Pray

iTrader: (7)

Well I had my TSP 2.5 LS6's flowed the other day. I set them up the same way I flowed my AFR 205's for an apples to apples comparison. First let me say that this bench is a little stingy but it is a good comparison. The AFR heads cc'd at 205 like advertised but the PRC's came in at 240cc. Both heads have 59cc combustion chambers.

AFR 205's no pipe, radius inlet
int.------------exh.
.100---76.7---.100---69.5
.200--146-----.200--120
.300--203.5---.300--161
.400--252-----.400--194
.500--288-----.500--224
.600--304-----.600--227

PRC 2.5 LS6's 240cc no pipe, radius inlet
int.------------exh.
.100---73-----.100---66
.200--135-----.200--116
.300--194-----.300--154
.400--247-----.400--186
.500--283-----.500--205
.600--304-----.600--214

As you can see the PRC's are down about ten every where except on the intake above .500" with a 35cc larger runner. I didn't cc the exhaust's. Now I can see why my motor didn't make the tq I was expecting. It still made 490/445rw but it looks like I would have been alot better off staying with my 205's. I am in no way bashing TSP but the numbers are what they are.

pdd

iTrader: (3)

nice comparo

ThirdGenLS1

iTrader: (11)

very nice comparision, shows that the PRC heads are a decent head for what they are. I mean i would never put them in the same group as a afr head, but for more then a grand less you can't really knock there performance. They are the "bang for the buck" head and at that they do a very good job.

TXZ28LS1

iTrader: (5)

agreed. the PRC heads are good performing heads for the buck which was the goal the whole time behind them from TSP. glad to finally see some actual #'s for the AFR 205!

Prerun4fun13

iTrader: (6)

Just goes to show you that stock casting heads are very good. For sure a good bang for the buck head.

davered00ss

iTrader: (4)

Why the F would you go from AFR's to PRC heads? Makes no sence at all. What were your #'s with the AFR's compared to the PRC's. How did the car feel driving it?

Pray

iTrader: (7)

Thanks guys. I try to put out pure facts with flow numbers, dyno numbers, and track times to back them up.

The PRC's are great heads for the money. I ran 10.8's@130 on motor with them so they can't be that bad.

Davered00ss. Calm down bro. You don't need to swear at me. I sold the 205's to a friend to get some ported AFR small bore 225's that turned out to be a total nightmare for my combo in the end. I spent an extra $700 on them to get them right and they still never worked out for my combo. So I sold them and only had enough money from the sale to get a budget head. I figured the PRC's were the best head in my budget range and I was correct. But I was a little dissapointed in the flow nubmers. Now when I had the AFR's with an LS6 intake and supermaxx headers, I trapped almost 128 on street tires with a 239/244 .651/.612 112+2 cam. The original dyno numbers were 464/445rw for the AFR combo with 500 miles on the motor. With the PRC's, 90/90, LG Pro's, 244/248 .612/.615 114+4 cam, 480/435rw I ran 130 best but an average of 128 on ET streets. With a better tune I got 490/445rw with alot more in the mid range but never went back to the track. The car felt vicious but a little weak on the bottom. I had to add alot of throttle cracker and timing to the bottom to get it to feelt the way I wanted. I put the smaller cam back in and got all my low end back with out sacrificing top end. I had to add some fuel to the low and mid range VE but didn't need to lean the top out at all. I was still pulling 600cc street bikes by three cars or so from a roll.

BayAreaSS

iTrader: (10)

This comparison shows me that the prc is a good budget head. Thanks for sharing

LS1C5Vette

iTrader: (11)

Wonder if the stg 2.5 5.3L heads flow as good as the LS6's?