Skwerl's first hot rod

[skwerl]

I don't know enough about tuning to judge, but I do know that Justin's tunes are safe in spite of the high power levels he can get. I believe there are built in safeguards in the computer that will do things like pull timing if it senses detonation and Justin doesn't disable those safeguards like some tuners. I'm amazed at the power my car makes and looking forward to even better numbers once I get the new cams in.

 

[tigerhonaker]

6300... isn't ok?

I would not run an STB in the S197 chassis unless I was driving a car with gigantic hoosier race slicks at all four corners. It would be very unlikely that car would have a supercharger on it - think Boss 302 engine.

That Hennessey piece looks like some fine ballast.

I'm not sure which Mustang you are referring to with turning it, 6300 RPM.

But I can tell you when my 08 Bullitt Mustang was Stock with basically a Tune, 4:10 gears, I hit the Rev-Limiter many-many times in 1st & 2nd gears.

That limiter from the factory is set at approximately 6600 RPM.

I ran the crap out of it and never gave it a thought.



Terry

 

[eighty6gt]

Hehe, Terry the reason I was concerned is I have a maxed out M90 on my Bullitt and I hit the 6500 rpm limiter occasionally myself! Back when it was stock I was even more aggressive!

It seems like high cylinder pressures at low rpm (ie: huge low end torque,) is what kills these rods. I never worry about spinning it high at WOT. The torque drops off a bit!

 

[AutoXRacer]

Be careful, the stock limiter is horrible and dangerous for the life of your motor.

Remember, stock limiter pulls fuel not spark. Rev limiters ideally (for safe and accurate limiting) should turn off spark, not fuel.

When cutting fuel, you make go lean and boom!!
All the tuners I've spoken to say to stay away from the rev limiter if you cherish your motor's life.

 

[19COBRA93]

Be careful, the stock limiter is horrible and dangerous for the life of your motor.

Remember, stock limiter pulls fuel not spark. Rev limiters ideally (for safe and accurate limiting) should turn off spark, not fuel.

When cutting fuel, you make go lean and boom!!
All the tuners I've spoken to say to stay away from the rev limiter if you cherish your motor's life.

The rev limiter will never hurt your motor. Yes it pulls fuel, but it doesn't lean it out, it cuts if off entirely. No fuel = no fire. It is an internet myth that that type of limiter hurts your motor. The factory wouldn't design it that way if it did.

 

[BadPiggy]

The rev limiter will never hurt your motor. Yes it pulls fuel, but it doesn't lean it out, it cuts if off entirely. No fuel = no fire. It is an internet myth that that type of limiter hurts your motor. The factory wouldn't design it that way if it did.

I'll second this.
If there's no fuel, there's nothing for the spark to detonate.
Spark from a spark plug damn sure isn't gonna burn a hole in a piston.
If someone knows of a case where this happened, PLEASE provide the info.

 

[AutoXRacer]

The rev limiter will never hurt your motor. Yes it pulls fuel, but it doesn't lean it out, it cuts if off entirely. No fuel = no fire. It is an internet myth that that type of limiter hurts your motor. The factory wouldn't design it that way if it did.

I agree rev limiters do not hurt motors, I lived in my rev limiter when I raced Mazda Miatas. Coming into a corner, we all bounced off the rev limiter, although I believe Mazda cuts spark. Anyway, the motor went beyond 250,000 miles without issues.

So why do tuners advise not to activate the rev limiter on modded engines?
Why do race cars/motors cut spark only?

Would be nice if it was an internet myth...

I'll second this.
If there's no fuel, there's nothing for the spark to detonate.
Spark from a spark plug damn sure isn't gonna burn a hole in a piston.
If someone knows of a case where this happened, PLEASE provide the info.

Ideally, that's the case and in a bone stock setup won't be an issue.
But you every well know that there will be a condition where you get partial fuel delivery between the time the fuel is delivering and the moment in time where its cut. You may get lucky, but then again it only takes one occurrence of detonation to total your motor.

 

[one eyed willy]

I literally ran my car out of gas at WOT and had no issues....on my way home from VMP actually,lol,2hour trip for me and forgot all about getting gas. Big difference between cutting fuel and running lean....interwebz if full of misinformation!

 

[lito]

So why do tuners advise not to activate the rev limiter on modded engines?
Why do race cars/motors cut spark only?

1) Mostly because of the strain it puts on the cam drive system.

2) Ignition cut is faster and provides pore control but you can't do that in a catted system as you will destroy the cats.

 

[RetroGT2006]

I literally ran my car out of gas at WOT and had no issues....on my way home from VMP actually,lol,2hour trip for me and forgot all about getting gas. Big difference between cutting fuel and running lean....interwebz if full of misinformation!

LOL, that sucks.. Glad to know the facts and myths though.

 

[BruceH]

IIRC it's another one of the KB "facts" on their tech pages.

 

[AutoXRacer]

Damn... I need to find a rock and crawl underneath it.

I have always been a fan of rev limiters when I used to drive and race imports.
But when I got my Mustang and started modding it, I was always told to limit the rev limiter activity.

Geez... All the fun I missed out on. lol

 

[tigerhonaker]

Damn... I need to find a rock and crawl underneath it.

I have always been a fan of rev limiters when I used to drive and race imports.
But when I got my Mustang and started modding it, I was always told to limit the rev limiter activity.

Geez... All the fun I missed out on. lol

Just my (Opinion) but if a Bullitt (Stock) Mustang was going to Blow-Up from Hitting the Rev-Limiter mine would have Blown-Up years ago.

Now as I got better at driving it with the 4:10 gears I obviously very seldom hit it.

But in the beginning it was no big deal to me if I hit it and it did happen pretty frequently.

Once again my (Opinion), my thinking was if Ford was remotely concerned over the Customer Blowing their (Stock-4.6 Engines) they would not have had the Red-Line set at 6,500 RPM.

I figured hey you guys know that is a Very-Safe-RPM so No-Worries !!!

As I said I ran the crap out of mine and loved every minute of it.

I actually have found that the more Modified I had mine done the less frequent I ran it, (Wide-Open) on the street.


Terry

 

[KyleB]

Got me some rods and pistons ordered! Saleen extreme parts... Looks like I have a hybrid Roush Saleen now lol

 

[Timmbo]

I'm amazed at the power my car makes and looking forward to even better numbers once I get the new cams in.

As am I. You got one helluva bang for the buck with your upgrade. And all this without GT 500 pumps right? Damn. I guess I just like spending money LOL!

 

[skwerl]

Tim, I have the GT500 fuel pumps. With the stock pumps I ran out of fuel pressure the first time we ran it up on the dyno with the 14 lb pulley. We made 640 but my fuel pressure was down to 19 lbs at the top. Now I'm good with duty cycles about 78%.

 

[AutoXRacer]

Tim, I have the GT500 fuel pumps. With the stock pumps I ran out of fuel pressure the first time we ran it up on the dyno with the 14 lb pulley. We made 640 but my fuel pressure was down to 19 lbs at the top. Now I'm good with duty cycles about 78%.

Are you running the GT500 pumps with the voltage booster too?
With my setup I have to run the booster and dual pumps... I was in the 70% duty cycle range.

Got me some rods and pistons ordered! Saleen extreme parts... Looks like I have a hybrid Roush Saleen now lol

Is this a stroker kit or stock stroke?
What are you going to do for a block?

 

[GallopingFord]

I believe he is running the VMP VB (IIRC he said that in my thread)

 

[Pentalab]

6300... isn't ok?

I would not run an STB in the S197 chassis unless I was driving a car with gigantic hoosier race slicks at all four corners. It would be very unlikely that car would have a supercharger on it - think Boss 302 engine.

That Hennessey piece looks like some fine ballast.

The 2010 cars with the same 4.6 motor all have a 6500 redline. The bullitt cars also have a 6500 redline. The 05-09 cars have a 6300 redline.

The STB does indeed work. It's like closing off the 4th side of a rectangle. Two of the steeda STB's will easily clear the blower.

Jimbo

 

[AutoXRacer]

The STB does indeed work. It's like closing off the 4th side of a rectangle. Two of the steeda STB's will easily clear the blower.

Jimbo

But not clear the stock hood.