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Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 2:19 am
by Desertjr
I saw it kicked around here in the past where people have tested different cams for power band and such. Does anyone still have one? I would gladly pay for your time if you wanted to run some things for me on a stock 4.0 setup. Basically just cams.

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 3:47 am
by Desertjr
double post

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 3:49 am
by Desertjr
Ended up buying it myself. Now I need to get the stock 4.0 specs all correct so I can start testing changes. I'd be willing to help anyone who after I get this thing setup correctly. I've tryed myself a few times but seem unsuccessful!


Whats our manifold type? Using the 99+ style if it matters. (tuned port? single plane? Dual plane? ect)

How far in inches is the piston at TDC on the stock 4.0? I'm guess how far down in the hole? I tryed using .0215 but it only gives me from .100" - 2.0"

And what about volume above piston is cc's?


I've got most of the stock specs in and I'm only getting 99hp @ 5500rpm and 104 ftlbs. @ 4500rpm :doh:

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 4:36 am
by Cheromaniac
I've been using Dyno 2000 for many years so I've had endless fun playing around with engine specs. Now you know why I recommended the CompCams 68-231-4 cam for your 4.2L mini-stroker.
The intake manifold is tuned port injection.

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 5:09 am
by W_A_Watson_II
I've got the Dyno2003 by ProTools (Motion Software V4.05), but never quite figured out how to get all the specifications in and correct for my Stroker.

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 9:51 am
by IH 392
I've also got the "DYNO 2000" version, my computer had a meltdown last year and I lost all f my simulations :frustrated: I haven't gone back and redone them, like Dino says, it's great for playing around, tweaking this or that! :cheers:

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 1:28 pm
by Desertjr
I'm trying to get mine all set up..gonna get back at it right now. Gotta get it set up for a stock 4.0 is anyone can help with that?

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 1:59 pm
by Desertjr
Dino using your cam spread sheet. Whats the specs listed at?

.050" lift or seat to seat? The dyno sim. when the cam specs are @ seat-seat give 158hp @ 4500rpm 208ftlbs@3000-3500rpm. Stays steady.
All specs are stock. Head flow converted from 209cfm @ 28H20 to [email protected].


My specs inputted are giving this.
Power Torque
2000: 75 197
2500: 97 203
3000: 119 208
3500: 138 208
4000: 152 200
4500: 158 184
5000: 157 165
5500: 147 141
6000: 129 113

Re: Does anyone have a "desk top dyno"?

Posted: February 23rd, 2013, 2:43 pm
by Desertjr
After playing for a few I found out a few specs I like better than the stock comp 231 has to offer.

108 intake centerline
110LSA
250* intake duration
260* exhaust duration
.482" intake lift
.492" exhaust lift

17 IVO (BTDC)
53 IVC (ABDC)
64 EVO (BBDC)
16 EVC (ATDC)


Dino think you can run that for me vs the comp 231?

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 1:07 am
by Desertjr
And playing around some more. The mopar P4529229 beats the comp 231 & the "modified comp 231" I was playing with. It also does so at much much less lift!

This arent accurate obviously but it does show a damn clear difference.

Comp 231 off the shelf
Power Torque
2000: 99 259
2500: 122 257
3000: 144 251
3500: 154 231
4000: 155 203
4500: 142 165
5000: 118 124
5500: 88 84
6000: 52 46


Mopar P4529229

Power Torque
2000: 101 266
2500: 124 260
3000: 149 260
3500: 164 246
4000: 171 224
4500: 166 193
5000: 150 158
5500: 127 121
6000: 96 84


Again the motor portion was as close as it would allow me to get to a stock 4.0. Its not perfect by any means but it works for showing cam differences! I then changed the bore to 3.935, stroke to 3.500, compression at 9.3:1. Then run with my 1.95/1.54 valves through a stock flow 4.0 7120 cast head. (178.1cfm @1.5inHg). Then plugged in the comp 231, then played with the Mopars that are no longer offered, 505, Hescos RVOB6, comp 232, modified(my specs) 231. Mad since the 30ab from mopar was no longer offered and was my favorite, I decided to drop the P4529229 specs in. It beats all the other cams I tryed where I want power at! Dino can you help me comfirm this? Not only did the P4529229 make more power & torque where I want it, it does so at .440" lift vs .462/.485 of the comp 231. Dino can you confirm for me, or anyone else with the desktop dyno that the P4529229 beats out the comp231 everywhere? It seems to be the "go to" cam but this proves differently? Unless theres another reason to not run the Mopar?

Also is running the P4529229 safe on stock valve springs? Or should aftermarket springs be run, I'm leaning aftermarket because how close it is? If aftermarket, then what seat pressure & open pressure should I be looking for? I have to grind the seat either way since I'm running a ls6 valves. I know to high of pressures usually equals or help contribute to a cam failure, so if I can get a range to be in, then we can deffinetly make it happen!

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 4:49 am
by Cheromaniac
Desertjr wrote:.050" lift or seat to seat? The dyno sim. when the cam specs are @ seat-seat give 158hp @ 4500rpm 208ftlbs @ 3000-3500rpm. Stays steady.
All specs are stock. Head flow converted from 209cfm @ 28H20 to [email protected].
Try inputting the head flow numbers from my site (209cfm) @ 25H2O, and use the 0.050" lift duration numbers from my spreadsheet for the cam specs. You'll get very different results.

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 5:26 am
by ruffy01
I found a link & downloaded Desktop Dyno 2003 only a few weeks ago.
It was a free version versus a Pro Version but works great :D
I've been getting some good numbers, nice curves, from the 505 Performance cams.

Any negative feedback on their cam's?

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 5:50 am
by SilverXJ
Everything I have heard about 505 parts and service has been negative.

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 6:56 am
by Retlaw01XJ
ruffy01 wrote:I found a link & downloaded Desktop Dyno 2003 only a few weeks ago.
It was a free version versus a Pro Version but works great :D
For anyone else looking for a download of Dyno 2003, go here and scroll down to 'software':
http://loco4fomoco.com/video.html

I haven't been able to find a jeep 4.0 engine file, anyone have it? I had to build a file up from a Mopar slant six, as it's one of the few straight six files available.

Re: Does anyone have a "desk top dyno"?

Posted: February 24th, 2013, 8:58 am
by 5-90
Desertjr wrote:Ended up buying it myself. Now I need to get the stock 4.0 specs all correct so I can start testing changes. I'd be willing to help anyone who after I get this thing setup correctly. I've tryed myself a few times but seem unsuccessful!


Whats our manifold type? Using the 99+ style if it matters. (tuned port? single plane? Dual plane? ect)

How far in inches is the piston at TDC on the stock 4.0? I'm guess how far down in the hole? I tryed using .0215 but it only gives me from .100" - 2.0"

And what about volume above piston is cc's?


I've got most of the stock specs in and I'm only getting 99hp @ 5500rpm and 104 ftlbs. @ 4500rpm :doh:
Go sign up for my JeepPower group - there should be data files for Dyno2000, and Excel sheets or .pdf files detailing individual specs (if not, I can look them up in my reference copy of the _Power Manual_. I probably don't have everything, but I've got most of it!)

DUH - forgot the link. groups.yahoo.com/group/JeepPower.