260/300 rwhp/rwtq from a 5.0?!

[northy_polk]

260/300 rwhp/rwtq from a "stock" 5.0?!

I own a Camaro Mustang Challenge road race car and am working towards my competition license with NASA [Natl. Auto Sport Assn.]. The rules are changing in the next two seasons. Basically, not taking into consideration the weight of the car [around 3,100-3,200 lbs.] the new numbers for the class will be what I mentioned in the title.

One of the goals of the series is to keep it inexpensive so that the average racer can participate without having to spend twenty grand on a car. Until this potential rules revision, the Fox and 94-5 cars were in CMC and limited to about 230/275 and the New Edge and S197 cars in CMC2 were above that number. Most of the cars that run at 230-235 horsepower already have some/all of the Cobra parts and are 'freshened' to 306 cubic inches.

We currently have to run stock exhaust manifolds, but unrestricted exhaust past that. We can run underdrive pullies and all the 5.0 Cobra parts, and can have all the a/c and smog equipment deleted. Other than that, for the most part, the motor must remain stock. Stock air intake, ignition, injectors, intake manifold, etc. We can run an accusump and a road race oil pan and large radiator [must be direct fit though] and an oil cooler.

Can you guys/gals give me some real world advice on the ability of the 5.0 to put down 260/300 at the rear wheels [N/A of course] without the use of super-expensive, tricked out mods? Keep in mind these are 20 minute 'sprint' races with much of that time spent near redline. I am interested in knowing if the 5.0 can reliably and cheaply sustain this power level over the course of several seasons with approximately 16 races per season.

Recommendations are appreciated, but keep in mind that the goal is
cheap
stock [as much as possible]
reliable
260/300 at the rear wheels.

Thanks in advance for your assistance!

Jon

 

[Makdaddymac]

gt40 heads, and cobra intake, some roller rockers and a tune up should get you close to your goals.

 

[northy_polk]

I already have a stock 95 Cobra motor in my race car with all that stuff on it...makes 225/275 or so. Ideas why it's low?

 

[ShortThrow50]

I already have a stock 95 Cobra motor in my race car with all that stuff on it...makes 225/275 or so. Ideas why it's low?

Low? what do you mean? Sound about right from a mustang dyno.or maybe im wrong lol. reg 5.0 dyno's at 170-180 rwhp. Put a aftermarket cam in your car and get the heads ported

 

[northy_polk]

Low? what do you mean? Sound about right from a mustang dyno.or maybe im wrong lol. reg 5.0 dyno's at 170-180 rwhp. Put a aftermarket cam in your car and get the heads ported

I say 'low' only because some folks seem to think I should be putting down 15-20 more at the rear wheels with the Cobra motor.

Cam and porting. Unfortunately, I doubt the series directors will choose to allow the porting...maybe the cam, but doubtful. It's just very difficult to police those. Cold air intake, intake manifold, and long tubes can all be easily inspected by the tech guys at the track...but will those net 260? I don't think so, but I don't really know.

There are many other people working on this. I'm just trying to do my own 'research' and see what others out there have done to make power.

So is it unrealistic to think that one could get this power with 'bolt ons' that can be seen by the tech inspectors at the track?

 

[85_SS_302_Coupe]

This almost sounds like a Factory Street drag engine, only maybe a tad more strict if you can't more the engine over. Those guys are making over 300rwhp with GT40 heads and Cobra intakes and stock cam profiles....but they have unbelievable valve jobs and lots of tricks to make the heads flow without porting them. I can't say how to do it but it's possible.

 

[WHITE94COBRA]

In relativle stock form, my cobra put down 296 tq, and 240 hp. That was back when the only mods that were done was a borla cat back, bbk catted h pipe, and K&N filter. I think my TQ number was little lower than that but it was soooooo long ago.

 

[Mustang5L5]

Have the GT-40 heads and Cobra lower intake ported.

65mm TB, 24# injectors, delete the smog pump, a/c and p/s, cobre underdrive pullies, off-road exhaust after headers.

The camshaft is the x-factor. The cobra cam is not that good.

 

[cenok is family]

yeah your power numbers seem a tad bit low, but not unbelievably. with the mods in my sig (pretty much everything a cobra has except i'm still currently running stock e7 heads), i put down 228rwhp and 279rwtq running PIG rich with 24#ers on a dynojet. doing what 5L5 said should get you pretty dang close to your goals

 

[jwzg]

Well, GT40P's are likely a bit better in terms of their torque curve which is what you are looking for in sprint races (I assume this is road racing). Early speed density cams produce better numbers on average. I would suggest measuring your valve events to see if you can degree the cam to make better power in the range at which you'll use it. Just advancing or retarding the cam from "dot-to-dot" position will not change torque or horsepower in a predictable without knowing when your events occur. If you can get away with running an electric fan from a Mark VIII or Taurus, do it and you'll produce 15-20 extra HP at full throttle.

Tmoss on this site puts down somewhere around 280 to the rear wheels. His heads and intake have a bit of "special" work done to them, so I'm not sure if this will help you.

 

[91notch5.0]

mine makes 280 hp and 325 tq at the wheels. i think it would be very hard to do with stock stuff.

 

[Mustang5L5]

I don't know if he is allowed to use GT-40P's since they never came on a Mustang. Also, he would need p-specific headers and he is required to use the stock headers.

 

[back2fox]

I have thumper ported stock heads, CI custom cam, Tmoss ported intakes. I put down 262 rhp and 297 rtq.

 

[jwzg]

mine makes 280 hp and 325 tq at the wheels. i think it would be very hard to do with stock stuff.

That's my car in your avatar! Do you have any close-ups posted anywhere?

 

[Darkwriter77]

I would think that injectors might be a problem, as well, if they're not allowed to change those. Doesn't the stock 19# injectors' rating top out around 250 horses?

 

[jwzg]

He could either run a X3Z EEC or have a custom tune for an A9(X).

 

[Mr. Rustypwnz]

injectors' rating top out around 250 horses?

heck no about 300 is the limit, I have ran 3 cars now with h/c/i and all the bolt ons with no lean problems of yet..

 

[legalize420]

i put down 270/298 with unported heads and intake. im still running the stock injectors for now. your numbers are low.

 

[Dino Dino Bambino]

Fox and 94-5 cars were in CMC and limited to about 230/275 and the New Edge and S197 cars in CMC2 were above that number. Most of the cars that run at 230-235 horsepower already have some/all of the Cobra parts and are 'freshened' to 306 cubic inches.

We currently have to run stock exhaust manifolds, but unrestricted exhaust past that. We can run underdrive pullies and all the 5.0 Cobra parts, and can have all the a/c and smog equipment deleted. Other than that, for the most part, the motor must remain stock. Stock air intake, ignition, injectors, intake manifold, etc. We can run an accusump and a road race oil pan and large radiator [must be direct fit though] and an oil cooler.

Can you guys/gals give me some real world advice on the ability of the 5.0 to put down 260/300 at the rear wheels [N/A of course] without the use of super-expensive, tricked out mods?

Here's what you can do:

Remove air silencer from filter housing
Remove MAF housing mesh screen
Send your Cobra intake manifold to Tmoss for porting
Port the heads
Offroad H-pipe
Catbacks
Underdrive pulleys
EGR/smog/AC delete
'94-'95 electric fan (if it's a Fox body) and delete mechanical fan
Meziere electric water pump (optional)

That list should get you close to your HP/TQ goal.

 

[northy_polk]

Thanks everybody for your input. The national and regional directors are 'researching' this issue and I look forward to what they discover.

The latest information I have [as of today] is that we might be permitted to use different injectors, a new cam, and a different [or ported?] intake. Does this sound about right to get to the 260/300 mark?

What are some other things I can do to 'freshen' my stock 144k mile Cobra motor, aside from the above? New valve springs? Valves? Check clearances?

Thanks again!