To Dyno or not...

[jonathancasey19]

Well the big Rudy's Diesel Challenge is here this weekend in NC. I'm having a hard time deciding if I want to hit the rollers. Last time I dynoed was in 2008 with stock turbo & fuel system. Since then, I have a gt4088r, 45% over injectors, and a 120% stage 3 cp3 with 193,xxx miles. I'd really hope to put down a low 600 but who knows. The thought of watching my truck blow up in front of me is a little scary..... . I guess it's less hard on parts than drag racing? Would dynoing with 35's and 20" rims lose power as opposed to running stock rims and 285's?

Thanks

 

[SSchmi5519]

Well the big Rudy's Diesel Challenge is here this weekend in NC. I'm having a hard time deciding if I want to hit the rollers. Last time I dynoed was in 2008 with stock turbo & fuel system. Since then, I have a gt4088r, 45% over injectors, and a 120% stage 3 cp3 with 193,xxx miles. I'd really hope to put down a low 600 but who knows. The thought of watching my truck blow up in front of me is a little scary..... . I guess it's less hard on parts than drag racing? Would dynoing with 35's and 20" rims lose power as opposed to running stock rims and 285's?

Thanks

Ok.

Yes better power with the 285s.

Yes it is less stress than making a pass. (Given same RPM...don't take it to 4800 on the dyno haha)

Yes it is scary making pulls on any modded CP3 system and stock bottom end.

 

[arneson]

Id dyno it. If u drive around everyday with the set up whats a few10-15sec pulls? As for the tires/wheel combo it maybe a touch lower due to rotating mass but wont be crazy. May people dyno/ race with 20s and big tires. If it was me id throw stockers on tho.

 

[SSchmi5519]

Id dyno it. If u drive around everyday with the set up whats a few10-15sec pulls? As for the tires/wheel combo it maybe a touch lower due to rotating mass but wont be crazy. May people dyno/ race with 20s and big tires. If it was me id throw stockers on tho.

We race on the big tires more for traction/larger footprint, especially here in the southwest where the tracks are always dusty/dirty.

It wont help you on the rollers unless you are spinning on the rollers, which I have seen happen with 245s ~640rwhp.

 

[super diesel]

If you have pushed it on the street or track at any time and it didn't blow up, you should be fine on the rollers. If it's going to compact the rods, it's already done it on the street or track if you've run it any in the big mode.

 

[PureHybrid]

Im with these guys, dyno it! If it blows up, at least you know it went kaboom at XXX amount of power

 

[jonathancasey19]

80 bucks to dyno is rediculous. I recon ill see what it has. Hope I dont lose too much power on the larger tires and rims.

 

[Chevy1925]

ive tried different sized tires on a dyno, made no difference and thats going from 37s to 245s. i still only made 445hp way back when. only thing i noticed was 2psi less in boost on a stock charger

 

[dmax711]

I was going to go to this too, but decided not to just gonna hit z max in a few weeks and see what she can do there..

 

[MACKIN]

$80 bucks how many pulls? If it's a single ya that is pricey. If it's at least 3 that is about the rate that I recall. Between hook up this and that ,that equals about a half hour or more on the dyno.

What type of dyno? Load cell or inertia dyno?

 

[jonathancasey19]

It's a dynojet so I believe it's an inertia dyno. Am I correct saying you can't load it correctly to the vehicle weight; thus, skewing the results? And yes it is for three pulls. My biggest tune is a 2450 pulse. I'll try to add more fuel on the second pull to see if it makes a difference.

 

[super diesel]

I'm with James. I would think that the bigger tires will help load the turbo on the dynojet. Good luck. I'm sure you'll be fine. If your worried about it, take a compression test before going to the dyno to know where your at. You should be up around 400psi on you cylinders with stock pistons. However you will still dyno well with it around 300 or less psi with bent rods. My friend has been running with them this way since 05.

 

[GeneralTJI]

I guess it's less hard on parts than drag racing?

How many gears and you planning on running through WOT on the dyno

 

[othrgrl]

There are different models of DynoJets, both inertia and load cell. On inertia dynos bigger tires and heavier rims can sometimes help you out because the extra load will help get the charger to act more like it does with the weight of the truck on the street. On load cell dynos it will typically hurt power a little having bigger tires. Very aggressive mud tires with spaced out lugs, especially in line (Mud Grapplers, M16s, boggers, Crushers, etc) can really hurt power - bouncing lug to lug seems to throw off the dyno.

 

[super diesel]

^^^^Also what Dustin said. The DynoJets I've been on were all inertia (I presumed this is what it would be). The load cells I've been on were Mustangs and SuperFlows (SF is my favorite). Thanks for clarifying.

 

[MACKIN]

If it's a Dyno-Jet go with the bigger tires and have at it. There isn't much of a load as compared to a sweep on a Super Flow. Run the bigger OD tires also

 

[arneson]

$80 for 3 pulls? Thats a deal. Minimum of $125 for 3 pulls by me. But sure be sweet to see what your upgrades have done.

 

[MarkBroviak]

Go for it buddy! If it lets go on the dyno it was going to let go the next time you stepped on the skinny pedal anyways.:thumb: