Feels like I'm hitting a rev limiter

[quickstang_1994]

At full throttle only at 5200 rpms it feels like hit a rev limiter. I have H/C/I with a vortech. Plugs are new gapped at 30(22c). I have new MSD distributor and coil and ford racing wire(also new).It is not fuel, its spark. Has anyone else had this problem?

 

[Roland69]

is that 5200 rpm's on your stock tach or a good aftermarket one.

 

[quickstang_1994]

My stock tach is dead on. It it fine free reving or even part thottle. We found out it was losing spark on the dyno.

 

[HISSIN50]

Are you to the point of needing a box to help out in the high RPM's (your combo sounds stout)? With about any decent forced induction, I would personally run a box to help things out............

Good luck.

 

[quickstang_1994]

thanks all try that it hit 421rwhp @ 4750 and we shut it off there because it hit the so called limiter there but with new dist, coil, plugs, and wires it moved to 5200. Would the tfi module affect that? I haven't replaced it.

 

[HISSIN50]

The stock ignition is supposed to be good to about 400 hp NA. Me thinks you are simply overworkin that poor stocker in the higher revs.

A bad TFI can cause a high RPM cutout, but I'm not so sure a brand new one wouldnt act the same without some spark help.

If you were plannin on a box anyhow, I would do that and if the issue still exists, then toss new ignition parts on (the box isnt added necessarily as a bonafide fix, but it's needed anyhow).

Just my two cents. Good luck.

 

[69clark]

Yeah, even if you buy a box and its not the problem, it won't be wasted money, but there is a very good chance that that is the problem.

 

[quickstang_1994]

I love NGK. I put in the plugs, let the car idle(to warm up). I took it on a test drive and wow pulled to 6000rpms with no problem it would have went farther but I was alittle scared. I'll get brave enough soon. But my plugs were the problem thanks for the help.

 

[HISSIN50]

Are the new plugs gapped the same as the old 'new' ones you had in before? I'm not too blower savvy but I am surprised that one set of new plugs caused issues and another brand took care of it (copper plug vs copper plug, no?).

I have to say that I am impressed that the stock ignition is holdling up for ya. Glad to hear you got it!

 

[quickstang_1994]

They have the same gap (set at 30). I found it hard to believe too. Ford Racing gave me the part number to get the Ford plugs but they are not made for performance, I guess. A guy on the Corral with a procharger told me to try the plugs because it cleared his up, so I figured $60 is worth a try and it worked. Some plugs may not be made for boost, I tried everything first but plugs because I had new ones in the car . But I learned from others and I'm glad I did. Ive spent way to much $$$$ on this car. I went from a strong NA car to supercharged and I added a list of problems with it.

 

[HISSIN50]

Very interesting stuff. It does seem as though NGK is popular with forced induction people (and some Mod motor folks) - I guess there is a reason.

I run them in the crotchrockets and they seem to work fine, though I'm not running 7 dollar plugs. Ouch - but a necessary ouch. Glad to hear you're up and running well.

 

[wshI_hd_1]

do u hav a good set of valve springs?...if not it could be valve float