Weird thing happens at WOT

[str8stang036]

I recently installed a Vortech S-trim, 42's, typhoon intake, 80mm ProM,Mallory Hyfire ignition and Tweecer. When I punch that I get to about 4000 or 4500 the car just like stops power. It doesnt shut down, but it does feel like a rev limiter. I turned off all the rev limiters using the tweecer, and I set the rev limiter on the Mallory to 6k.

This only happens when I punch it, but not if im just getting on it little by little. Ive only felt this in 1st and 2nd gear. what do you guys think it is?

 

[urban96]

fuel pump / fuel pressure alright?

 

[str8stang036]

My fuel pump is close to a year old. Its a 255lph. I still have the stock fuel pressure regulator on there. Before the blower it never did this.

 

[95snoozer]

what injectors and are you running an fmu?

 

[str8stang036]

42's no FMU

 

[Gearbanger 101]

Maybe you've run out of cam or valve spring? What does the rest of your combo look like?

 

[str8stang036]

Ive never heard of that Gearbanger. The car still pulls, but its like hitting a wall. The car like shuts down (dont mean power) until the RPM's come back down then it starts up again.

My H/C are stock and so is the block. I have the same combo as RC, but mine is 5spd

 

[Gearbanger 101]

The fact that it's falling on it's face so early is leading me to believe that you’re getting a little valve float with the stock springs? It's common with the weak factory springs in general and I would think the problem would be compounded under forced induction. You've got forced induction pumping through an 80mm Mass air meter, through a high flow throttle body (I presume?) with a free breathing intake and then it all falls on it's face when it runs into the tiny ports and spongy valve train with the stock heads. It’s just an educated guess, but aside from spark issues, that’s what’s setting off bells in my head right now.

 

[str8stang036]

I have a 70mm TB. But its only in 1st and 2nd gear. I was on the highway the other day, I down shifted to 4th and it took off and I was within 5k with no problems.

 

[Mikal]

what are you doing with your fuel curve? have you tuned it with a wideband? If not, i wouldnt be getting on it.

do you have an after market igniton and coil? This could be many things. Make sure you tune is good = AFR and timing. If those are right look for mechanical problems.

-Mike

 

[95snoozer]

I have a 70mm TB. But its only in 1st and 2nd gear. I was on the highway the other day, I down shifted to 4th and it took off and I was within 5k with no problems.

ah if its only in 1st and second... then my gues would be valvetrain


the fast ramprate on the springs in 1st and second will cause the valves to float earlier sometimes

just liek a car can run out of steam at a lower rpm in 1st as it does in 3rd

I would also wonder about the spark. what are your plugs gapped at?
but I doubt this is it, because it would be worse in 4th than in 1st

 

[Rootus]

You sure you're not blowing out the spark? What are the plugs gapped at? Classic problem with blown engines.

Dave

 

[str8stang036]

my plugs are gapped at 30. My coil is still stock, would that make much of a difference if it was aftermarket.

Its weird because RC has the same setup as I do expect for the 42's, and MAF, and this doesnt happen to him. It probably is spark blowout.

 

[Rootus]

My brother's S-trimmed '90 LX would blow out the spark at 4500+ RPM, no matter what he gapped the plugs at, until he got his MSD 6AL setup installed. He already had an MSD coil.

Dave