About 14% in your case, which is right in line with what most say the difference is from Mustang and Dyno.

So, like I said his pwr is right on, just an issue of the Mustang.

 

The shop Mike used very experienced when it comes to 951's and when I help Mike drop off his car I bs'ed with him for about an hour about his dyno setup and tuning 951. Really seemed to know what he is doing and showed me his own personal car running 300+ hp with a custom chip he burned. I am pretty surprised that he seems so far off on this tune.

Mike - I'm not sure if it is worth going back to Chris and getting him to fix it for free, but you may want to check out Backstreet Dyno. I went with Dan P to get his Mafterburner and Lindsey S65 tuned by them and was very impresed. He worked with Dan for almost 2 hours and charged him only a little over $100. He also was able to get the fuel curve as flat as the software would let him (quite a bit more than yours) and was bitching that the Mafterburner didn't have enough resolution and that he liked the SMT6 much more because it had better resolution. Over all I was vrey impressed with their knowledge of the various piggybacks and stand-alones - although Chris seemed to know his **** as well.

BTW - what mods do you have again ; ' )

 

Hey Skip, check the other post, like 28. I put all my mods in there. I might take it to Backstreet as well just see what is puts down on a dynojet. I know a couple other guys are going there next month. I sent John a datalog I just took to see what is up. Chris did seem like he knew a lot about the cars, that is why I was a little surprised to see my car dynoed at 240rwhp, when just 2 summers ago that is EXACTLY what I put down on a dynojet. I will say it pulls harder then before, no question about that! You, Dan P, and I should grab some lunch sometime and see what you guys think.

 

I also agree about the Mustang dyno reading low. I have had my car on 3 different types of dyno's (Mustang, Dynojet, Dyno Dynamics) and the Mustang reads the lowest by far, with over 50 rwhp spread from highest to lowest. You simply cannot compare numbers from different dyno's, even though people want to do that all the time. The dyno is a great tuning tool if you stick with the SAME dyno and look for changes. The actual numbers are just estimates of "real" hp and torque.

 

Mike, I reviewed your log file.
(a) there was no modification to the ignition.
(b) the map was richened up a bit more than I have seen before, something isn't up to the task.

- How old is your fuel pump?
- Is the vacuum line to the fuel pressure regulator fine (no leaks)?
- How old is your DME relay?
- Did anyone watch the fuel pressure while on the dyno?
- Is the BOV holding boost?

 

My fuel pump is about 2 years old.
All my vacuum lines are good, just checked that one to fuel reg, looks good. I put zip ties on the ends of them as well so they don't come off.
DME relay is like 2 years old, it is a 993 one. I have the stock one from the car as a spare.
I don't think they watched the fuel pressure at all.
I have the Forge BOV that is 3 years old, it seems to hold boost just fine, never gave a problem before. Is there a certain way to check for it?

 

push in the piston and hold your finger on the nipple, and see if the piston closes

 

Ok, so push the piston all the way closed/opened, then block off the nipple so no air can go though, then let go of the piston. What should the piston do then?

 

You just have to push it open somewhat and cover the nipple on top with your finger. The piston should stay where you pushed it to. If it goes back down into its seat it is not holding a vacuum and should be replaced / looked at.

 

Heya Mike, I've been watching this thread with interest, but my lack of a contribution is exactly because I don't have much to contribute. Like the rest, it is easy to blame the dyno differences for a big part of it. You won't know until you are on a like dyno in similar conditions. Just because my car put down relatively big numbers does not mean I know how I got there. Yes, I did a lot of work myself but I left the tuning to guys who know, as it seems you are doing too. Cuz has stumbled thru a tuning hell, and had other issues on top of it. From clocking the MAF to MAFterburner tweaking, I've been shooting in the dark. Regrettably, I don't have any experience with anything Vitesse, but I've heard a ton of great reviews. Anyway, the bottom line is I can't help you with much. It sounds like you do have the right people on the case. If it any consolation, one of my favorite sayings is "Beware what you wish for, you just might get it". I dreamt of 400WHP, and now that I spent considerable ching to get there, I find myself looking at it and going "WTF am I going to do with this NOW?". Much over 300 WHP is not really needed on most tracks, street racing is very UN-PC, and the faster it gets the less drivable it seems to get. As for a lunch, my new routine has a gorgeous and fun 4 year old attached to my hip (which is very cool) and me moving my large pile of worldly possessions to a sweet new house. Jetting your way for a lunch is not likely to work out, as much as I would like to. If you find yourself up this way on a M, T, or Wed, give me a couple of days notice and I could meet up with you, or show you the new digs. If I'd known you and the Skiperator were at Chris' I certainly would have tried to come out for that. If it is not obvious from my OT banter, I've experienced a considerable priority shift.

Your package is on the way.

Also, Congrats, and watch your back out there, Officer!!!

 

Yep, driving a high powered turbo car at the limits takes timing, skill, and lots of practice. You have to anticipate getting into throttle and how much to apply. Much past stock and it ain't just mash and go any more.

 

Well, I checked the BOV and it holds pressure John. I am getting a gauge to test the fuel rail/fuel reg, as well as checking the pump as well. I installed the BOSCH "HV" FUEL PUMP 944 / 951Code: LR951-BOSCH-FP one about 3 years ago. I should have got the Bosch "044" pump after reading everything about it now. Has anyone used the pump I have, if so, how is it working for you?

 

Mike, replace the DME relay. I have seen them latch/unlatch quickly where the fuel pump is ON/OFF quick enough, it feels as a slight ignition miss.
The BOV could be opening at a certain boost, then closing when the pressure drops.

The fuel pressure must be monitored under load, if there is a drop the fuel pump is suspect. If the fuel pressure is fine, I would test the BOV on a bench at the same boost pressure.

 

Hmm, so I would have to take the car to the dyno put a load on it then see what the fuel pressure is then. I have two DME relays, the one that I had when I bought the car, so who knows how old that is, and a 993 one that is 3.5 years old. I will switch that out to the old one (I run the 993 one normally) and see if that makes a difference.
When I was driving my car today I noticed that after my car gets hot (driving for like 30 mins or more in 85 heat) that my guage for air/fuel seems to go REALLY lean then it stumbs on idle. If I give it just a little bit of gas, it goes, but then when it goes back to idle it will do it again. I checked the idle and it is fine.

 

Mike, you need to identify the components that are affected by heat. It sounds that you have various problems that may or may not be related.

Heat will affect the fuel pump, a TPS can be affected by heat where it no longer signals the correct state. A failing DME can act differentlu if hot (I doubt it here)...

I would start by making a list of the issues, document the conditions under which you can trigger them. Once you know what it takes to cause a abnormal condition, you will have to check all of the related components at the time of the failure.
This can be time consuming. Too bad you are not close, I can install the Motronic Monitor on your car and view all of the sensors and data as seen at the time of the failure..

Good luck.