What do you guy's think of me going with stage 1 PRC heads?

With my new trans going in real soon with some 3.69's I'm looking to add even more top end.

I'll be contacting http://texas-speed.com/shop/item.asp?itemid=649 real soon unless I can find a better head.
I have read that these heads can add up to 50 whp. I'm thinking 25-30 across the band with my baby cam 5.3.

 

I would go with the stage 2 heads, better flow for a little more money, especially with all the supporting mods you have in your car now.

 

Stage 2 def! will accomidate FI in the future as well! LOL if that's still on the table...you'll give up on NA...LOL its already been determined! LMAO

 

got your pm ross.. ill hook you up later bro, when i get too my computer

 

What about these David?
http://www.texas-speed.com/shop/item...id=84&catid=40
They also have a smaller combustion chamber 58cc I think. It would put compression at 10.75

 

Well after doing a little research and talking to my cam guy I've found another great option.
http://www.advancedinduction.com/AiProductsGMLS2.html

https://ls1tech.com/forums/dynamomet...nths-5mph.html

I'm alrady at 10.25 Compression and most gaines are with a .030 mill which gives .5-.75 more compression depending on head gaskets used.
Intake Port volume will increase about 15cc and flow 40 cfm while maintaining port velocity. Gains under the curve should be expected along with much more top end. I'll gues 25-30 peak HP.

I'm also planing on going with the TPiS 90mm LS6 intake. I'll send mine in since it's been ported and modded for the LS4. They cut the intake neck off and plastic weld a LS2 90mm TB inlet to it. http://tpis.com/parts/view/39 Price is 350 if I provide my intake.
TPiS claims that With a bigger opening and an excellent manifold design, you'll make more power everywhere in the RPM range with no torque loss when compared to a factory intake.
Typical LS gains are 15-20 peak horse power and 10-15 lb-ft.
Going this route, I'll have to go with a LS2 throttle body and MAF. My header crossover tube will get re worked for extra clearance.
Here is some more info on the intake https://ls1tech.com/forums/generatio...take-pics.html

Shooting for 120mph traps and I'm not worried about losing a little bottom end since I have 3.69's comming my way. Besides the motor never falls below 4500 after each shift now so I'm looking for more power up top.

 

How are you going to get the ls2 TB to work? Your going to have to change the TAC module and the pedal.

 

TAC is built into our ECM. There have been a few who have done the TB and LS2 intake swaps on our cars. LS2 uses a 5 wire TB and we just have to combine the two grounds and do a little tuning.
Older DBW tbs used TAC modules.

From JDMC5
I thought I'd add this little bit of info I got a while back. It's an email from a guy who swapped an LS4, with an LS2 intake and throttle body, into his fiero. The first paragraph is me asking questions and the second is his response.

"I'd like to learn more about your LS4 swap. More specifically the LS2 intake mod. I read your web page where you covered most of the swap. From the looks of it you used an LS2 intake, TB, the valley tray and the fuel rail. I have a couple questions regarding this swap. How did you get the LS2 TB to work with the LS4 connector? What else did you do to complete the LS2 intake/ TB swap? I'm sure there is something regarding the OPSU and MAP sensor. Any help is greatly appreciated."

"The LS2 intake and throttle body are unmodified. The lifter valley cover is modified in two areas. It has a crankcase vent line that is cut off flush and welded shut. Also, the OPSU boss was cut off and a new one made from aluminum rod welded on at an angle to clear the TB. The LS4 MAP sensor fits the LS2 intake. I replaced the TB connector with one from an LS2, there are two wires un-used. The LS4 has two separate sets of 5v ref and ground circuits, on the LS2 they are combined. The LS4 injectors are too short, you must use LS2 type injectors. The car has not been fully tuned yet, but I started by importing the LS2 injector flow rates and ETC settings to get it running."

 

Ok so I'm looking at the flow numbers between the two heads and there doesn't seem to be much difference. Other than the fact that the PRC head out flows the other by 12 CFM at .600 lift on the intake. Also it seems the PRC kills the other head on the exhaust side. The other thing I noticed is cost. The PRC is $1235 with .650 max lift springs and titanium retainers and stainless steel valves. The other head is $1995 and that does not include the stainless steel valves.

 

Dave, I'd actually say you have a middling cam, not a baby cam. But that's just me.

I really like the Advanced Induction heads. They just went into my master list of performance part options. The PRC heads have an E/I ratio of about 0.7, and the AI heads come in around 0.85. I would take 0.85 over 0.7 in a heartbeat. Even though you are giving up some flow at max lift, you are gaining flow everywhere else with the AI heads. You should probably see what Pat G. says, but I'd also recommend looking at an adjustable timing set. I think you'll want to pull the advance out of your cam with 3.69's, higher exhaust port flow, and our big header primaries.

 

AI heads it is. I've heard that the guy who owns the shop designed the LS1 ports for GM. Rummor?
Shooting for 10.5:1 CR and I'm at 10.25 now. We only milled .015" off of the heads. I'm looking forward to the new intake. SVO green top injectors with tuning and trans then I'm done so I'll be leaving the cam timing alone. I'm planing on retro fitting a LS motor into a foxbody Mustang at this time. If this doesn't pan out then I'll buy a Solstice GXP in next year or so..
Keeping the Prix till I die or it dies lol

Did you see the 111.33 traps?

 

I have now. Really nice... 120 mph traps would be nicer though! Lol, it's addictive. You're already a set of slicks away from 12s, but I'd love to see what you run on street tires after you are done. I literally have too many half-done projects scattered among all of my interests to check in as regularly, but I have been seeking out your posts.

What year Mustang? If you are going for a drag car, they are cheap and light. I'm partial to the Solstice though. They are beautiful cars. The base didn't have enough power for me, but the GXP was pretty fun. Plus, that turbo DI Ecotec is ripe for mods.

 

Mid 80's to early 90's 4cyl notch. Street/strip car with a 5.3 6spd 8.8 and 3.73's. Manual rack, brakes, windows, lock's, and no A/C.

Motor
224/224 .600/.600 112-114 L/S
CNC ported 243 heads 11:1 CR most 5.3s are 9.5 so I'd end up with 10.5 with a .021 mill. I'll have to explore unless I swap out the pistons. (LS4 pistons!)
LS6 intake
BRP 1 7/8" headers x-pipe into dual 2.5"
Electric water pump
Under drive balancer
ARP rod bolts/head studs
LS2 chain and tensioner
LS7 lifters
GM gaskets
LS6 std vol ported oil pump

Looked at 3 already just gatta finish my trans first.

 

Alright guy's I have finally figured this head build out lol

I'm going to go with the TFS 205cc heads. The small ports build super velocity.
In/Ex CFM over stock LS6 heads In/Ex.
.100 66/52 +4/+5
.200 135/109 +9/+1
.300 203/165 +19/+2
.400 257/209 +33/+46
.500 287/222 +36/+46
.600 299/237 +42/+54

With the 58cc combustion chambers vs 64cc (I'm about 62cc with mill) and stock .051" GM MLS head gaskets, my new static compression ratio will be 10.8:1 Vs. 10.25:1. Dynamic compression will be around 8.6. wich is about as high as one should go with pump gas. The improved combustion chamber design is supposed to allow better flame travel with less detonation.

The heads will require 7.5" pushrods and a after market roller rockers.

The titainum retainers and light weight valves will really help with the 6000rpm+ valvetrain stability. Stock valves weigh 101g's intake and 94'gs exhaust. The TFS (Manely valves) weigh in at 95g's intake and 88'gs exhaust.
Just for the record the 2002 LS6 243 head valves weigh in at 73g's intake GM P/N 12565311 discontinued and the exhaust valves weigh 65g's GM P/N 12565312

I have been a fan of these heads for a long... long time, so now it's time to try them out.

Our engine use's the truck 4.8 flat top pistons P/N 125017577. Typical 5.3's use a dish piston so GM was nice enough to give us a little extra compression with our 243's!


I was reading up on a few engine dyno tests with these heads and here is what I found that is close to my build

Iron 5.3
4.8 pistons
220/224 112 cam
Shorty 1.75"x3" truck headers
electric water pump/no accessories
TFS 205cc heads
LS2 intake and Throttle body
LS2 injectors

491hp@6300rpm 444lb-ft@4400rpm

I have a little less cam but more lift .595/.601 vs .575/.575
I'll be using the ported LS6 with the TPiS 90mm intake inlet and LS2 TB

I might retard my cam 2 degrees since it was installed advanced +degrees.

Ported 243's are a little over kill on this engine. Most 243's after CNC porting end up around 227-236cc's. They flow outstanding numbers but with bigger ports and valves. These heads would be better suited on a 5.7/6.0 with bigger cams.

 

So stock heads being ported are a waste of money???

 

They'd make power but at higher RPM's due to lower port velocity. This has been argue'd a billon times on this site. For a street car that has to power thru different gears, small is generally better. Stock LS1 heads are around 205cc. 243 are 211cc and are no joke! They flow very well and when ported, provide up to 5 tenths and 5mph in the 1/4. The CNC heads are better left to bigger bore motors. I really don't wanna spin this motor past 6600rpm. Rod bolts are little iffy past 6500.

The TFS heads were spec'd to out perform the 243's on smaller bore motors such as the 4.8/5.3's.

Definitely not a waste of money.. But for the street I'll stick with the smaller Intake runner head.

 

Thats good to know,if i stab a cam in this tramp.Are you staying with the pac springs and Hi-Tech 7.450" molly pushrods with the new heads?

 

I'll have to step up to a 7.5" push rod and I'll sell the TFS sprrings and keep my expesive PAC springs

 

LOL right on

 

.....I'll be disappointed if you don't run 11.0:1 compression.