docwyte

iTrader: (4)

Haha!

I'd LOVE to have a set of long tube headers on this car. However that isn't going to happen without a LOT of fabrication work. Since I don't have the time, and most importantly the skills to do that myself, that turns this into a very expensive proposition.

As such, I'd rather put in a different cam to try to make up the difference, knowing that I won't see as much power as you F body guys would. As long as I can hit my goal, I'm happy.

There have been some questions about my intake and perhaps I'm losing power there. Right now I have a straight shot intake going into the stock throttle body. However I have the air filter mounted directly to the MAF. Theory is that's creating turbulent air and causing the motor to lose power. Thoughts?

I don't have alot of room to move the MAF closer to the throttle body, I can move it maybe 4-5" and not have it on top of the throttle body. I do have a lot of room laterally, so I can fit a siamesed air filter arrangement or something. I think I saw something like that for corvette/f-bodies. Anyone know what I'm talking about?

disc0monkey

iTrader: (10)

thats weird the split is still small. im am interested to see what the reasoning is. i would think like a 222/230 would be more on the safe side to make sure the cylinder is getting cleared out, but what do i know.

just trying to learn.

docwyte

iTrader: (4)

Yeah, I thought so too and I asked him why. He felt less intake duration would make less power than I have now...

HAZ-Matt

iTrader: (8)

Which lobes is the cam that you have now ground on?

I don't really know how much of a real difference that would be. It would be neat to see an overlay of your 224 with the EPS 222 and 226 with it.

The extra exhaust duration should help you. I guess the real question is what the ratio of intake to exhaust flow is in your engine with the 241s and shorty headers. I guess I don't know any better and would imagine that you could make the extra 20HP with the 241s without going any bigger on the intake (or even slightly smaller), but increasing the exhaust.... especially considering the outputs of the 218/230's on stock manifolds (admittedly with 243 heads).

Should be interesting to see how it turns out though.

docwyte

iTrader: (4)

Not sure which lobes I have, I confirmed it's the Thunder Racing cam though. In talking with Geoff@EPS he thinks I can make the power I'm looking for with this cam. Nice thing is since I ordered my valve springs and push rods from Geoff he was able to check the specs and they'll work on my new cam, so no need to replace them.

I picked up a used K&N intake that I'm going to modify to fit my car. The filter is 3 times the size of the one I'm using now and it has a smooth transition between the filter and the MAF. Hopefully that will take care of the intake side.

If push comes to shove I can always install the CNC ported 243's I have...

180ls1

iTrader: (4)

milling you stock heads would help a good amount also if you want to save coin. What cats and mufflers are you using?

docwyte

iTrader: (4)

Yeah, but if I'm going through the trouble of pulling the heads off, I'll just install the CNC ported 243's. I already have them ready to go. Really it's the labor of job along with gaskets, head bolts etc that's putting me off...

HAZ-Matt

iTrader: (8)

Yeah they are proprietary Thunder Racing lobes, and are sort of in between Comp XE and XER.

Hopefully you won't go over 375RWHP with these changes

docwyte

iTrader: (4)

Having a little too much power I can deal with. I can run ballast or more fuel, or I can pull a little timing out to compensate.

If I make way more power than expected that may be a bit of an issue and I may have to figure out how to run a restrictor plate. I don't anticipate that being an issue with the headers I have now though...

00pooterSS

iTrader: (40)

Food for thought, those worked over 243's may put you exactly where you want to be in power output.

From what I gather you are wanting to go bigger on the cam to meet your goal, and then if you are over your power goal you can fatten the A/F or drop some timing, any of which, including installing a cam with more duration will adversely drop the responsiveness of the power delivery on the low end especially and also make it feel a bit lazy in comparison to a smaller cam, even though total output may be higher the actual function will lack. And if you are doing Auto X style racing you want hard hitting immediate power. So I recommend you do the best you can with you exh setup, even if you have shorties just make sure the piping after the shorties is optimized, then use a mild cam, good heads, lots of timing and compression and you should be golden.

Again I stress that if you over cam the car and have to go back and pull timing or fatten the mixture its going to kill the overall drivability and responsivenss of the power output. I believe you will be happiest if you plan your build around running the most compression and timing you can so that the power output is very spunky and quick to respond to throttle input. You then will also have the most efficient fuel burn and fuel efficiency to boot. Discuss those things as being your main goals with EPS and see what they can come up with for you.

I know you don't really want to swap heads based on your responses earlier but keep in mind that the most valuable and rewarding part of your engine build is in the heads and their ability to optimize your setup or adversely affect your setup.

edit: I have drank quite a bit so if any of that did not make sense that would be why lol

HAZ-Matt

iTrader: (8)

I think it made sense, but I agree and disagree.

I don't think the heads by themselves will give him 30-35RWHP in this situation. I think the main issue is getting the exhaust out and although his 243's might otherwise help the exhaust flow out through the head, they still have to get through the shorty headers.

I don't disagree necessarily with your thoughts about the 243's in conjunction with a different cam spec, including the later point about compression and the allusion to DCR... but the OP doesn't want to pull the heads and that is also understandable.

As far as the final power output, it could be "detuned" just in the RPM window that it is overpowered... or hopefully just a little extra ballast could be added or whatever. I don't think an extra 20 random horsepower is going to show up and make this a 400RWHP car on that dyno and cause a big headache. I was just a little surprised by the cam spec (which is why I made my comment). That was partly because it seems to me based on a lot of "ricer math" that I have done in my head for various setups that the various "stock manifold" grinds would have been at goal, or rather would have been there with a modest intake duration bump... but I am an enthusiast and am not claiming to be a professional.

Who knows how much of that is valid... I can't say I have any experience or had really thought about LS1's in 944's and the nuances of the intake or exhaust compromises that have to be made due to packaging until reading this thread. There is a 10HP cushion in between a 30-40HP gain so it isn't like anyone had to try to spec out a cam to make an exact horsepower target of 374.679RWHP. It should be interesting to see where this cam actually comes out.

00pooterSS

iTrader: (40)

And I agree with your agree/disagree and the comments you made following them.

I myself in this situation, since any path traveled will ultimately be hindered by the exhaust, I would solely focus on that first.. Yes I know it is costly but like I said earlier you are going to be happier if you fix the problem rather than band aid it. My suggestion is this: you could hunt down some used un coated headers and work with an exhaust shop and cut them up to make them work. I think that wouldn't cost all too much really.

disc0monkey

iTrader: (10)

i dont think his exhaust is a bandaid. it just is what it is. the OP said number of times its not worth the effort to time. you can taylor a cam to this, will you lose power sure, but he isn't too from meeting his max power restriction. i have done 370rwhp which is his max hp with a little more than just a cam but its a fully stock exhaust and intake.

docwyte

iTrader: (4)

Plan is to get the cam in along with the much larger k&n intake. The intake will also move the MAF away from the filter and hopefully take care of any turbulence in the intake.

If I don't make the anticipated power, then I'll either install the 243 heads or look into getting a set of long tube headers fitted to the car...

Darkman

iTrader: (2)

Good luck, and by all means report your results.

LargeOrangeFont

iTrader: (3)

I am kind of in a similar situation to you... I am trying to keep it under 400 WHP in my RX7 track car...

I ended up going with a GM ASA cam and stock port but slightly milled 241 heads for now. If I need more power I will swap the cam and put on some 243 heads.

If you make a bit too much power why not just make a small restrictor plate for the throttle body?

Marky522

iTrader: (8)

Hey Doc, sorry to see your still fighting this problem. Not that it helps you now, but i still plan on contacting S&P when im done with my headers to see if they are interested in setting them up like they did XSBoost's, but i doubt they will do it again when they already have a setup.

Here is a pic for everyone else of my home built headers to get around Doc's issue, because i am trying to get 400hp out of my 99 LS1 engine in the same platform, any suggestions of headers that may fit would be appreciated, but im pretty sure the options have been run dry as my headers would not fit on a engine with a stock oilpan, the filter would hit the header. And its hard to tell but the collectors kick to the center of the car where the primaries go into the collector.

And the header on the right has that hole in it to clear the steering shaft.





Here is my album to show fitment in the car
Album

docwyte

iTrader: (4)

Well, I'm not running a stock oil pan and I also have an oil filter relocation kit installed, so I'm ok there. I do need clearance against the pan where the oil lines come out and go to the filter relocation though.

EPS is making the cam, so I'm waiting for it to arrive. There's a chance it'll arrive before the holidays, but most likely it'll come early next year.

Thought I had an intake bought but the sale went through, so I'm still looking for a k&n fipk to fit to the car...

Marky522

iTrader: (8)

Yeah, i dont think most people can fit the stock oil pan due to the cross member, I was all set to get an f-body pan since i modified my corssmember but then realized I wouldnt have clearance for the filter, I was so excited not to have to run a remote filter. That was more for people to realize how hard it is to find off the shelf headers that will fit, you could post pics of the beautifully modified hooker headers... For the oil lines I am making a hard line that will run along the block and behind the motor mount where it will jump over into the wheel well to my filter, i didnt want to run them so close to the headers, this was the only way around it. I cant wait to finish them up, its just been to cold to be in the garage... I am following your build closley because i have the better flowing headers but only a LS6 cam so we should be in the same area power wise.... I just want to make it run....




Mark

docwyte

iTrader: (4)

I like having the remote filter, makes doing oil changes so much easier.

I think the only way you can run a stock oil pan is if you get TPC's custom cross member. Even then I'm not sure if you can keep the oil filter in the stock location though...