n/a horsepower

[nopropslaw]

I have been looking at buying a 96-98 cobra for a project car. What kind of n/a horsepower numbers are possible. I plan on building the engine with a buddy, but coming from an 03, I don't know much about n/a potential of these motors. Which heads are best? cams? Intake? Any years better than others? I know the blocks in these years are aluminum, which is a nice weight savings.

I assume this has been asked numerous times, but I tried searching, and the only thing I found was someone posting a dyno video making 380rwhp a few threads down. Is that normal? Can higher hp numbers be had with ported heads/intake, more aggressive cam?

Thanks in advance.

 

[Blown_By_You]

I have been looking at buying a 96-98 cobra for a project car. What kind of n/a horsepower numbers are possible. I plan on building the engine with a buddy, but coming from an 03, I don't know much about n/a potential of these motors. Which heads are best? cams? Intake? Any years better than others? I know the blocks in these years are aluminum, which is a nice weight savings.

I assume this has been asked numerous times, but I tried searching, and the only thing I found was someone posting a dyno video making 380rwhp a few threads down. Is that normal? Can higher hp numbers be had with ported heads/intake, more aggressive cam?

Thanks in advance.

It will take ALOT of money to make 400 horsepower NA...

These engines are simply too small to make massive amounts of power naturally aspirated without aggressive headporting, cams, and very high RPM

 

[nopropslaw]

I assumed it was pricey. I was just wondering what part combinations have provided the best results for people. The guy that posted his dyno video used 03/04 heads with an 01 intake, all unported,cams, and then bolt ons. Just was wondering what peoples experiences were with different head/cam/intake combos, which heads take the best to porting, which intakes take the best to porting, which cams work the best with these combos, etc...

 

[97desertCobra]

I have been looking at buying a 96-98 cobra for a project car. What kind of n/a horsepower numbers are possible. I plan on building the engine with a buddy, but coming from an 03, I don't know much about n/a potential of these motors. Which heads are best? cams? Intake? Any years better than others? I know the blocks in these years are aluminum, which is a nice weight savings.

I assume this has been asked numerous times, but I tried searching, and the only thing I found was someone posting a dyno video making 380rwhp a few threads down. Is that normal? Can higher hp numbers be had with ported heads/intake, more aggressive cam?

Thanks in advance.

If you are going to stay n/a then get some 03-04 Cobra cylinder heads as they flow better than the 96-98 heads. FR500 heads are also a good choice if you stay n/a. As for cams the best FACTORY n/a cams belong to the 96-98 cams, but if you are going for n/a power then a custome grind will yeild the greatest results. To get the most out of these DOHC you will want to increase th displacement with a stroker crank, big bore block or both. If you go big bore stroker you can get 5.3L.

There are two ways to do this, you can resleve the teksid block and then run a stroker crank to get 5.3 OR you can get the BOSS 302 big bore block and a stroker crank to reach 5.3. The biggest drawback with the Boss block is going to be the added weight because it is iron.

As for the video you saw where the car made 380rwhp, that is not typical considering the mods done to his car. Not typical but not impossible either. I would consider 350-360rwhp more typical with his mods, but kudos to him for being above the curve.

My ideal n/a combo would be a big bore stoker giving me 5.3L, fully ported FR500 heads, custome cams and a either an FR500 intake or a sulivan intake. Many people may not agree with me but the sacrifice in low end power I would be making by running the FR500 or sulivan would be made up in the top end power at 8k rpms and running a much steeper rear gear. To make the most out of an n/a combo you will need to reach into the upper rpms.

So with all that said what is your hp goal and over all goal going to be with this car?

 

[97desertCobra]

I assumed it was pricey. I was just wondering what part combinations have provided the best results for people. The guy that posted his dyno video used 03/04 heads with an 01 intake, all unported,cams, and then bolt ons. Just was wondering what peoples experiences were with different head/cam/intake combos, which heads take the best to porting, which intakes take the best to porting, which cams work the best with these combos, etc...

The 99-01 Cobra and Mach 1 intake can be modified such as porting and shortening the runners. The same can be done with the 96-98 Cobra. It will gain a decent amount of power in the top end and allow you to rev the engine higher and run steeper gears.

 

[venom1997]

n/a high comp b headed motor should have no problem making high 300's porting b heads will help. Ported b heads should flow way more than stock 03-04 heads right:shrug: the exhaust ports are what need to be opened up on b heads

 

[nopropslaw]

350 rwhp would be great, and anything above that would be a bonus. Would stock 96-98 heads be better to have ported or would 03/04 heads be better to have ported? What about intakes, 96-98 or 99/01 better for porting? I'm planning to keep original displacement.

 

[na svt]

You can get 400rwhp without spending an arm and a leg. However, you are limited to 91 octane, no long tubes and emissions testing which are huge power constraints. You said you wanted to stay with the stock displacement but the easiest way by far to make big n/a power is by adding cubic inches by stroking, going with a big bore or going with both. A stroker is cheaper than a big bore and will easily get you over 400rwhp. Do not stay with the B heads if you are serious about making big n/a power as their ports are way too big and the port velocity is way to slow. Some people think that bigger is better and it's defintely not true in this case.

Aftermarket cams are needed and no stock cams will get you more than 350rwhp with 91 octane compatible compression. Aftermarket cams are needed but their duration will be limited due to the "smog" check.


You can't use a 96-98 intake on 03/04 heads and you can't use a 99/01 or Mach intake on B heads.

An inexpensive 350rwhp, 91 octane compatible combo capable of passing emissions would be:
10.5 to 1 stroker
bowl ported 03/04 heads
96-98 cams
short runner intake
shorty headers

 

[nopropslaw]

You can get 400rwhp without spending an arm and a leg. However, you are limited to 91 octane, no long tubes and emissions testing which are huge power constraints. You said you wanted to stay with the stock displacement but the easiest way by far to make big n/a power is by adding cubic inches by stroking, going with a big bore or going with both. A stroker is cheaper than a big bore and will easily get you over 400rwhp. Do not stay with the B heads if you are serious about making big n/a power as their ports are way too big and the port velocity is way to slow. Some people think that bigger is better and it's defintely not true in this case.

Aftermarket cams are needed and no stock cams will get you more than 350rwhp with 91 octane compatible compression. Aftermarket cams are needed but their duration will be limited due to the "smog" check.


You can't use a 96-98 intake on 03/04 heads and you can't use a 99/01 or Mach intake on B heads.

An inexpensive 350rwhp, 91 octane compatible combo capable of passing emissions would be:
10.5 to 1 stroker
bowl ported 03/04 heads
96-98 cams
short runner intake
shorty headers

Thanks for the reply. I have a guy who may be able to "help" my smog along if I got long tubes. I'm a little lost on the "short runner intake." Can that be done to a 99/01 intake?

Hows ported 03/04 heads, ported 99/01 intake, custom cam, intake spacer (not sure that does much), all typical bolt ons including long tubes and full exhaust.

 

[na svt]

Thanks for the reply. I have a guy who may be able to "help" my smog along if I got long tubes. I'm a little lost on the "short runner intake." Can that be done to a 99/01 intake?

Hows ported 03/04 heads, ported 99/01 intake, custom cam, intake spacer (not sure that does much), all typical bolt ons including long tubes and full exhaust.

A 99/01 intake can be made into a short runner, I've done a few and have two in progress.

The combo you mention would work well, especially with more cubic inches.

Can your friend help getting aggressive cams thru smog?

 

[nopropslaw]

A 99/01 intake can be made into a short runner, I've done a few and have two in progress.

The combo you mention would work well, especially with more cubic inches.

Can your friend help getting aggressive cams thru smog?

Yes he can. ;-)

 

[Chris _Scott]

If you are absolutely serious about making power...

I would definitely look into swapping to 03/04 heads, just note that it will require removing the engine from the car to swap

Really depends on how dedicated you are and how much work you are willing to put into it. It was a LOT of work I did to pull my motor and put it back in to gain maybe..25-30hp..but when you're N/A every little bit counts.

You can probably just get away with putting in cams, a short runner intake, IMRC deletes, EWP, and longtubes and you should get your 350rwhp goal even with b-heads.

Best of luck with whatever path you choose.

 

[Tabres]

Technically not true. You can swap the heads with the motor in the car. You have to use have to use head-bolts and can't use studs. I don't know why anyone would want to do it that way though. Can't imagine it being anything short of a huge pain in the rear...

 

[gq916]

I agree with NA...

 

[blackmagicmach]

just check out what you can do with a NA 4V, and if you can "get by somg" then you can do something in this realm....

http://www.svtperformance.com/forum...6/587145-fs-sickest-na-long-block-around.html

 

[na svt]

Yes he can. ;-)

Well in that case all options are open. Now it comes down to high you're willing to spin the engine. The more cubes you have, the lower you'll have to spin it to make power.

 

[mystical]

An inexpensive 350rwhp, 91 octane compatible combo capable of passing emissions would be:
10.5 to 1 stroker
bowl ported 03/04 heads
96-98 cams
short runner intake
shorty headers

Just curious but approximately how much would that setup cost to build? Stroker and head swap/short runner seems expensive.

 

[nopropslaw]

just check out what you can do with a NA 4V, and if you can "get by somg" then you can do something in this realm....

http://www.svtperformance.com/forum...6/587145-fs-sickest-na-long-block-around.html

Any more info on that motor?

 

[birdman941]

Being in Cali, it will be tough staying NA and making 400
without adding extra displacement.
See sig.
OP, do you have emission testing in your area?

 

[na svt]

Any more info on that motor?

13.5 to 1 compression, 324ci, Sullivan intake, ported 03/04 heads, yada yada yada.