Joes98Blackbird

I have a 98 Trans am/Stalled3k-A4 and I was wondering about doing heads now. I have a mild cam/lS6 intake and it makes a respectable 345rwhp with bad knock sensors/stock fuel pump "UNTUNED" at the time and since then, i have upgraded the fuel pump and changed the knock sensors and harness. I want heads now and these 806's ain't cutting it. I want 243's/ ported if possible but those Staged 2.5/5.3 liters heads are nice but i don't want a very high compression though. I would like to have some insight on this matter and i would like to know what hp gains I would see. Thank you! Go fast or go home!!!!!!

HCI2000SS

iTrader: (2)

I am running stage 2.5/5.3 heads and for the money i'm very happy. The compression bump isn't much at all. I believe stock is around 10:1 and i'm around 10:8 with these heads

Joes98Blackbird

How much power if you don't mind me asking are you making? I know the A4 make less power vs a manual but i wanna get an ideal of how much "that" i could be making. I have a partner with a closer set up towards yours and he made 441rwhp but he did had a fast90/90TB and then got the car retuned and made 462rwhp wow...... I'm trying to make 400 to 415rwhp...

adamantium

iTrader: (3)

^Dyno #'s are irrelevant.

From the videos ive seen HCI2000ss's car is definitely a strong runner!

HCI2000SS

iTrader: (2)

Thanks man, and I agree 100% on the dyno thing!

OP let me give you my car as an example: My car has been on 2 different dynos (both were Dynojets as well) and it made 405 rwhp on one, and 460 rwhp on the other other. See my point lol Regardless, the car runs strong for what it is, and I have ran with cars making quite a bit more hp than me. Obviously there are better heads out there, but for the money these 5.3 heads are hard to beat IMO

BrntWS6

iTrader: (7)

Dyno's aren't irrelevant if you get a baseline on the same dyno. Before I made 341 rwhp with bolt-ons...basically a lid, ported TB and full exhaust. After 2.5 ls6 heads, Torquer V3, FAST 92/92, UD pulley I made 461 rwhp on the same dyno at 10.6 compression. So with that combo I gained 120 rwhp and 56 rwtq. I also got a new exhaust by switching to TD's to compliment the new setup.

adamantium

iTrader: (3)

That has nothing to do with whether the car performs well or not.

john563

iTrader: (17)

i have those heads ands in an A4..ran 7.15 or 7.16 in the 8th..car put down 435rwp then replaced 1 3/4 headers with 1 7/8 headers and a 4insh ypipe with a 4inch flowmasters merge..so its around 440 rwhp if dyon numbers is your thing..

honestly im very happy with the heads i have no complaints

adamantium

iTrader: (3)

I think you should worry about your MPH gains, not ET. MPH tells the tale. I just actually installed that setup, its loud as **** but i do feel a noticeable difference low end and mid range on the butt dyno

Do you know the MPH gains? If there were any?





Also when i say dyno numbers are irrelevant, i mean in the sense that it doesn't actually tell you how fast your car is. Its a tuning tool, thats all. Its a great way to tell wether the mods or tuning you did paid off, but doesn't necessarily tell you how fast your car is. Thats what i was attempting to say when i said they are "irrelevant".

HCI2000SS

iTrader: (2)

I remember when I had my Mustang and had a canned tune (had it dynoed) then had a custom dyno tune (had it dynoed on the same dyno) and they were within 2 hp of each other, but guess what??? The car was noticeably faster with the custom tune, and would consistently trap 2 mph better at the track.

BrntWS6

iTrader: (7)

Sure it does....it performes 120hp better that it did before my H/C. He was asking about dyno numbers....I answered his question.

badazz81z28

iTrader: (6)

That's basically what I did. I ran the track for MPH. Driver's can make ETs all over the place. I ran at the track and was as high as 15 sec and as low as 12 seconds, but MPH was consistent.

Dyno runs are great for tuning, but I never take the numbers posted on this site as gospel. People inflate, dynos inflate and some dynos are conservative.

badazz81z28

iTrader: (6)

I would go with the 243 heads. If you buy the PRC heads, you can have Texas Speed mill them for your desired compression. If you want low compression 243s would be better.

reeperz28

iTrader: (1)

Do this for me use the search on this forum and search in the dyno section prc 2.5 243' s and then search prc stage 2.5 5.3 heads. I have personally seen an overall average better number from the prc 5.3 heads with many different cams. n/a that is.

badazz81z28

iTrader: (6)

I don't have to. Texas Speed has already tested the two cylinder heads in exact configurations. The LS6 heads make more power.

Like I mentioned before, I don't trust the dyno section. Too many variables with set-ups, conditions, dynos etc..I have seen cam only cars post higher #s with 241s. That doesn't mean we should forgo the heads and just do a cam.

badazz81z28

iTrader: (6)

PRC LS6 450RWHP...https://ls1tech.com/forums/dynamomet...-450-rwhp.html

Basically the same combo, only 428RWHP https://ls1tech.com/forums/dynamomet...ls6-heads.html

5.3 heads with same 228R cam 416RWHP https://ls1tech.com/forums/dynamomet...o-results.html

5.3 with 224R 404RWHP https://ls1tech.com/forums/dynamomet...-2-5-5-3s.html

I also saw a 5.3 head combo with a little bigger cam that made 450 RWHP

Too many variables in the Dyno section. I will trust Texas Speed on that the LS6 heads make more power.

adamantium

iTrader: (3)

Comparing dyno numbers from different dyno's, correction factors, states, weather, and parts list is dumb and irrelevant. If you want to contribute show a back to back dyno on the same car and same day.

Joes98Blackbird

Thanks guys for all of your opinions and statements. I really appreciate that very much. I want 243's but then i want them ported and and new everything. I have a buddy of mines that have a set of used 243's but then they are NOT PORTED!!!. I have seen what both 243's and what the stage 2.5/5.3 can do so i might just buy the Texas speed heads and call it a day, at least they comes with everything and all i got to do is bolt them on and go. I wanna do this 'heads thing' one time and this going to be my daily driver. I can't wait to get these heads!!!

john563

iTrader: (17)

ill have to find my slip to see what mph was..as far as dynos being irrelevant,well i know its a tuning tune been around awhile ...just trying to give the op an idea is all

reeperz28

iTrader: (1)

By the way your 450 vette dyno there seems a little fishy with 444 tQ on 346cubes


Good point with the 228 cam no doubt the 5.3 heads love a bigger cam.
https://ls1tech.com/forums/dynamomet...0-results.html
https://ls1tech.com/forums/dynamomet...ph-inside.html
https://ls1tech.com/forums/dynamomet...0-results.html
https://ls1tech.com/forums/dynamomet...-pump-gas.html
But my opinion on the op's original question cant go wrong with ported 243's from t.e.a or AI or livernois.