RPM/HP upgrade question

[rrrcustom]

I have a '95 Mustang GT that I bought used back in October '08. The car was a well maintained, one owner (woman) driver, 5 speed 5.0L. Having said that it does have 175K miles on the original drivetrain.

I'm looking to get this thing to make a little more (OK, a decent amount, over 20 HP at least)power without having to rebuild the engine. It seems to pull OK, and doesn't use too much oil, so I think it's mechanically sound, just a little tired. I know a rebuild is in order but I'm not ready to go there yet. I'd like some sort of upgrade that will boost power, and RPM range of the engine. I'm no stranger to Mustangs, I have an '89 5.0 that is modified with GT40 heads, cam, intake, that runs like a top and makes awesom torque, but it too runs out of steam at 4800 rpm (according to the dyno). This is the one thing that has always irritated me with the 5.0's. I've also owned LT1 and LS1 Z28's, as well as a latemodel GTO, and these engines pull all the way to 6000 rpm. Even the 96-98 non-PI 4.6's pull higher than the 5.0.

Basically what I want to know is: if I only install one upgrade to increase RPM and HP, which one will do the best job? I'm trying to decide between a cam, an intake, or cylinder heads. I know the intake is a huge problem because of the long runners, but will it matter if the cam is too small? Are the cylinder heads the big bottleneck as far as RPM goes? I know they ultimately dictate total power, but would they keep engine power at a lower RPM due to flow restrictions at the higher lifts? Is the camshaft the main decider of the powerband of the engine, i.e. if a cam only has .444 lift will it always cause the engine to peak between 4000-5000, a cam with over .500 will cause the peak to be in the 5000 RPM range, etc..

My ideal combination would be a 331 stroker with an Edelbrock RPM or Trick Flow intake, AFR 185 heads (maybe 165's if they would still make the HP peak somewhere around 5500), and some sort of mild duration, .500-ish lift cam with a lobe seperation of around 116 degrees. I know most cams don't spec out like this, but I figure if a 342 cubic inch LS1/2 can make 400 hp at 5500 RPM, and have good street manners, a 331 SBF with some AFR heads should be able to get close.

OK guys help me out. I've read all the articles, and seen all these awesome engines, but I don't have much real world experience. What kind of results have you achieved with these mods?

[Intmdtr]

your rpm is a direct result of your intake. a better intake system will help to open up your rpm's, but with that you will need to upgrade your cam and heads as well. but with any upgrade you will need to upgrade other things as well. i suggest a complete system setup like the TFS H/C/I kit, fairly inexpensive and well worth the money. also you will need to upgrade the exhaust aswell. more air requires more exhaust but this is something you more then likely understand.

[rrrcustom]

I do understand that upgrades should be made as a system for the best results, but, which ONE upgrade is going to make the biggest improvement? Again, based off experineces.

Even if the answer is I won't get enough improvement from any one upgrade, that would be a good one, but will an intake alone increase my RPM range? I'/ not looking for a huge jump in HP right now, but an increase in the powerband, and USEABLE HP.

If an intake will increase the powerband by itself (or even just shift it), what is everyone's experience with the Edelbrock RPM manifold? I had a buddy that put a standard Performer on his 5.0 way back when they first came out, and I remember with gears, exhaust and the intake it was (again, from what I remember at the time) stupid fast. Since then, I've owned a 400 HP GTO and the LS1 camaros, so I'm used to faster cars. His mustang may feel slow now, I don't know.....


BTW, I already have a complete exhaust on the car. BBK Equal length headers, Magnaflow X pipe, and Magnaflow cat back. I also have the BBK CAI, so it's not still stock.

[Intmdtr]

well if i was going to do it i would look for a good set of used aluminium heads or new if you so choose and then i would do a home port job on your intake (gasket match) and see if that gives you the jump your looking for. remember 9/10 times used parts are just that, used and someone has gone to a different setup. people generally don't try to sell something if it is total crap. shop around lots of good deals out there for good used parts.

but in closing, heads on a 5.0 would be a good start point.

[lichtyr]

Ford is notorios for not breathing well thus the problem on the higher end RPM the best way to aleviate this is some head work along with a good intake and headers I port the heads and polish the RPM manifold is good along with a rpm camshaft with a bit more lift and duration on the valves this will wake up you 5.0 and help it pull up to 6000 rpm the choice of cam is important they are often built for low torque or Higher end performance but any kind will help I have a 302 with svt heads RPM cam and RPM high rise as well as edelbrock carb this thing screams at Higher rpms but is a bit doggy on the low end need to power brake it to about 2000 to 2500 to get it out of the hole but it comes on real strong after that

[already7]

An intake system might get you about what you want, especially since you have already opened up the exhaust.
The heads would get you there easier, but as you know, they really shine when combined with a good intake system.

So I would say get the intake system first and try it out, then when you decide to tear down the engine and freshen it up, or stroke it on out, THEN get some good heads and you will see it pick up some good numbers then.

[91stang308]

i too have been having that problem with my stang. I have the same stock intake setup off of my 91 gt motor but when i swapped the 91 302 for a 72 302 i lost RPM's. with the old motor i could get it to about 5800-6000 redline but with the new one its done about 5200. I was also wondering if its the cam or heads since its the same exact intake.
I always heard that a cam would let it rev higher

[hotwheels]

If i were in the same spot, i would buy the heads first, then a cam and lastly the intake. The cam is built to give the 95 fuel economy and not allot of horsepower in stock form, the intake on the 95 has it's draw backs, but it will handle some decent air flow. The heads however are junk, if you can't get decent air into the combustion chambers you will piss in the wind with any other upgrades. Now, if you too are like me and money is an issue, you may want to look at the aluminum heads they sell at http://www.tristatecylinderhead.com/catalog/ ............I agree to with all of the post's above and each one has a plus to the order chosen for the build, but the 94-95 motors were dawgs and didn't have allot of go from the start of their lives.

[jerseymike68]

I have the Magnaflow too and love it, my brother got his used from craigslist but I wanted a valid warranty so I got it here. Magnaflow Exhaust 16747, or you can try one of the sponsors here on the forum, they are allways having sales/specials. Either way its a great exhaust system, sounds great, and very easy to install.

[945.0GT]

my .02 cent would be to start at the intake , and go from there the heads are the same e-7 that where used on all the gt 5.0 after 87 and the cam is also the same . i put a set of crane 1.7 on mine but that helped the low end . now i am looking to get away from that intake with either a gt-40 , cobra or another aftermarket brand . only bad thing is you will have to buy the adaptor for the intake .