Dyno'd with the Paxton

[crazyfast]

I've got some A/F reading discrepencies between my LM1 wide band and the dyno shops A/F numbers.

On my LM-1, I saw 11.2 coming in at 3400 rpm and it climbed to 11.8 by 6000 rpm

The dyno showed totally different numbers.

I'm not sure which machine I should believe. This dyno has shown accurate A/F numbers in the past and with the lower HP/TQ numbers shown in the graph I'm thinking the dyno might be right.

This car has headers, no cats and side exit exhaust. I'm running the bigger disc in the FCU and sent the computer to DC for a conservative tune.

What do you guys think?

 

[plumcrazy]

where was the dyno taking readings from ? the tailpipe or a **** in the header/exhaust ?

 

[Finally got it !]

where was the dyno taking readings from ? the tailpipe or a **** in the header/exhaust ?

 

[crazyfast]

LM1 was in a **** just after the header.

Dyno was at the end of the tail pipe.

 

[Joseph Dell]

you are very, very rich. that car has a ton more power if you can get a reflash or tune it. the a/f should be 11.5:1 or 12.0:1 for optimum power. 10.5:1 or less and you are wasting fuel AND robbing power.

JD

 

[proggod]

Did you calibrate your lm1, or for that matter the dyno sensors. LM1s tend to go bad over time, however the innovative stuff lets you calibrate around that.

 

[crazyfast]

Joeseph I agree. But I'm not sure if these dyno numbers are accurate or not as far as the AF goes.

PRO yes I calibrated the LM1 and it's brand new....the dyno just slide the sensor into the tail pipe, didn't see any sort of calibration going on there.

I'm going to have to get a third opinion on the A/F numbers.

 

[crazyfast]

Got a 10am appointment tomorrow at DC Performance for some dyno tuning.

 

[crazyfast]

So I went to DC Performance today. What a cool shop, Chris, Lyle and Dan are pretty cool guys and they know their stuff too. I'd really like to thank these guys for getting me in with such short notice...there are a lot of Vipers in this shop.

So Chris did some tuning on the car. He took care of the leanness in the lower RPMs and flatend the the A/F ratio and he found something else.

Can anyone tell whats wrong with this picture?

Dan even bought me lunch

 

[crazyfast]

Also we again had some differences in the A/F readings. You can see the readings DC's dyno pulled in the graph above. With the LM1 I did some more data logging and it shows the A/F starting out at 11.1 and it holds right at 11.1 all the way to 6000rpm.

 

[Tusc]

One thing I am NOT is a tuner.... but either the blower belt was loose or something funky like a bad map sensor or loose plug wire was skipping you around.

Impressive numbers all the same.

I know I'm wrong, so spill the beans.

 

[proggod]

My supercharger was all f*'d up, dc performance fixed it right up. Although performance ***** in the 100+ weather we have going right now, can't wait till it gets cooler

 

[crazyfast]

One thing I am NOT is a tuner.... but either the blower belt was loose or something funky like a bad map sensor or loose plug wire was skipping you around.

Impressive numbers all the same.

I know I'm wrong, so spill the beans.

Loose belt was a good answer. Unfortunatly it's self tensioning...so I have to do some re-engineering....or try to find a slightly smaller/better belt. I'm looking into a few things. Last resort is teh DLM tensioner.

The numbers are nice considering the shortage of boost. Another pound and a half or so should do some good things.

 

[Tusc]

So your reasoning is that if the existing tensioner system is having problems, then a smaller belt with less rotating mass and surface area might work better? Because I'm used to people solving the problem by going in the opposite direction and going wider for more footprint. Lateral space must be an issue?

Kind of a dumb/geeky question.... but how many pounds of pressure can the belts and pulleys take? Does the manufacturer have data on this or some guidance? Would it be possible to take the existing tensioner from the kit and refit it with a stronger spring? I've never taken one apart to look. You obviously can't load it up too much for fear of ripping apart your accessory area or the back of the radiator, but if it's something that can be fixed by going from say 15lb to 17lb, it's the sort of thing I'd be all for.

I don't have any answers for you on this one, but good luck. I'm curious to learn what works in the end.

Edit: Though if DC already has a part which they know will work... it usually saves headaches in the long run to **** it up and rip it all apart to put the right piece in for a few extra bucks. Oddly enough, it's been my experience that this is often cheaper than trying to circumvent problems on my own. LOL (Though I do so enjoy putting my mind to a problem.)

 

[Dave T(BADVENM)]

I was gonna say the boost numbers seem low and should be building with a peak at redline.

 

[MikeR]

Wow, it does look like your loosing some Boost. With the extra 1- 1/2 lbs, I'd figure you should hit 700 rwhp. Good numbers. And I've heard good things on the DLM tensioner. I plan on using some of his stuff on my setup in the works.
What are are you in, id like to check it out, i figure california , if ou went to DC. Anyways, I saw your install pics. I will be using them as guides when I do my install.

 

[crazyfast]

So your reasoning is that if the existing tensioner system is having problems, then a smaller belt with less rotating mass and surface area might work better? Because I'm used to people solving the problem by going in the opposite direction and going wider for more footprint. Lateral space must be an issue?

By "smaller" I ment smaller in circumference....this system needs all the surface area you can give it. There is a 10 rib pulley system but there is not enough room for it. Doug Levin has the adjustable tensioner.

Kind of a dumb/geeky question.... but how many pounds of pressure can the belts and pulleys take? Does the manufacturer have data on this or some guidance? Would it be possible to take the existing tensioner from the kit and refit it with a stronger spring? I've never taken one apart to look. You obviously can't load it up too much for fear of ripping apart your accessory area or the back of the radiator, but if it's something that can be fixed by going from say 15lb to 17lb, it's the sort of thing I'd be all for.

I don't have any answers for you on this one, but good luck. I'm curious to learn what works in the end.

Thanks, that is an idea...I didn't examine the tensioner that closely so I don't know if this is a feasible solution. The DLM tensioner is manually tightend.

I was gonna say the boost numbers seem low and should be building with a peak at redline.

yeah...I'm really curious as to how much power this thing is actually going to put down once I have all the wrinkles ironed out.

 

[Dave T(BADVENM)]

I reached 667 rwhp on my Paxton 8 psi setup with my SRT Ram after Joe Donovan of PBJ added a VEC3 and his masterful tuning skills. With water/**** we hit 702 rwhp.

Have you driven yours after the tune? Did DC Performance add a blower flash to yours? It really helped out my truck when I added it.

 

[crazyfast]

I reached 667 rwhp on my Paxton 8 psi setup with my SRT Ram after Joe Donovan of PBJ added a VEC3 and his masterful tuning skills. With water/**** we hit 702 rwhp.

Have you driven yours after the tune? Did DC Performance add a blower flash to yours? It really helped out my truck when I added it.

Yes it has the DC Performance blower flash. I sent my PCM to them for the tune. Today I brought the car down to their shop and Chris fine tuned it even further. The car runs great,

I expect to see something between 650 and 700 rwhp.

 

[plumcrazy]

DLM tensioner !!!

 

[Y2K5SRT]

There is a 10 rib pulley system but there is not enough room for it.

Are you sure about that?

 

[crazyfast]

Pretty sure it wont just go in.



That its the best option for this problem...it comes with a lot of components and of course it cost more....also according to Doug Levin would be over kill for my application. I've got one of his mechanical tensioners on the way.

Are you sure about that?

 

[Y2K5SRT]

according to Doug Levin would be over kill for my application. I've got one of his mechanical tensioners on the way.

I will never disagree with what Doug says in a million years. Glad to see you have one of his tensioners on the way too. Paxton builds an incredible set up for the Vipers - Doug just happens to take the Paxton performance to the next level.

Be sure to let us know how the tensioner does!

 

[Joseph Dell]

Pretty sure it wont just go in.

Count the ribs and check the part # on the belt. a 10 rib fits quite well. And that is THE ticket for the paxton set-up.

nothing wrong w/ the 8-rib... but you'll get more belt wrap and be able to support more steady, predictable boost with a 10-rib.

JD

 

[crazyfast]

Count the ribs and check the part # on the belt. a 10 rib fits quite well. And that is THE ticket for the paxton set-up.

nothing wrong w/ the 8-rib... but you'll get more belt wrap and be able to support more steady, predictable boost with a 10-rib.

JD

Joseph, in my research I've found the 10 rib requires replacing the S/C pully, tensioner and the crank pully along with some other items correct? DLM sells a 10 rib kit for SRT's, it comes with a price tag around $3,600.00 is this what you are refering to or do you have another way to get the 10 rib in there?

I appreciate your input on this.

The mechanical tensioner for the 8 rib belt is $250.00 and I bought a Good Year Gatorback belt to replace the original paxton belt....the rubber on the new belt feels more "grippy". I figured I'd go this route before making the jump to the big boy stuff.

 

[Joseph Dell]

Joseph, in my research I've found the 10 rib requires replacing the S/C pully, tensioner and the crank pully along with some other items correct? DLM sells a 10 rib kit for SRT's, it comes with a price tag around $3,600.00 is this what you are refering to or do you have another way to get the 10 rib in there?

I appreciate your input on this.

The mechanical tensioner for the 8 rib belt is $250.00 and I bought a Good Year Gatorback belt to replace the original paxton belt....the rubber on the new belt feels more "grippy". I figured I'd go this route before making the jump to the big boy stuff.

that sounds a little steep. PM me and we can discuss.

 

[Doug Supercharged Vipers]

that sounds a little steep. PM me and we can discuss.

Hi Joe!

It certainly is steep but it's a proven system - enough to hold 1000+ hp! The DLM 10 rib pulley system comes with an entailed list of parts - your replacing the factory water pump, pulleys, brackets, supports, tensioner etc...

.... and when your done attempting to duplicate it and find yourself loosing belts, horsepower, blower seals, and trying to make it work the $3,600 dollar price tag is not such a bad deal. We sell A LOT of systems to those who attempt this project.

It's a limited market but if we sold more of them we could significantly drop the price - and it WILL happen; we're working on it now

Best regards and thanks for reading!
Doug