LS325ci

iTrader: (3)

I was reading up some more on heads and people agree that the 806 is the least flowing heads. but how much power does it actually rob vs 241?

That I cant seem to find. most people that change the 806 upgrade a lot more.

which brings me to my next question with full bolt on of fast intake /tb with true dual, LT etc will it be possible to get 400 whp with a smallish 224r cam? or do you need bigger cam to reach that goal through an a4?


also side question with tuning if you change the stall to higher one will that affect tuning? (i think the answer is no but just curious.)
how about gears?

im curious if I should get tuned after bolt on and cams or wait to install cams/gear and stall and tune all at once.

RPM WS6

iTrader: (3)

Who agrees that 806s are the "least flowing"? What evidence do they have to support that the 853s are any better in this regard? Only difference from 806 to 853 is the valve covers/coil mounting, IMO.

241 used a slightly better casting process, but this won't translate into big power differecnes, any amount would be small.

806/853/241 are all the same once ported, so if you plan to rework stock LS1 castings, no need to change unless you want the different coil mounting system.

Hitting 400rwhp with an A4 would be tough with only a 224 cam and stock heads. Someone may have done this though.

HCI2000SS

iTrader: (2)

Number will depend on the dyno. I've learned that one lol

LS325ci

iTrader: (3)

thats what people are saying. but what is "small" gains?

https://ls1tech.com/forums/generatio...241-heads.html
https://ls1tech.com/forums/generatio...241-heads.html

just two example of people claiming that gains may be minimal that youll never notice. BUT my question is for the cam only cars whats the hp difference? curious as to why 241 is cheap but 806 are for 50 bucks cheap lol


im looking to set up a car that makes 400whp/torque cam only. what would you recommend?

looking for more down low power since its a dd and would prefer bigger powerband vs peak. goal is just a generic route.


im thinking 1 7/8 LT 3" true dual x pipe and exit after axle.
slp lid, ws6 ram, stock tb fast 92/92.

what cam will maximize this setup? I dont mind shifting at 6400 or so.
without sacrificing my drivability/idle. i do need a/c and rather not put on a a really aggressive cam idle.

HCI2000SS

iTrader: (2)

May I ask why you are so focused on a certain dyno number. There are several proven setups that will perform well regardless of what any given dyno says on any given day

LS325ci

iTrader: (3)

Because perform well is generic. It's like saying fast. It's relative to whose driving. I know for me I like 400-500whp. So i try to aim around that number

Proven set up? Aside from cams and heads not too sure how bolt on can vary much. Under assumption of similar maximizing set up.

dsadsdaiouser

We have 241 heads on our C5 and with a Pure Stock legal Stock Eliminator camshaft (stock OEM duration and lift - smaller than a baby cam) we make 382 rwhp. 1 & 7/8" LTs, UD pulley, Yank SS4000 and 3.90 gear. I don't know the difference between 241 and 806 heads but if you look on Advanced Induction's web site they fall under the same "category" for port work. I would think it's a comparable head. I would say yes, you could make 400 rwhp with those heads and a cam and could even do it with an LS6 intake (what we run.)

For a cam I'd call Martin @ Tick, BTR, or someone like that for a recommendation. I do believe it can be done and they (along with others) can steer you in the right direction.

Regarding tuning needed for a gear and/or TC the answer is yes. You'll need to get a tune to have shift points adjusted.

Scott

RPM WS6

iTrader: (3)

Those threads are 806 vs. 241. There is a 3rd LS1 head (actually a 4th if you count the '97 C5 head, but we'll keep this to the F-body years) which is an 853 casting. 806 and 853 are the same other than the valve cover style. I was just saying that it's misleading to state that 806s are the "least" flowing head (inferring that 853 is somehow better, which it isn't) since 2 of the 3 are identical in all ways but the valve covers. 241s did receive a slightly better casting process than 806/853, which is what that second link above was referring to, but I don't think anyone can give you an exact power number that this translates into.

All three of these heads (806/853/241) are identical in terms of performance potential, and there is no advantage to one over the other in this regard when it comes to porting, etc.

806s are the least desirable only because you must have the correct '98 style value covers and coil mounts to make them work. If you already have this stuff, then there is no disadvantage at all to getting these heads worked rather than getting 853s or 241s to be worked.

As mentioned in that link, I'd go to at least a 243 if I was going to the trouble of changing castings and didn't want to go aftermarket. No point in ever buying 241s just to get them ported if you already have 806s (with proper hardware) that you could port instead.


With an A4 you can use increased stall speed to "simulate" more down-low power by simply skipping past the low end of the rpm range. Throttle response can be instant with a well matched stall (and higher [numeric] gear ratio to reduce feelings of "looseness"), but MPG will suffer around town. Highway mileage will not be affected by stall speed so long as the lock-up feature works, and you can have it tuned to lock up sooner if you so desire.

I think something bigger than 224 would be needed for a guaranteed 400rwhp with an A4 and stock (unported) heads. Are you saying that you don't want to touch the heads at all, or just that you want to stick with stock castings but would plan to get them worked? Ported stock heads + 224ish cam (plus the other items on your list) could certainly get you to your goal and beyond. There is a point of diminishing returns when it comes to cam size and 100% stock heads. The slight improvement in the casting process of the 241s isn't going to be enough to really impact that point of diminishing returns.

You mention idle quality and driveability......with these as concerns, I'd want to limit cam size and focus more on reaching your power goals via head improvements, either by working the stock castings or moving up to a 243, etc. Yes, you can keep bumping cam size to reach better peak numbers, but you also mentioned wanting good overall power and performance. Thing here is that you don't want to get hung up on peak numbers but rather average power across your useable rpm range. I'd worry less about reaching some magic number and more about how well the setup works and behaves. 400+ rwhp with stock heads is nice, but I'd rather have a smaller cam, less stall speed, and better pull at lower rpm with improved idle quality on a street car.

Have you considered sticking with a 224-228 range cam while going with some ported heads? That would drive much nicer and probably make as much or more peak power (plus more average power) than stock heads with a monster cam.

LS325ci

iTrader: (3)

what I wanted originally is 224r cams with 243 heads.

But Im trying to avoid opening the engine at this point to do the heads.(wont have enought in the budget)
So I wanted to see if I can make the numbers with just cams and 806 heads.

Im deffinitely more interested in wider powerband vs peak. but people tend to ask for what my goals are so I stick them in there for a general guide.

what set up do you recomend that produce the best power curve using stock heads?

Fry_

A little over a week ago you wanted to stay California emissions legal now you want LT's, TD's, and a cam that can get you to 400rwhp cam only. I think it's time to stop and actualy figure out what you want.

7GRANDGERNADE

I believe its going to take a fairly Large cam along with a great tunner to get you to 400 with an auto on stock ls1 heads

LS325ci

iTrader: (3)

I did but after considering everyones response on what parts i would need and such. I made a parts list and $ count, I came to the conclusion that it would cost way too much to stay under the radar. it seems it would cost me about 1.5 times more for less performance...
so i changed my original plan.

RPM WS6

iTrader: (3)

Whether the heads are stock or not, a 224-228ish range cam is going to have very nice street manners (post-tuning) while still offering considerable gains over stock starting at reasonable rpms. I don't really have a recommendation beyond this because, if it were mine, I'd just wait until the budget allowed for head work rather than try to attain higher peak numbers with a bigger cam and stock heads. You could always do the cam now and then do heads later on for an additional gain, but that's a more expensive way to do it overall.

Lots of people have done bigger cams with stock heads, whether or not this is preferable is subject to opinion and goals. Personally, for a street car, I will always be a proponent of "smaller cam, better heads" vs. "bigger cam, lesser heads" to reach a given power range.

Now above it was mentioned that you have CA emissions concerns. I have no recommendation to offer in this regard, as we don't have a sniffer here (scan only) so anything and everything can pass in my area. If you have to pass a sniffer, then it's best to get recommendations from other CA people who have done this. Having said that, a smaller cam is definitely going to have a better chance of passing than something larger, so again you might need to wait until head work is affordable to reach your goals while still hoping to pass a sniff test.

MikeWS6

My car gained 48rwhp when I changed out the 806 heads for prc 2.5 5.3 heads. So they really cant flow that great lol.

Once you port them power is prob on par with 853/241 ect.

RPM WS6

iTrader: (3)

Were the 806 heads still stock, or had they been worked/ported/modified comparably to the 5.3L stage 2.5 heads? If not, this is apples to oranges and only confirms that ported heads are better than un-ported heads. You would have seen the same gain if you had started with 853s rather than 806s.

All of them will be on par with each other once all are ported. There is no difference between 853s and 806s other than valve cover arrangement, which obviously has nothing to do with power. And the only advantage to a 241 head is the slightly better stock casting process, which is marginal at best and is entirely negated once we're talking about porting castings, whether they are 806, 853 or 241.

MikeWS6

Yup stock 806's.
Agreed.