My 1st trip to the track I ran a 13.5 @ 100 (99.6 actually, lowest run was 98) with my stock car. I noticed at the time that going into 4th the car would stumble slightly. It wasn't fuel cut because it wasn't that severe, it was more like the engine just 'missed' for a split second. I was running 2.0 60' times (it was very very cold) and 80 - 82 MPH in the 1/8. Looking at my slips I knew the 1/4 trap should have been higher, but didn't really care. A few weeks ago I got DynoFlashed & added a MBC. Off to the track I went thinking I would kick ***. I didn't. The car ran 85 MPH in the 1/8 (3.5 MPH average improvement) yet my best was 13.1 @ 101. Again, the car was stumbling going into 4th. It's never really bothered me because, to be honest, I don't wind 3rd out to redline and shift hard into 4th on very many occasions, until I did so this morning, and now it's bothering me . Any ideas why this is happening?

Please spare me the 'Evo ain't a drag car' comments though because the same exact symptoms happen on the street. Also, it's not the reflash either because the car had the same symptoms before.

 

can you state what other mods you have, or do you have have a MBC and flash.... however if you have a flash, why would you still need a MBC?

Maybe if the car is stumbling is because you're hitting boost spike at the fuel cut range??? not sure.. just throwing out ideas.

 

Buschur filter, DynoFlash, and Perrin MBC is all I have. Like I said though, it did the exact same thing when stock. I have the MB because I wasnted to have the ability to turn the boost up (I run 20 PSI)

 

Is it missing? If so, gap your plugs tighter.

 

It feels like it's missing but I'm not sure if it is - it's odd. What should the plugs be gapped at, .035?

 

NO!!!! Trust me and gap them between .025-.027

Anything gapped over .029 will miss at your boost levels. Also, I STRONGLY recommend you switch to denso IW24's. They are 1 heat range cooler helping to quell detonation, and are a better plug.

 

I agree to check to see if your plugs are gapped correctly or to see if any of them are fouled

 

You need a new set of plugs and gap them 24 - see if that removes this issue

Also - what psi are you running ? Do you have a fuel pump upgrade?

 

BTW - my through the mail reflash is quoted at 12 - 15 whp PEAK gain - the main part you see on the strip. a 3 mph gain in the 1/8th shows me you got the rigtht amount of gain on the flash

The main differnce with the through the mail flash is in the broader and flatter trq curve and smoother feel

 

Don't mean to hijack this thread, but...

Al, are there any other alternatives to the walboro pump (I don't want any noise)? I have heard of people using the pump off a supra tt. Do you know what kind of work would be involved in going that route, or do you have any other suggestions?

Thanks
-Dave

 

Yeah, like I said before it's not the flash. I was looking at my timeslips last night and only then realised the higher MPH at the 1/8 mark. As I have said to you before: I couldn't be happier with the flash, it rocks .

I'll go buy some plugs this weekend and swap them out and report back with the results. Thanks for the suggestions.

 

The walboro is nice becuase it pops righgt in and is cheap - there are other pop in alternatives

The supra / cosmos pumps are not pop in - it requires some fabrication and modification

I prefer the pop in method