision. Just need to be smart enough to know what good information is.

 

BOOM. This is gospel as I have learned from loitering around here the last 3+ years. I have learned that you get the heads for your engine displacement/power goal, THEN get a cam that feeds the heads (in a nutshell). But cams ARE fun to talk about, once the heads are decided on....

 

I agree. Now I just need to decide what heads I want. I have at least decided that I am going with aftermarket castings. I really think I am down to AFR 230 or AI Dart 223 heads.

 

Prc 227 heads are a good option as well. May go on sale here soon too. Bonus is you can run factory rockers with bronze guides and save some money there. They also have as cast 225s for even less money for a negligible hp difference. Both have thicker decks.

 

I am not going to do as cast heads. If I am spending this kind of money, they are going to be fully CNC'd. The price of the PRC 227s with comparable springs is less than $200 under the AFR 230s, and $100 over the AI Dart 223 heads. I just cannot see myself picking PRC over AFR and AI Darts.

 

AFR heads are gold in my book from what I see them do. The ONLY downside, unless it has changed, is that you must use roller tip rockers to prevent side-loading the bronze guides.
If they have gone to powder metal guides either standard or as an option, then disregard the above.