S/C dynograph...experts tke a look

[SuperchargedSHOguy]

What plugs/wires are you running? I would guess you are having an ignition problem up top.

Yes tighten that belt like crazy.

Your numbers are low for 15lbs. Please also give complete list of engine mods.

Also did you change your programming when you went to the smaller pulley?

Well where should I start
3.12 pulley
ported t.b.
ported intake
boost pipe
890 cfm K&N
shoshop catless ss y pipe
flowmaster 40 series
I know I am missing some but I am rushed at the moment (gotta go to work)

plugs are autolite and wires I don't remember...have to check.

Vadim sent me a new chip for the 15 psi pulley and when I put it in the car would not rev past 2500 rpms so I put the old one back in haveing no choice if I wanted to continue driving it.

 

[SHOMurph]

Well where should I start
3.12 pulley
ported t.b.
ported intake
boost pipe
890 cfm K&N
shoshop catless ss y pipe
flowmaster 40 series
I know I am missing some but I am rushed at the moment (gotta go to work)

plugs are autolite and wires I don't remember...have to check.

Vadim sent me a new chip for the 15 psi pulley and when I put it in the car would not rev past 2500 rpms so I put the old one back in haveing no choice if I wanted to continue driving it.

Rich is ok until you get a good tune.

I'm assuming the autolites are the colder plugs. If not I would change either to the Motorcraft No. 9s or Denso IK22s. Also either have motorcraft or taylor wires. I would also check your gaps first. You might need to close them up a smige.

If you go with the Lightening 90 you'll definately need to change your programming.

Also go with the biggest K&N you can shove under the fender. I have a big ol' John Holmes 13 incher.

 

[AutoSHO]

How big is the exhaust piping? You'll need at least 3" to see significant top end gains. 2.5" isn't enough to make big power. Same with the air filter - its gotta be a big honkin' filter like Murph said, and it also needs to be clean.

 

[SHOMurph]

How big is the exhaust piping? You'll need at least 3" to see significant top end gains. 2.5" isn't enough to make big power. Same with the air filter - its gotta be a big honkin' filter like Murph said, and it also needs to be clean.

yep I knew I was forgetting something! Good call AutoSHO.

I have 2.5 from my manifolds dumping into a long 3 inch pipe then spliting back into 2.5s at the muffs.

Also you need to get chamberless mufflers. They will be loud but will flow lots! Magnaflow or Edlebrock RPMs are good.

 

[SuperchargedSHOguy]

yep I knew I was forgetting something! Good call AutoSHO.

I have 2.5 from my manifolds dumping into a long 3 inch pipe then spliting back into 2.5s at the muffs.

Also you need to get chamberless mufflers. They will be loud but will flow lots! Magnaflow or Edlebrock RPMs are good.

The piping is bigger than stock but I ditched the RPMs for flowmasters because I could not stand the sound of them. The airfilter is rated for lots airflow (890 cfm) and is huge as well. I have not checked the gaps on the plugs but I know for a fact the 80 mm MAF and LPM are killing me. I got the darn 90 mm and Josh's adapter harness just sitting around

 

[Sho-Driver]

Once you install the 90mm MAF, are you going to stick with your LPM? I would honestly ditch it for a TwEECer RT. That is about the only way you'll have your car safely tuned with the ability to data log and make adjustments on the fly.

 

[SHOMurph]

The RPMS may sound bad but will give you a better flow. With a SC its basically gonna sound like a hive of bees coming out of your tailpipe anyway. If you are running 15lbs you need a big exhaust and nothing you do will make it sound good. I've had three complete exhausts on my SC car and gave up on sound a longgggg time ago.

I would recommend going with to densos. Even though they are expensive I never really like the autolites (ran a set on my Gen 1 and hated them.)

All SC cars 80 and the LPM aren't great but I would make sure you have everything else working good. I had the same jagged up top as you did and closed the gap just a little bit to fix.

 

[AutoSHO]

With the way your power drops off up top I would guess that the exhaust piping is too small to support the flow you need. Even with it runnin pig rich the torque curve should not fall off the way it did. Belt slip contributes as well - I would tighten the belt more (are you running a Gatorback belt?) and schedule some dyno time with a wideband sensor.

I also agree with SHO-Driver, the only way you'll get a truly good tune on a blower car is with a TwEECer R/T. Chips can get you in the ballpark but they will never get it right on the money like you can with a tweecer.

 

[SuperchargedSHOguy]

With the way your power drops off up top I would guess that the exhaust piping is too small to support the flow you need. Even with it runnin pig rich the torque curve should not fall off the way it did. Belt slip contributes as well - I would tighten the belt more (are you running a Gatorback belt?) and schedule some dyno time with a wideband sensor.

I also agree with SHO-Driver, the only way you'll get a truly good tune on a blower car is with a TwEECer R/T. Chips can get you in the ballpark but they will never get it right on the money like you can with a tweecer.

Tweecer is coming soon...just lacking the $$$. David put on a gatorback belt and I believe the piping from the y to the muffs is 2.5? I doubt it is 3" so I may have to try to up that size. Should I ditch the resonator as well then?

I know dyno time with the wideband would help figure out the problems...but with the LPM and 80 MAF is it worth it to spend the $ on that and then buy the tweecer or just wait and tune it myself with my own wideband?

Whats a good gap for the plugs since it is s/ced or should I stay stock gap?

 

[AutoSHO]

I would go with a 3" section of pipe and put in a new resonator at that point. What is probably on the car is the dynomax piping - It is 2.5" and pretty nice quality considering the price. However, it will choke off the car up top. I would definitely keep the resonator - it does not hinder flow and makes the car sound a *lot* better. Removing it is a great way to see a lot more rasp and noise. I've never heard a SHO that sounded good without a resonator. Does your car have cats?

If you are planning on a TwEECer and a wideband, I would not worry about hitting the dyno again. If you change the exhaust it would be a good idea jsut to make sure it does not lean the car out too much at high rpms, but aside from that its just bragging rights.

Also, consider having them modify your Y-pipe to have a 3" collector to match the 3" piping if you decide to up the size. That will also help flow (and, subsequently, horsepower) considerably.

The gatorback has a lifetime warranty, but it is probably only to the original purchaser, so you may end up buying one more at some point - However, after that, they're all free. You may also want to look into the Reichard Racing pulley like Lupo has (pictures and a link were posted fairly recently), as they should also eliminate belt slippage and help you hold the boost with less wear on your tensioner and accessory bearings from the extremely tight belt.

With the copper autolites, try running on the small end of the factory gap, or even a little smaller (.042" is the factory minimum - maybe around .040" ?). Murph's input is probably more worthwile than mine here.

 

[SuperchargedSHOguy]

I would go with a 3" section of pipe and put in a new resonator at that point. What is probably on the car is the dynomax piping - It is 2.5" and pretty nice quality considering the price. However, it will choke off the car up top. I would definitely keep the resonator - it does not hinder flow and makes the car sound a *lot* better. Removing it is a great way to see a lot more rasp and noise. I've never heard a SHO that sounded good without a resonator. Does your car have cats?

If you are planning on a TwEECer and a wideband, I would not worry about hitting the dyno again. If you change the exhaust it would be a good idea jsut to make sure it does not lean the car out too much at high rpms, but aside from that its just bragging rights.

Also, consider having them modify your Y-pipe to have a 3" collector to match the 3" piping if you decide to up the size. That will also help flow (and, subsequently, horsepower) considerably.

The gatorback has a lifetime warranty, but it is probably only to the original purchaser, so you may end up buying one more at some point - However, after that, they're all free. You may also want to look into the Reichard Racing pulley like Lupo has (pictures and a link were posted fairly recently), as they should also eliminate belt slippage and help you hold the boost with less wear on your tensioner and accessory bearings from the extremely tight belt.

With the copper autolites, try running on the small end of the factory gap, or even a little smaller (.042" is the factory minimum - maybe around .040" ?). Murph's input is probably more worthwile than mine here.

I will have to stop by the muffler shop again...I am running a stainless Shoshop catless Y pipe BTW and am raspy as is. I saw those pulleys awhile ago and it is one of my "favorites pages"...another mod I will be doing when I do the twEECer along with a brand new belt. Well then, until the twEECer, 90 MAF, and some other stuff I think we got it covered.

Thanks guys

 

[SHOMurph]

I would try and go around there with the gap. Autolites are inexpensive so I would experiment on what your car likes.

Also get a 3 inch flex pipe.

Gatorback is the only way to go. Anything else will eventually slip.

Pick you up another belt tensioner from a parts car. You'll eventually strip the threads out tightening that mother up!

awwwww forget the resonator and go for flowwwww! The car is already loud..you might as well have fun and set off a few car alarms.

Last if you are running rich add some nitrous.....boost loves nitrous!

 

[AutoSHO]

Last if you are running rich add some nitrous.....boost loves nitrous!

Did your broken pistons tell you that?

 

[SuperchargedSHOguy]

I love nitrous but I love my car more. Maybe after I am tuned , a 50 shot sounds good

Did your broken pistons tell you that?

:laugh_ti:

 

[lightningtroy]

I agree with many of the statements especially those of midwestsho and shomurf. i would def. tune at a lower boot level first. I would not use that "carshow dyno" for much tuning. it probably had not been calibrated since set up and could have affected you're #. i would be interested to know what injectors u use. do u use a fmu? since the spiking occured at peak hp maybe wheelspin was to blame, i have seen this many times especially on well worn dyno rollers. we often put sticky tire on higer hp cars to eliminate this possibility-only a little spin can cause those spikes. as for the dip towards the end maybe you have some clutch slippage it often only occurs at high rpm? just some other poss. to consider. obivously more info would really help narrow down some of you're issues a good dyno with lots of data logging equip would really help and can save a lot of tickets($$$$) from constant testing on the street

 

[SHOMurph]

Did your broken pistons tell you that?

hahhaaha

my broken pistons came after idleing for 10 minutes in the staging area at the local drag strip. Car died....restarted and BOOM!

If I had been spraying it would have made me at least feel better than freakin' idleing!!!

 

[Lupo]

I would try and go around there with the gap. Autolites are inexpensive so I would experiment on what your car likes.

Also get a 3 inch flex pipe.

Gatorback is the only way to go. Anything else will eventually slip.

Pick you up another belt tensioner from a parts car. You'll eventually strip the threads out tightening that mother up!

awwwww forget the resonator and go for flowwwww! The car is already loud..you might as well have fun and set off a few car alarms.

Last if you are running rich add some nitrous.....boost loves nitrous!

Yes, get the 3-inch flex pipe. I like mine.
As far as belt slip goes, I really don't have it anymore. Get one of these babies, and you don't have to tighten the bejeezus out of the belt. Just a little tight...

As far as the dynograph is concerned, is this 15psi with no charge cooling?
After 10psi, because of the Vortech, and the tubing etc, the temps go WAY up.

 

[SHOMurph]

As far as the dynograph is concerned, is this 15psi with no charge cooling?
After 10psi, because of the Vortech, and the tubing etc, the temps go WAY up.

Nitrous is cool!!!

 

[Mike Kopstain]

We've also found that the Napa belts work quite well for an extended period of time. The Gatorbacks are expensive and tend to lose their "supergrippyness" quickly making them no better than any other belt. Try a Napa next time around. You might be surprised.

 

[Sho-Driver]

I have never had a problem with the Gatorback. That combined with the above pulley are a great combination. Gatorbacks are also lifetime warranty so long as you can provide a destroyed belt.