243s & LS6 vs FAST & 241s
Thread Starter
Joined: Apr 2005
Posts: 361
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From: Huntington, WV
243s & LS6 vs FAST & 241s If you couldonly do one or the other which would you choose. Get a set of stock 243/799s and a LS6 intake or leave your stock heads and go with a FAST 92/92 setup. The goal is street fun with retaining as much low end as possible. Car is M6 with a 4.10. Cam is most likely gonna be Tick SNS2 and just need to figure out the smartest way to finish off the project. Please dont make other more expensive suggestions or tell me to send my heads to AI because clearly I would if I could but its not in the budget right now. Thanks
I agree. Your LS6 intake will be fine with that cam and the stock 243 heads. Plus, the 243 heads are going to be cheaper than having to buy the FAST intake and TB.
OP, I have that cam and you are going to love it. Great power throughout the RPM band.
OP, I have that cam and you are going to love it. Great power throughout the RPM band.
It depends on price for your situation, the gains are going to be small with either choice as far as HP/$.
Some here might disagree, but I would never pull stock LS1 heads to replace them with them with stock 799/243s unless I was fixing something (ie lifters, head gaskets, etc). It's too labor and cost intensive for small gains (don't expect more than 15rwhp).
If you do the math be sure to include: price of heads, head gaskets, head bolts (you can't reuse stock), oil change, coolant change, and water pump gaskets at a minimum. I wouldn't install used aluminum heads that hadn't at least had a clean up pass on the surface to insure they aren't warped.
Some here might disagree, but I would never pull stock LS1 heads to replace them with them with stock 799/243s unless I was fixing something (ie lifters, head gaskets, etc). It's too labor and cost intensive for small gains (don't expect more than 15rwhp).
If you do the math be sure to include: price of heads, head gaskets, head bolts (you can't reuse stock), oil change, coolant change, and water pump gaskets at a minimum. I wouldn't install used aluminum heads that hadn't at least had a clean up pass on the surface to insure they aren't warped.
I'd do the FAST/LS1.
The difference, stock to stock, between the LS1 and LS6 is about 20cfm of flow via a larger port in the LS6. It's good for about 15-20HP. A FAST 102 is good for about the same vs the LS6.
You don't look at peak flow through the manifold, you look at how the heads/manifold work together. Mamo posted stuff years ago that showed how even though a FAST 90 would cap the CFM at 285 or so, if you kept putting better heads behind it, it kept making more power. Same holds true for the manifold - a better manifold means the heads can work better. And since we're talking stock to stock, the FAST/LS1 would not give up anything to the 243/LS6 combo in terms of overall flow or HP.
The difference is the FAST is more expensive than 243s, but you'd have an even better setup once you step up to better heads down the line.
The difference, stock to stock, between the LS1 and LS6 is about 20cfm of flow via a larger port in the LS6. It's good for about 15-20HP. A FAST 102 is good for about the same vs the LS6.
You don't look at peak flow through the manifold, you look at how the heads/manifold work together. Mamo posted stuff years ago that showed how even though a FAST 90 would cap the CFM at 285 or so, if you kept putting better heads behind it, it kept making more power. Same holds true for the manifold - a better manifold means the heads can work better. And since we're talking stock to stock, the FAST/LS1 would not give up anything to the 243/LS6 combo in terms of overall flow or HP.
The difference is the FAST is more expensive than 243s, but you'd have an even better setup once you step up to better heads down the line.
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Verdad Gallardo Ls6 intake is not a bad intake. Works well with 243 heads obviously you can achieve good numbers with either setup you go with. Swapping intakes is nothing. Swapping heads is a different story and is something you want to do only once.
At first my thought was the 243s & LS6 with the Tick SNS2 would likely be the better, more performance combo of the two by a very small margin. But I have to agree with JakeFusion on this one, he has a very good point IMO. The 241s & FAST 92 setup with the SNS2 cam is money better spent right now IF you're planning on better heads in the future. The 243s are approx. 20cfm over the 241s, not a whole lot. And it'll save you a head swap (re-surfacing heads, head gaskets, head bolts, etc) at the moment if the 241s are already on your existing motor. And of course either route requires a valvespring swap.
Intake swaps are much easier.
I wouldn't waste the time and effort to go from 241s to 243s stock to stock. Might as well save up a bit more and do a ported set of 243s and make the swap worth it (40+HP).
I wouldn't waste the time and effort to go from 241s to 243s stock to stock. Might as well save up a bit more and do a ported set of 243s and make the swap worth it (40+HP).
I found 799s for under $300 shipped (1 had some minor scarring from piston failure. I still didn't put them on until they were at least mildly ported and shaved.
How are the suspension and tires on the car? You might be better off dropping the money there than either the heads or intake.
Thread Starter
Joined: Apr 2005
Posts: 361
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From: Huntington, WV
I have er streets and gto spares for tires. My suspension is pretty much done also along with S60. I have spent the last few years doin that stuff first now I'm finally ready to add horsepower to it. The heads I'm looking at are new never bolted on is why the price.. no they are not sodium
TECH Addict
Joined: Apr 2009
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I gained 48rwhp / 21tq with ported 5.3's and a slowhawk tune. You wont ever see that much by swaping intakes however my heads are ported so its not a fair comparison 
I wouldnt waste the time and money on installing stock 243's. Thats leaving alot of power on the table.
I wouldnt waste the time and money on installing stock 243's. Thats leaving alot of power on the table. 
It's a wash power wise, but the heads will be more labor intensive to install. The added compression will allow for slightly better driving manners.
What you could do IMO that would beat out the Fast intake/241's with the 243's is have them milled for 50-75 bucks to 62.5cc, toss a .040" gasket on there and call it a day. It would drive better from the added compression and add power across the board. Not to mention tightening your quench up will also add power gains as well.
I think a lot of people underestimate compression and/or don't utilize it fully along with quench.
What you could do IMO that would beat out the Fast intake/241's with the 243's is have them milled for 50-75 bucks to 62.5cc, toss a .040" gasket on there and call it a day. It would drive better from the added compression and add power across the board. Not to mention tightening your quench up will also add power gains as well.
I think a lot of people underestimate compression and/or don't utilize it fully along with quench.
Yup. You can make up a lot for how a cam drives by throwing compression at it. Have a donkey dick cam that doesn't drive for ****?
More compression will help that sumbitch run!
More compression will help that sumbitch run!
Thread Starter
Joined: Apr 2005
Posts: 361
Likes: 0
From: Huntington, WV
Im also worried about the lifters situation. I cant imagine taking heads off replacing everything like lifters, head bolts, head gaskets etc and then bolting the same crap heads back on ugh... I think I am just gonna get some 243/799s and have them milled and call it a day. LS6 intake of course.
Martin, how hard are those new cams on lifters? My car has 96k on it and I feel like its basically a crap shoot not replacing them in the event of going cam only. Also, what do you reckon PTV will be like with your SNS 2 cam, 243s cut to 62cc, and a .040 gasket?
Thanks again guys
Martin, how hard are those new cams on lifters? My car has 96k on it and I feel like its basically a crap shoot not replacing them in the event of going cam only. Also, what do you reckon PTV will be like with your SNS 2 cam, 243s cut to 62cc, and a .040 gasket?
Thanks again guys
Im also worried about the lifters situation. I cant imagine taking heads off replacing everything like lifters, head bolts, head gaskets etc and then bolting the same crap heads back on ugh... I think I am just gonna get some 243/799s and have them milled and call it a day. LS6 intake of course.
Martin, how hard are those new cams on lifters? My car has 96k on it and I feel like its basically a crap shoot not replacing them in the event of going cam only. Also, what do you reckon PTV will be like with your SNS 2 cam, 243s cut to 62cc, and a .040 gasket?
Thanks again guys
Martin, how hard are those new cams on lifters? My car has 96k on it and I feel like its basically a crap shoot not replacing them in the event of going cam only. Also, what do you reckon PTV will be like with your SNS 2 cam, 243s cut to 62cc, and a .040 gasket?
Thanks again guys