Orange Peel

iTrader: (20)

Well, I got to the dyno today and tuned the car with the new AFR 225's I swapped over. You can read about it on this thread....

https://ls1tech.com/forums/generation-iii-internal-engine/532778-afr-225-s-switched-dart-225-s.html

Final numbers for now are 506.80 RWHP and 452.32 RWTQ

Now that the car is tuned, it's insane, it feels MUCH more responsive than the Darts did, even though it lost a little power everywhere from the swap, mostly due to the 1 point drop in compression, I went from probably 12:1 down to 11:1 with the AFR's, and it was 20 degrees HOTTER outside today than the Dart dyno.

Here's the graph for you, I picked up some Peak power even in this heat...



What do you think? Here's a list of the mods the car has now and it was dynoed on my 18x9.5 Privat Profil wheels...

LS2 402
Eagle 4" stroke forged crank
Callies compstar forged H-beam 6.125" rods
Diamond pistons -2cc reliefs
ARP everything
AFR 225 heads
Cometic .051 head gaskets
Fast 90mm intake
Nick Williams 90mm TB
GM 85mm MAF
Stock Waterpump
Nasty billet fuel rails with 42lb injectors
Custom Grind Ed Curtis cam 236/244, .629/.629 114lsa
QTP 1 7/8's headers
3" True Duals with 3" Borla XR1's
ASP Crank pulley
Built T-56
Moser 12 bolt with 4.11's
McLeod Street Twin clutch
Denny's Nitrous Ready driveshaft
Racetronix 255 fuel pump kit

Louie83

iTrader: (3)

Great numbers. The only thing I don't understand is why you lowered the compression when you swapped heads?

Orange Peel

iTrader: (20)

The reason is because the compression was TOO high for AZ, the 91 octane is **** and the heat is horrid, so those two things added together doesn't allow me to run much timing in the car, only about 18 degrees and that's on the edge of it starting to ping, etc.

This setup now is running 28 degrees of timing and has NO det or ping, it's perfect. I can maybe bump it a tad with some .040 Cometics down the road, but I think I would pick up more power with a larger cam someday.

SStrokerAce

iTrader: (2)

Makes sense, that TQ curve shows how much the compression helped and it's more responsive now with the smaller port and the right timing. Gotta take the trade offs. Figured you wouldn't make more power, but the lack of the heads leaking and the less detonation I think are a good idea.

Bret

offaxis

iTrader: (19)

So the darts made more power everywhere but peak. Very nice numbers for both heads but ya know what they say in every damn thread on this board its under the curve that counts. Werent you having oiling issues with the darts also ? Looks like two sets of killer heads

Jason 98 TA

iTrader: (4)

Wow the cylinder head that was consuming oil & running only 18 degrees of timing out dynoed the mightly AFR? Granted a loss of compression is definately hurting the cars performance, but I'd take a loss in compression over being stuck with 18 degrees of timing ANYDAY! My twin turbo car is running 18 degrees of timing! I think the better throttle response has alot to do wtih timing being so much more with the new setup. It's a shame we can't get a even side by side comparision, but honestly if the ported darts had of not smoked like crazy those heads would be a completely killer option! Everyone was expecting the small runner head to make tons of low & mid range power, but by the looks of this graph the larger/better flowing port actually cleaned up in the low & mid range EVEN with way less timing. It just really sucks that so many of the dart heads smoked when we shipped them. Luckily we now have this runner in a Edelbrock head so hopefully we'll have that port back up & running in no time!.


I'm glad we got you happy & back on the road Scott!!

SStrokerAce

iTrader: (2)

Jason,

Yeah I think the right port in a set of Darts will be killer. IF you do a correct velocity profile in those things they will make all sorts of power, it's not about velocity it's about the CORRECT size and even velocity.

Bret

Jason 98 TA

iTrader: (4)

Agreed.. Port size is by no means everything! People on ls1tech are typically just brain washed into believing what's posted over & over...

NicD

iTrader: (7)

This comparison is not even really a comparison in my mind. Way too many variables for a real comparison per se. The old setup was way off, much to high compression and the oil consumption. That being said, I will take the AFRs please.

Patrick G

iTrader: (14)

A point to a point and a half of compression is worth 20-30 lb ft of torque in a 402 (across the board). If the heads were exactly the same (flow-wise), you would have seen that torque and hp maintain the advantage at all rpm. The fact that the AFR heads finally caught up and passed the higher compression heads show 2 things:

1. It illustrates how much power higher compression is worth.
2. It shows how a better flowing port can offset the loss.

Once you get tired of making 507 rwhp, I'd encourage you to mill the heads and run the thinner gasket (for better knock resistance and higher SCR). As you can see from the mid-range numbers, you're leaving pleny of power on the table.

Good writeup. Thanks for sharing.

lilbuddy1587

iTrader: (1)

Very nice scotty! When's my ride ? I'm only down the street ya know!? You know I'm going through withdrawls because my **** is blown up

Jason 98 TA

iTrader: (4)

What theory did you go off of when you decided the 225 out flow the PRC ported Darts?

Patrick your completely missing half of the equation.

Your post confirms one of two things.

1.) You can't see past your love for AFR's cylinder Heads.

2.) The blue pill makes people delusional

The car has 10 degrees more timing using your beloved 225 afr head. Can you tell me you'd give up 10 degrees of timing for tops 1 point of compression? Going from 11.9:1 to 11:1 is not worth giving up 10 degrees of timing.

Claiming the power difference is all compression & completely ignoring the timing changes is completely expected, but not at all reasonable.

Just for once take a honestly look from a neutral standpoint. I understand this is not the best comparison, but the changing of compression does not give up the HUGE disadvantage that the PRC ported head is giving away by running 10 degrees less timing.

Besides isn't the small runner suppose to make huge low & mid range? What happened to that? The larger runner with no timing made TONS more low & mid range. Imagine what the graph would have looked if the PRC head had more than 18 degrees of timing! Claiming less than 1 point of compression made ALL of this difference just doesn't fly with anyone who's not a big AFR nut swinger.

I'm sure we'll have the typical but, but, but, it's AFR response, but at the end the bottom line is both heads are very good! Looks like this swap definately had its compromises. Give up low & mid range power because the damn Dart heads smoked That really sucks

SSilverSSurfer

iTrader: (8)

numbers still look good, i bet the car does bad ***

Orange Peel

iTrader: (20)

Thanks for the feedback fellas!!! Yeah the Dart 225's I had were eating about 1 to 2 quarts of oil a week, it was smoking and starting to run like *** with all the oil in the valves, etc.

Jason - Thanks again for helping me out with this Dart oil consumption issue, I'm VERY happy now that I have a car that doesn't eat oil and is running great. You guys are truely a stand up shop for helping us out with this. I liked the power the Darts made, they did a good job, it just sucked they had the oil issues, etc. The compression was a tad much for AZ, but I can get a bigger cam or something to get some more power and take the AFR's down a little with a mill if I ever feel the need. This car will be seeing a 200-300 shot on nitrous in the winter, so I don't think it's going to matter much then

Yeah the low end responsiveness is nice, the high velocity runner is doing a good job, and with the loss of the compression, it did lose some power, but I can't notice it It's nothing major, I can get some compression back later down the road and see what it does, but for now it's running EXTREMELY well, I can't stop laying the hammer down Even cruising on the freeway my speeds have gone up because it's sooo smooth and picks up speed so fast with the slight push of the throttle.

Nic did an AWESOME job of tuning this car, it's running great, he spent a lot of time on it and has seen it transform along the way. Thanks again buddy!!!

I'm really thinking of swapping the cam out later on, it's a little on the small side for this motor, and I'm sure I can pick up some good power with a slightly more aggressive LSA or something.

Tyler - Whenever you are ready to go for a ride I'm down, it's gonna be SWEET when you get your car back!!!!

Orange Peel

iTrader: (20)

Yeah the lower timing sucked to have, but it did make power, and I loved that! I don't know what I would have been able to run on the bottle, probably even less timing, but I don't know too much about tuning and nitrous together. I was very happy with the Darts, it just blew *** they smoked and ate oil. I had the cam built for those heads and setup, I don't know what I would gain from a new cam for this setup, but I'll find out someday.

The PRC port job seemed to work great, it may have been too much for this motor on the top end as it seemed to level off and not carry out as much as the AFR's did, but it made more low and mid range torque.

I'm by no means a nutswinger to any brand, I liked the Darts, they worked great, I like the AFR's because they work great also, they are a proven head with little issues that I know of, when the Dart issue gets taken care of they will be a great head, they can use a little more combustion chamber to lower the compression, but other than that they work.

I'm eager to see the Edlebrock head results, the more heads the better. But I'm happy with the results, the car is so powerful 1st through 3rd gear are pointless, fun as hell, but pointless Come winter it's gonna feel like I gained 20rwhp with the cold air!! But it still hauls *** in the 110 degree weather today

Jason 98 TA

iTrader: (4)

Glad you happy Scott! I wish we the Darts wouldn't have consumed so much oil. If we could have run adequate timing I think the peak would have looked a lot like the mid range did. Oh well.. In the end you still have a good running car that doesn't smoke! I promise you to get that port in the edlebrock & get it back on the market ASAP! Maybe I can even get you to try out our new 230cc stroker cylinder head we're working on.

Orange Peel

iTrader: (20)

Thanks dude! Let me know what you guys find out on my set if you would. Yeah I couldn't imagine the power the car would make with 28 degrees of timing, given the CR was in the right area. Hey, I'm down for trying anything out and seeing what it does, it's not very fun swapping heads, but it only took me a day on this one, I'm kind of getting good at it

eb02z06

iTrader: (18)

Nothing like 500 rwhp N/A-enjoy it bro!

Orange Peel

iTrader: (20)

Thanks! It's definitely a blast to drive! I need to stay out of it though, it's addicting haha!!

black_knight

iTrader: (1)

What's Ed got to say about how much power you're leaving on the table by not having your cam custom'd for your new heads? Worth the swap or no?