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Dyno results with just ported heads

14K views 14 replies 8 participants last post by  Goats Eat Everything 
#1 ·
Ive search the web alot to find out how true ported heads will effect and improve hp on our engines. Found more ls3 forums and camaros with this info but alot to most of these forum posts were not just heads. Mostly head/cam combos.

My car is currently cai, pacesetters 1 3/4 longtube, xpipe, doug thorley axle backs, cammed, and 3600 yank ss stall. Pat g tuned and cam specs are 219/227, 604/614 @ 113+1.

My next upgrade was heads at this point, so i bought a set from tsp. These are the $1300 stock casting prc heads. They are cnc ported, stock gm valves, .660 springs, milled .035 also. Gaskets and pushrods and misc items came out to about $1800.

The car is currently being worked on by a well known reputable shop in michigan as i type this.

Base dyno was 404/425.

Now the only thing that will be different are the heads and a dyno thats 3 days later. So we will see how these budget heads from prc will perform.

Ill let everyone know as soon as i find out later today.
 
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#2 ·
You will be gaining hp from both porting and the compression increase with milling it will be impossible to know how much you gained from each factor.
 
#3 ·
Yeah i realize that, but it will give a close idea. And most are milling there heads anyways when they buy through tsp. They mill to the cam.
 
#4 ·
results are in, with a little tweaking to the tune, and my installer told me that the dyno torque munbers are a little skewed from the stall converter, it made:

427 hp and 475 tq.

old numbers 3 days ago without heads were 404/425.

so thats a gain of 23 whp for ported/polish/milled heads on a small to mild cam.

Im happy with these results, my best ET was a 12.09 @ 113, so this should easily get me into the 11s. Was it worth the cash? well...its alot to spend on a 23 hp gain. so gain vs $$ = too much money, but thats why we mod are cars in the first place.

hopefully this comparison will help anyone in the near future whos thinking about a head swap.
 
#5 ·
I think the more important number there is the tq...thats a huge gain, one that you can feel. And judging from the numbers most of it was down low that you gained it, great for the street.
 
#6 ·
Yes thats a huge jump in tq, which kinda makes me skeptical on how true that number really is. The shop said they run the converters locked so your gonna see a bump in tq, and says also there dyno tends to be a little stingy with power. 10-15 hp over a mustang. Cant wait to drive it!
 
#7 ·
You should run the track and see how much better it is in your time vs before. For my automotive degree, we dynoed vehicles then porting heads and redynoed for this class exercise. That was the only change to the vehicle and it was only micro horse gains. So not worth it from what I saw. But you also had more than just that done so maybe all together it can contribute a lot. Still the true test would be the track time.
 
#9 ·
Yes, with just the stock heads on. No port, polish or milling.

Just to give a little info on my car on previous dynos, vms did my cam/dod delete install, they dyno-ed my car on there mustang and it made 370/345 (without stall and 102 maf). A year later went to alternative performance dyno day, same mods, just a dynojet instead and it made 395/375. Then the last dyno was done up above at this shop.



I will be taking it to the track this year of course to see the difference. We still have some snow days here in michigan :/

I would like to maybe run a 11.8 @116. I would be happy with that.
 
#11 ·
Thanks!
 
#13 ·
So i know this thread is old but i finally got to the track yesterday to get some updaed times with the new heads.

Just a recap, befor the heads i was making 404/425. Thats with a mild cam (specs above), pacesetter long tubes, doug thorley axle backs, cai, pat g tun, 3600 stall with hoosier 275/45/17.

My best time at the track was 12.09 @113 with a 1.73 60ft. With alot of 12.1 - 12.2s times.

Now with the heads i made 427/475 and went to the track with new times of...........

11.71@116 with a 1.65 60ft. I was consistant yesterday with a bunch of 11.8s with a worst 60ft (1.75ish) and 2 11.7x times.

So over all with the whole port head experience im very happy with my results and feel the car os running strong ! I think a 75 shot is in my future.!

Hope this post helps anyone looking to use or buy these prc heads from texaspeed. Deff perform well.
 
#15 ·
Very nice pickup all across the board especially your ET/trap. Any idea how the weather compared between your two track outings? DA?
 
#14 ·
Thank you posting the results
 
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