How to get around 40 more engine HP?

Red03Mustang

New Member
Apr 26, 2004
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Hey guys, how's it going? I don't know a whole lot about cars, but I am wanting to see if I can reach a 300 HP mark with my car. It has a K&N filter and Magnaflow mufflers. It is an auto. I would like to be able to say my car has 300 HP. I know that the 260 hp the car is stock with is ENGINE hp, not RWHP. I want to have 300 engine HP.

My question is, what would be modifications that I would need to do to achieve my goal? Could someone give me some good combos to put together? I'm not rich, so I'm not going to be able to go the turbo / supercharger route. I'd rather stay N/A anyway.

Also, what are the stock gears for my car? Would putting 4.10's in it be too high for a daily driver, or should I put 3.73's (unless that is what it has stock)?

Also, what good is an aftermarket throttle body, and should it be included in the mods for gaining 40 extra engine HP?

Thanks in advance!
 
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Stock gears are 3.27, 4.10s aren't too much for the street I'd say, but they will cut down a little on gas mileage (probably) and if you ever plan on getting blown, I'd go with 3.73 gears.

First off, go with full exhaust, with long tubes and offroad X that should net you somewhere around 40hp at the flywheel I'd imagine. Underdrive pullies would also be a good power gain.
 
maybe underdrive pullies if you never get blown. Plus all the above mentioned stuff, and a dyno tune w/ added timing may get ya there. Also N/A cams are around $550. Not sure what the install is, but you may so a search on VT engine n/a cams they pick ya up lots of HP esp. w/ LT headers, and an off road X pipe. IMO also get 410's, and a stall convertor for your trans (slips the power in like a clutch from a manual trans) Gears, and a convertor wont give you more HP, but you'll sure feel it !
 
Thanks for the responses! I'll probably do all this over time if I can. What would you guys recommend I do as a good first step? As in, what would be a good order to do these in, since I won't have the money to do them all at once?
 
Red03Mustang said:
Thanks for the responses! I'll probably do all this over time if I can. What would you guys recommend I do as a good first step? As in, what would be a good order to do these in, since I won't have the money to do them all at once?
410's
stall convertor / trans cooler
longtubes / X pipe
TB / plenum / pullies
cams / tune :nice:

just keep any eye on the tune (a/f ratio) after longtubes, and remember the tune can add the desired timing, and recalibrate the speedo for gears.
 
c2see21 said:
i got 300 (actually 299.7) flywheel from longtubes, prochamber & a k&n :nice:
Not that I'm doubting you, but do you have a dyno sheet to show these gains from LTs and a pro chamber? I'd really expect about 20 at the wheels from these mods. Was the engine pulled and put on a dyno or is this an estimate based on RWHP, and if so, what was the RWHP (and torque)readings?
 
twogts4us said:
Not that I'm doubting you, but do you have a dyno sheet to show these gains from LTs and a pro chamber? I'd really expect about 20 at the wheels from these mods. Was the engine pulled and put on a dyno or is this an estimate based on RWHP, and if so, what was the RWHP (and torque)readings?


well i have the dyno sheets right here beside me. it was done on a mustang dyno. so add 33% (per the guy that installed it from mustang dyno's) & you get my flywheel. but i can't scan it right now, my computer crashed & i lost my scanner program :( :notnice: i'll try to find a download for it & post it :nice:


btw - rwhp - 223.4, tq - 248.4 (so it's actually 297.1, 330.37) so i was a couple hp off
 
c2see21 said:
...<snip>...so add 33% (per the guy that installed it from mustang dyno's) & you get my flywheel. ...<snip>...btw - rwhp - 223.4, tq - 248.4 (so it's actually 297.1, 330.37) so i was a couple hp off

I've always heard 20% drivetrain loss on an auto and 15% loss with a stick. Is that right or not??? :shrug:

That would make your flywheel hp 279.3 on an auto, which agrees with the approx 20 hp gain estimated for your mods as quoted by one of the other guys here. :doh:
 
Jakes said:
I've always heard 20% drivetrain loss on an auto and 15% loss with a stick. Is that right or not??? :shrug:

That would make your flywheel hp 279.3 on an auto, which agrees with the approx 20 hp gain estimated for your mods as quoted by one of the other guys here. :doh:

yea he used a mustang dyno tho
 
Do you guys have any problems with passing inspection off offraod mid-pipes in NC? I'm new to the area, but I know in NJ it wouldn't fly. I bought my 99 Cobra stock about 10 months ago now and want to do exhaust work but I'm hesitant to do an off-road X/H-Pipe.
 
MustangDanny said:
Do you guys have any problems with passing inspection off offraod mid-pipes in NC? I'm new to the area, but I know in NJ it wouldn't fly. I bought my 99 Cobra stock about 10 months ago now and want to do exhaust work but I'm hesitant to do an off-road X/H-Pipe.

if you dont mind switching the pipes ever couple years...who cares? If you don't want to do that, then heres how it flies at least out here in california. If you do the catted x/h pipe you'll pass inspection, but possibly not the sniffer. With offroad, you're not going to convince anyone it's not a race car.
 
MustangDanny said:
Yeah, but I think it's every year here in NC if I'm not mistaken. Am I right NC guys?

ahh i think ur right i just talked to my aunt who lives in NC. Well, if thats the case, and you dont want to change out your pipes yearly, then id suggest getting a catted one, and find a shop near you...and get on their good side. Visit them a lot for work and crap, then when it comes time to smog test...maybe they'll ignore the sniffer. heh
 
I think NC rules are different by county. I live in a county next to Mecklenburg (Charlotte) County, and if you're county touches that county, then you have to pass full emissions. Starting next year or 2006, anything before 1996 doesn't have to pass emissions anymore. But I know for mine ('99 Real 35th Anniversary Edition - Performance Red), it has to have cats and all to pass.