1998 Mustang Cobra Engine Work Question?

[98mustangcobra]

Hello I have a 1998 Mustang Cobra. I Threw A Rod. So i am getting New Forged Pistons that hold 1000+ Hp , H-Beam Rods that hold 1200+ HP , and Crank that is good for 1000+ HP.

First of all I would like to know if and if so how much Horsepower would adding this most likely give me?

Secondly does anybody have any suggestions of anything else that is a good Horsepower gain that i should do while my engine is apart?

How much Horsepower does Porting and pollishing your heads give you? And Cost?

Lastly Should i get a high performance Fuel Pump or Fuel Injectors?

It would really help me greatly if i could get all these questions answered and get told a close amount of horsepower each thing should give me. Thanks for your time i hope to hear back and have a great day.

[Unit 5302]

First off, this topic belongs in the Modular Madness forum; however, I will answer some of your questions below.

1) No. The parts you're adding to your engine will REDUCE the amount of horsepower you're going to make because they will be heavier than the parts they replace. Your engine will be stronger than it used to be, but with the same displacement, same air/fuel delivery and exhaust,t he extra weight will cause you a parasitic loss in total performance.

2) You should focus on power adders (forced induction) with your engine rather than keeping it naturally aspirated, IMHO. If you're set on keeping the engine NA, camshafts are a big boon to your setup.

3) The cost and performance gain of porting/polishing your cylinder heads are likely proportional to one another. The better or more aggressive the port/polish job is, the more time and experience will likely be involved so you'll pay more. A basic port job may run you just a few hundred dollars while an aggressive professional porting and polishing job will run well upwards of $1,200. With your engine, you might expect to see as few as 20hp for a few hundred, and as much as 50hp+ by aggressive porting IF depending on whether you add additional parts. When you're adding NA horsepower, you often have to look at replacing multiple parts, and you often lose drivability on a small displacement engine like your Cobra's 281ci (4.6L) V-8.

4) This again, would depend on how much power you're adding.

[bmxmon]

I really dont know much about the 4.6's, but from what i've heard its best to upgrade the 96-98 4.6's to the 99 and up heads. (PI??) I really have no idea if perhaps you do have (or equivalent) those heads since it is a cobra.

[blue00gt]

Originally Posted by bmxmon

I really dont know much about the 4.6's, but from what i've heard its best to upgrade the 96-98 4.6's to the 99 and up heads. (PI??) I really have no idea if perhaps you do have (or equivalent) those heads since it is a cobra.

PI stuff is for 2V motors, not 4V like the Cobra has.

[blue00gt]

Basically, if you are not planning on making the 1000+ hp that those internals support, then there is no reason to get them. Since your block and stock crank can hold up to alot of punishment, just get some decent forged rods and pistons and save yourself the cash and extra rotating mass.
Whether or not you need bigger injectors or a pump to support more fuel flow also depends on what your setup and power goals are going to be.
You need to set yourself up with a power goal you are trying meet and decide whether you are going to do it N/A, or with nitrous or forced induction. Then you can select your parts based around this stuff. Do you drive the car everyday? Do you roadrace it or drag race it?
If I were you I would just build the bottom end like I described and add a blower or turbo kit like Unit said and be done with it. Bolt-ons and headwork, etc. all add up fast as far as cost and aren't going to get you anywhere near the power level that forced induction will for the money. If you go with forced induction, you can enjoy all that power right away and still add the other parts later if you get bored with the kind of power you're making.
With the 4V motors it's pretty easy to get into the 400-600rwhp range with forced induction. You also need to keep in mind that if you plan on making big power then your stock clutch, tranny and rear end aren't going to hold up to it either.

[98mustangcobra]

Hello Well i am planning of having anywhere from 600-700 HP for now and then later i might look at a Turbo or SuperCharger. I am thinking the SuperCharger unless i have another car to drive by that time. Yes i use this as a day driver and in street racing not on drag strips. To help you in helping me i will List the Mods i am planning on getting and you can tell me things you think are a bad idea if any or anything you may suggest. Thanks

My Mods for my 98 Mustang Cobra
(This is only engine mods not looks.)

1) The Crank Pistons and Rods i mentioned. (Do not know about HP)
2) Bassani Mid Length Headers (Said to give 30HP)
3) Bassani Offroad X-Pipe (said to give 15HP)
4) Bassani Mufflers (Do not know about HP)
5) Underdrive Pulleys (said to give 15HP)
6) Throddle Body Spacer (said to give 15HP)
7) 60lb Fuel Injectors (Dont know about HP)
8) Horsepower Chip, And Suggestions??????
9) I would like to know how to remove govoner????:??
10) Performance Fuel pump (Dont know anbout HP)
11) Port and Pollished Heads (Said to give 50HP)
12) Get the Car profecionally Power programed (said to be 80HP)
13) Boost Cooler Water Methanol Injection ( Said to give 78HP in 5.0 mustang and super fords magazine)

My Car already has stock 307 HP with Rebuilt Tranny with 130 Miles on in, King Cobra Clutch with 130 Miles on it, New Performace Clutch Wire with 130 Miles on it and an K&N Air Intake. And all 4 tires Brand New.

Thanks for your time returning my questions and have a great day.

[bmxmon]

Thanks blue00gt, like I said I dont know much about the 4.6's and the late model stuff.

[Jeff Chambers]

Originally Posted by 98mustangcobra

Hello Well i am planning of having anywhere from 600-700 HP for now and then later i might look at a Turbo or SuperCharger. I am thinking the SuperCharger unless i have another car to drive by that time. Yes i use this as a day driver and in street racing not on drag strips. To help you in helping me i will List the Mods i am planning on getting and you can tell me things you think are a bad idea if any or anything you may suggest. Thanks

My Mods for my 98 Mustang Cobra
(This is only engine mods not looks.)

1) The Crank Pistons and Rods i mentioned. (Do not know about HP)

No real HP gain unless you're going to increase the compression ratio. 12:1 is possible here.

2) Bassani Mid Length Headers (Said to give 30HP)

Good header but not 30HP worth. Remember to take every advertised HP rating, divide it in half then throw away half of that.

3) Bassani Offroad X-Pipe (said to give 15HP)

Might see 15 here with the headers helping out.

4) Bassani Mufflers (Do not know about HP)

No effect.

5) Underdrive Pulleys (said to give 15HP)

No more than 7 at the wheels.

6) Throddle Body Spacer (said to give 15HP)

0-5 has been my experience.

7) 60lb Fuel Injectors (Dont know about HP)

No added HP, just more capability.

8) Horsepower Chip, And Suggestions??????

A custom chip with tune might net you 15 to 20 at the wheels depending on how far off your combination is to begin with. Drivability can be much improved though with the H/C/I/Injector/MAF combination.

9) I would like to know how to remove govoner????:??

Done in chip.

10) Performance Fuel pump (Dont know anbout HP)

No HP improvement.

11) Port and Pollished Heads (Said to give 50HP)

This is in the ballpark. Good cams will add even more.

12) Get the Car profecionally Power programed (said to be 80HP)

See my comments on the chip. 80hp is an unreasonable expectation, especially N/A.

13) Boost Cooler Water Methanol Injection ( Said to give 78HP in 5.0 mustang and super fords magazine)

I warn all my customers away from these. These are a meltdown waiting to happen.

My Car already has stock 307 HP with Rebuilt Tranny with 130 Miles on in, King Cobra Clutch with 130 Miles on it, New Performace Clutch Wire with 130 Miles on it and an K&N Air Intake. And all 4 tires Brand New.

Thanks for your time returning my questions and have a great day.

See my comments above. You're planning on 600-700 BEFORE a power adder? How? That would be 2-3 hp per cubic inch which just isn't going to happen whether its a 2V or 4V without spending mondo $$$. I've got $35,000 in my pushrod motor spinning it to nearly 10,000 rpm and only net about 2hp per cubic inch. 600-700 with a turbo is doable although you're looking at the better part of $10,000 to do it right (Hellion, HP, etc with all the fixin's).

[98mustangcobra]

Hello i am really looking into getting this kit so i really would like to know more about why you say this.

13) Boost Cooler Water Methanol Injection ( Said to give 78HP in 5.0 mustang and super fords magazine)

I warn all my customers away from these. These are a meltdown waiting to happen.

[98mustangcobra]

Hello i have another question about you saying A custom chip with tune might net you 15 to 20 at the wheels depending on how far off your combination is to begin with. Drivability can be much improved though with the H/C/I/Injector/MAF combination.

What is the H/C/I/Injector/MAF combination
Where can i get this
What do i look under to do this or get this? Thanks

[The Deuce]

You're going to wast your time & money trying to put together a motor like this.

There's a guy around (Duane V) who's done everything you can think of to his n/a 98 cobra and doens't make 400hp.

If you want serious power, put a procharger on it and call it a day. You'll thank me later.

[Jeff Chambers]

For the water/meth systems to make the advertised power, two things have to happen; (1) the air/fuel mixture has to be leaned and (2) boatloads of timing have to be added.

As soon as the water/meth sprays, the A/F will drop a full point. That means that if you're boosted and your target A/F is 11.5:1, it falls to 10.5:1....way too rich. So the tuner takes fuel out to bring it back to 11.5:1. Secondly, a bunch of timing is added. I've had to add as much as 12-degrees at WOT to get power gains of 60hp on a 400hp blown combination. All this is fine when the spray is there. However, when the spray isn't, you've got conditions that are perfect for a hurt motor. The A/F is now a point or more too lean and the engine has way too much timing. BOOOM! These systems are notorious for the pumps failing and injectors clogging. Not to mention that its very easy to run out of the mixture and not even know it. I've seen too many engines hurt with these systems. I'd rather see a small wet shot sprayed in front of the blower. At least with a 50-75hp shot, there are no significant changes in the tuning. So if the shot fails, everything is the same as without the shot to begin with.

[Jeff Chambers]

Originally Posted by 98mustangcobra

Hello i have another question about you saying A custom chip with tune might net you 15 to 20 at the wheels depending on how far off your combination is to begin with. Drivability can be much improved though with the H/C/I/Injector/MAF combination.

What is the H/C/I/Injector/MAF combination
Where can i get this
What do i look under to do this or get this? Thanks

H/C/I is head/cam/intake combination. This is going to be whatever you select. You need to look at injector/MAF combinations (as well as fuel pump) that support your goals. If not selected properly, they're not going to work together optimally and you may even run out of fuel.

[98mustangcobra]

First of all what do you mean by Wet Shot? Are you talking NOS. I was not really goin toward Nos. But i could change my mind. Do you think it is a smart idea or not? Thanks and have a great day.

[Jeff Chambers]

Yes, a wet shot of nitrous. Nitrous, when used sensibly, is a good safe alternative. My recommendation is a wet shot over the meth any day of week.

[98mustangcobra]

Another question. Well i have a cracked engine Rod. But i was driving when it happened and it still drove. A mechanic even told me that is should run just as we all know that is not a smart or cheap idea. And it stated and ran for me to take it to get looked at on 2 different days. and now for some reason it will not start. It cranks and sounds like it wants to start but it just wont fire up. It has full oil and gas. Do you have any ideas what it may be? Thanks and have a great day.

[Jeff Chambers]

How do you know it cracked a rod? Has an internal inspection been done? Compression/lleakdown test? Running with a cracked rod is not a good idea. If the rod breaks, the damage could be extensive, including breaking the block, damaging valvetrain/heads, etc. If its cracked, get it to a mechanic ASAP before the damage becomes even worse.

[98mustangcobra]

oh i am not driving it. it has been sitting sence i took it to get it looked at. No it has not been ripped apart but 3 different places have told me the same thing witch is a cracked rod. Why could it be anything else?

[Jeff Chambers]

Just wondering how they diagnosed it as a cracked rod. I'd be awfully hard pressed to diagnose a cracked rod without having done an internal inspection. A cracked rod is pretty much going to do what it needs to do until it breaks. What are the symptoms?

[98mustangcobra]

all i know is that once it hits 2000 RPM's you hear a tap tap tap noise of metal. Not good. That a good sign to not drive it till its fixed. They just told me that it was a broken or cracked rod. Do you have any ideas? Thanks and have a great day.