Looking to tak my stock 4.6 l 2V around 325 350 hp

Brian's First · 06-01-2006

Just bought a 1998 gt convert 4.6 l 2v. I looking to take it to about 325 to 350 HP so I can play around while I gather parts for to build the big engine. This mustang is also an automatic.

I have been reading up on some preformence chips and cool air filter systems. I know the better it breaths the better it will help the horse power, but being new to mustangs and the modular engine looking for a little guidence form you pro's.

The 4 things I have been looking at adding to try to get to the 325 350 hp range are.

#1 new exhaust system
#2 preformence chip
#3 new throttle body either the 70mm or 75 mm
#4 cold air indduction

If anyone can add anything to get me there please advise.

Thanks Brian

BlueStreak03 · 06-01-2006

Well it sounds like you have a good start for getting the car ready for a engine buildup. However, those mods aren't going to get your car anywhere near 325 horsepower. To get a non PI 2 valve motor to that level, you need everything you've listed plus some fairly aggressive cams, ported heads and a PI intake. The good news is that you're already planning on an engine buildup.

Brian's First · 06-01-2006

Thanks BlueStreak

I was looking at intakes but being so new to mustangs in general. I need to read up a little more PI's and understand all that I have a little bit of a learning curve.

dollarbill · 06-01-2006

You have 225 at the crank now, do you want 325-350 at the crank or the tires? The cheapest way would be a 100-125 shot of nitros. Or a ported and polished, cammed, PI swapped, long tube, full bolt on with a good tune could get you up to that level but your compression will be about 10.5:1 so forget about a blower. I kinda gave up on making my 97 GT faster. I had all the parts to do the PI swap but I sold it all. I would have made about 250 or so at the tires with the current mods on the car. Those non Pi cars are just so expensive to make fast N/A. What is your bugget? A 99+ 4.6 has a better starting point to make that much power. Read up on these forums and maybe you will get some more ideas.

markwondi · 06-01-2006

Quote:

Originally Posted by dollarbill

You have 225 at the crank now, do you want 325-350 at the crank or the tires? The cheapest way would be a 100-125 shot of nitros. Or a ported and polished, cammed, PI swapped, long tube, full bolt on with a good tune could get you up to that level but your compression will be about 10.5:1 so forget about a blower. I kinda gave up on making my 97 GT faster. I had all the parts to do the PI swap but I sold it all. I would have made about 250 or so at the tires with the current mods on the car. Those non Pi cars are just so expensive to make fast N/A. What is your bugget? A 99+ 4.6 has a better starting point to make that much power. Read up on these forums and maybe you will get some more ideas.

expensive? PI intake and PI cams on your car, and you'll be alongside a 99+, while only spending $225 (125 for intake and 100 for cams).

FOr the thread starter, i'll make this simple. Buy yourself a PI intake with an aluminum crossover (found on 02+ GT's). They can be found ALL the time used for ~100-110 bucks. This will give you a nice 20hp gain.

Next, get yourself some comp cams (xe268's) and comp valve springs. You'll be looking at spending ~750 for everything, but it's WELL worth it.

Add some gears (4.10's) and a good SCT tune and that car will be VERY fun. FOr ~$1200 your car will run very hard, and make ~325hp at the crank.

BlueStreak03 · 06-01-2006

Oh yeah, every single one of us forgot the Jmod for the tranny. I'm not exactly sure of the in's and out's of it. Apparently it makes the slushbox a lot more fun to drive though.

blueoval · 06-02-2006

You forgot to add in labor on all the parts you named. Mostly the cams will cost quite a bit to put in. Buy you a set of good heads and the power will jump up their and if you ever want to put a blower on later dont go with 10.5:1 go with 9:1 or if a lot of boost go with 8:1. With PI swap good cams, you could get over 300 rwhp. I would say 2700 to do all that, that is a high rounded number.

So Money · 06-02-2006

2700 hp, does that come with a flux capacitor??????? lol

BlueStreak03 · 06-02-2006

I believe he was referring to $2700. Some people like to do their own work though. The only reason I had my blower professionally done is because I didn't have enough time to dedicate to the car when I bought it. That and I highly recommend having any forced induction professionally installed unless you have lots of experience with them already.

markwondi · 06-02-2006

Quote:

Originally Posted by blueoval

You forgot to add in labor on all the parts you named. Mostly the cams will cost quite a bit to put in. Buy you a set of good heads and the power will jump up their and if you ever want to put a blower on later dont go with 10.5:1 go with 9:1 or if a lot of boost go with 8:1. With PI swap good cams, you could get over 300 rwhp. I would say 2700 to do all that, that is a high rounded number.

you are WAY off. Heads should be the LAST mod he ever makes. The stock heads are perfectly fine. Hell, even untouched PI/NPI heads can be taken to 600rwhp.

As for compression, PI headswap takes the compression to 10.1:1, not 10.5:1 Modular motors are NOT like old pushrods. They like compression wiht boost. With a 4V, optimal compression with a blower is ~10:1. With a 2V, 9.5:1 is desirable, but 9:1 is the lowest you should go. Only thing that would dictate otherwise is a KB blower, in which case 8.5:1 is the lowest you shoudl go.

blueoval · 06-02-2006

Heads is where the power is special on a N/A car. And I would not suggest anyone try and put cams in a 2v unless you really know what you are doing and have the timing tools for them. And check out kenne bell who recommends 8:1 or 8.5:1 if you are going to any kind of serious boost. The lower the compression the more safe boost you can run, but you loss power and fuel mileage, the power is easily gained back. But I do say 9:1 is good. And he wanted 325-350 you can not get that kind of power without changeing the heads especially on non PI cars.

markwondi · 06-02-2006

Quote:

Originally Posted by blueoval

Heads is where the power is special on a N/A car. And I would not suggest anyone try and put cams in a 2v unless you really know what you are doing and have the timing tools for them. And check out kenne bell who recommends 8:1 or 8.5:1 if you are going to any kind of serious boost. The lower the compression the more safe boost you can run, but you loss power and fuel mileage, the power is easily gained back. But I do say 9:1 is good. And he wanted 325-350 you can not get that kind of power without changeing the heads especially on non PI cars.

I don't care what KB says, i know from experience... i build these motors.

325 crank horsepower is EASILY attainable without changing the heads, you are just not getting it. If you're thinking 325rwhp, then yes it can't be done with stock heads. However, ported NPI heads can make 325rwhp too.

No special tools are required to install the cams on a 4.6. Hell, the only special tool really needed is the OTC to swap the valve springs. BUt even that isn't really needed either. Snap On's spring compressor for the 2.5 GM motor will work too.

the98stang · 06-02-2006

Quote:

Originally Posted by markwondi

With a 4V, optimal compression with a blower is ~10:1. With a 2V, 9.5:1 is desirable, but 9:1 is the lowest you should go. Only thing that would dictate otherwise is a KB blower, in which case 8.5:1 is the lowest you shoudl go.

I always thought lower compression was needed for boosted cars. Hence why 10:5 compression motors can't hold that much boost. Correct me if I'm wrong...

BlueStreak03 · 06-02-2006

Quote:

Originally Posted by blueoval

Heads is where the power is special on a N/A car.

Heads are where the power is made on ANY internal combustion motor.

Lower compression isn't NEEDED for boosted cars. However there is a dynamic relationship between the two and there are other factors that this relationship affect (i.e. timing and charge cooling). Also with higher compression, you don't need as much boost to make the same power. I plan on only dropping mine to ~9.2:1 when I get my engine built up and throwing 12-14psi on top of that.

I would recommend that some people around here do more listening and learning and less forcing bad opinions and misinformation on everyone else.

carguy1985 · 06-02-2006

from what i know, with full bolts, LT, Midpipe,catback, pulleys, CAI, TB,PLenum, ETC. With the addtion of cams and a good tune, i really havent seen alot of cars past 310rwhp 99+.