Turbo Sho Hickups under wot above 6-7psi

[TT SHO PROJECT]

Ok now with a couple days of boosting the car around i have noticed something... now iv only WOT'ed it a couple of times. but it seems that if i gun it and boost passes 6-7psi it starts to hickup (kinda like a bad miss fire...) what could cause this? any ideas?

-Bob.

P.s. it has stock maf(suck thru) and stock injectors(with 12:1 fmu).

 

[sho_sc]

Plugs?

 

[Ishodu]

All the lack of supporting mods for a boosted engine is my guess.

 

[TT SHO PROJECT]

yeah my thought is probably maxing out the maf... its fine at like 5psi or so.. but anymore and it hickups... i can boost it around all day with 50% throttle and hual a** but if i go WOT it hickups. and boy is it ever quick at 50% throttle Much faster than a stocker at 100% hehe. 2nd gear 50% down on the loud peddle and its loseing traction. never had traction problems before with it being stock. (well a lil slippage in the top end of 1st...) so theres a good chance the mafs maxed out... its good for 300hp(so i hear) witch is an easy number to hit with the turbo i have... any more ideas would be nice... i really want to get the bugs worked out on this thing as its a blast to drive! really a head turnner when ppl hear the turbo wherling and the bov going Crack WOOOSHHHHH =)

-Bob

 

[TT SHO PROJECT]

Plugs?

that thought has crossed my mind... but the car runs liek a champ not a single miss at idle or cruzzin around... only does this under boost... i really dont think this turbo pushes enough air to blow out the spark so i really dont know.

 

[Toolman]

The MAF will more than 300hp worth of air, it just does not have the electronics to read that much air. By that I mean it's voltage is maxed past that. I am not seeing that as the problem though. I would look first at your injectors.

And Marcel has a point. You are really playing with fire. If something is worth doing, it is worth doing right. At the least, get some gauges (fuel pressure and wideband) and see what is going on. If your not getting enough fuel, that is a bad thing. Don't blow this up, especially with all the work you have put into it. BTW, what did you address to fix the boost problem? Last I remember you were only seeing a 3psi max.

 

[TT SHO PROJECT]

The MAF will more than 300hp worth of air, it just does not have the electronics to read that much air. By that I mean it's voltage is maxed past that. I am not seeing that as the problem though. I would look first at your injectors.

And Marcel has a point. You are really playing with fire. If something is worth doing, it is worth doing right. At the least, get some gauges (fuel pressure and wideband) and see what is going on. If your not getting enough fuel, that is a bad thing. Don't blow this up, especially with all the work you have put into it. BTW, what did you address to fix the boost problem? Last I remember you were only seeing a 3psi max.

Very bad leak at the back manifold... i had to replace the studs... that fixed the low boost problem.. i was running Open 3" exhaust at the time so it was hard to hear a leak over the note of the car.. i didnt hear the leak till i quieted the car down running it thru the mufflers out back (i installed a 3" cut out for the track).... well i am happy to hear someone say teh stock mafs worth more than 300hp... thats a good thing... i know i need to get injectors and a fuel pump.... but that will have to wait.. for now i have the PIP unpluged for ******** timeing as insurance.. i dont ever take it past 4500 rpms so im figureing i can drive it around like this till i get a new fuel system as long as im not going WOT or past 4500.

 

[SASHO91]

hard to hear a leak over the note of the car....QUOTE]


note of the car.....

:laugh_ti: :laugh_ti: :laugh_ti: :laugh_ti: :laugh_ti:

thats not a note.. thats just f'in loud.......

 

[TT SHO PROJECT]

hard to hear a leak over the note of the car....QUOTE]


note of the car.....

:laugh_ti: :laugh_ti: :laugh_ti: :laugh_ti: :laugh_ti:

thats not a note.. thats just f'in loud.......

Lol yes this is true i agree.. WAY to loud! lol

 

[Toolman]

well i am happy to hear someone say teh stock mafs worth more than 300hp... thats a good thing... i know i need to get injectors and a fuel pump...

I don't think you quite understood. I am in no way recommending that you keep running it with the stock MAF. I was just pointing out that the MAF size itself is not a restriction. The stock TB size is what, 63mm? ANd we know it will flow over 500hp. Especially in a FI app, the 55mm MAF size will FLOW more than enough air to support 300hp, but the electronics will not MEASURE enough air, and that is not a good thing. I don't have a chart in front of me that shows the curves for respective MAF's, but the 55mm flow chart is WAY less than say an 80mm Lincoln. You can get a brand new 90mm Lightning MAF for less than $100, and used 80mm Lincoln MAF's can be had for $50 or so. I suggest you get a larger MAF right away. Even though that may not be the cause of your hickup right now (I am guessing the injectors is the culprit at this point), it is something that needs to be addressed before you go any further.

 

[TT SHO PROJECT]

I don't think you quite understood. I am in no way recommending that you keep running it with the stock MAF. I was just pointing out that the MAF size itself is not a restriction. The stock TB size is what, 63mm? ANd we know it will flow over 500hp. Especially in a FI app, the 55mm MAF size will FLOW more than enough air to support 300hp, but the electronics will not MEASURE enough air, and that is not a good thing. I don't have a chart in front of me that shows the curves for respective MAF's, but the 55mm flow chart is WAY less than say an 80mm Lincoln. You can get a brand new 90mm Lightning MAF for less than $100, and used 80mm Lincoln MAF's can be had for $50 or so. I suggest you get a larger MAF right away. Even though that may not be the cause of your hickup right now (I am guessing the injectors is the culprit at this point), it is something that needs to be addressed before you go any further.

ohh ok i see yeah i read it wrong. so like what i need or should get a bigger maf injectors fuel pump fpr and injectors and a chip or tweecer (ack $$$$$) lol well i was figuring i wouldnt be able to run all the stocker stuff... but for now its fun as long as i dont really beat on it i think it should be ok for a lil bit... i just have to keep my hands off the boost controller and my foot lightly on the gas

 

[SHeepsclOthing]

Make sure the plugs and wires are new. It doesnt always make a big difference on a NA car, but boosted its a huge concern.

 

[TT SHO PROJECT]

Make sure the plugs and wires are new. It doesnt always make a big difference on a NA car, but boosted its a huge concern.

ok so i Probably will need new plugs and wires.. as i dunno when they was changed last (i never did it) should i get 1 step colder? or 2? copper plugs? or irainium?(spelling?)

 

[silversho89]

Respectively, and IMO, i dont think you should drive the car even limping around until you get these issues resolved. i wouldnt chance a project like this.

Rob

 

[SuperchargedSHOguy]

ok so i Probably will need new plugs and wires.. as i dunno when they was changed last (i never did it) should i get 1 step colder? or 2? copper plugs? or irainium?(spelling?)

Denso IK20s for the plugs and motorcraft or taylor wires. The plugs are pricy, but they were highly recommended to me.

 

[sho_sc]

The increase cyl pressure, due to boost, will cause a miss if the plugs and wires are not at their best. Change plugs first, copper core or Iridium, to see if the "hicup" goes away. The the more costlier wires next.

Just a friendly FYI; if you hear knock under moderate to high level of boost, it's too late, you have broke a ring landing.

 

[1slickRED89]

how is that holley red pump doing? any comments on that.

 

[SHOMurph]

yeah its probably alot of things.

You definately need big fuel pump, bigger injectors and some kind of programming. Then hit a dyno.

You are trying to dump a keg of beer into a pint glass.

 

[TT SHO PROJECT]

The increase cyl pressure, due to boost, will cause a miss if the plugs and wires are not at their best. Change plugs first, copper core or Iridium, to see if the "hicup" goes away. The the more costlier wires next.

Just a friendly FYI; if you hear knock under moderate to high level of boost, it's too late, you have broke a ring landing.

i dissagree with the knock statement i drove my stang around for about a year with teh wrong ecu running WAY lean.. it rattled and knocked all over the place when i boosted it... (honest human mistake) the pistons where stockers 155k miles.. came out looking like new no damage.. re ringed it and it was new again (blown head gasket from running lean) so i do know the sound of lean knock.. like marbles in a tin coffe can. sorry just thought id bring that up.

 

[TT SHO PROJECT]

how is that holley red pump doing? any comments on that.

i scrapped the low mount t3 setup.. so no holley red pump anymore just a normal oil return line tapped to the pan (witch keeps braking on me) im running a 16g turbo now mounted under the hood drivers side.