Horrible Dyno Test

[Dave_F]

This morning, with 600+ miles on my 2003, I made a trip to one of Viper shops here in Houston. My car is part of the valve recall, and the results showed. The first run was 378 HP and 429 torque, which are disappointing numbers and certainly lower that I would have expected, even with the valve issue. However, the second run was really weird. At 4,500 RPM, the HP was still below 250, and the dyno operator stopped the run early. These numbers were showing almost 100 HP less than the first run. The shape of the HP curve on the first run was jagged, and the second run was almost a ZIG-ZAG. The second run seems to signal a serious problem to me.

I'd bet that the guy doing the testing is one of the most experienced Viper techs in the country, and he said "I never seen a Viper do this!" He also stated that he would mention it to Charlie (the Dodge engineer I think) the next time that they talk.

I'm planning to do the recall, and I have spoken to the dealer that will be doing the work. I think parts are supposed to be available after May 26th.

What would you guys do next? What do you think?

Comments / questions / advice appreciated.
Thanks

 

[AJT]

Where did you Dyno it?

Andy

 

[Joseph Houss]

Dave,

This is NOT a valve issue (only 25HP differential maximum can be expected from the valve issue). There has to be something else wrong... whether it be the dyno itself, or an additional issue unrelated to the valve issue.

Surely take it to your Viper Tech immediately, and let him scope things out.

 

[GR8_ASP]

So far every posted dyno curve shows the jagged shape. Never saw anything like it. It isn't the dynos as in back to back tests with Gen I/II the Gen I/II curves were normal. I am putting mine on a dyno next Saturday. If it is strange as well I will give the results to PVO and ask what gives. Has to be some reason, either engine or driveline, to cause this.

I have also noted very different performances out of mine. I attributed it to temperature as the day it performed sub-par was warmer than any other day I have driven it. Note I also have the valve issue.

 

[Dave_F]

I had the testing done at RSI and my friend tested his 2000 GTS immediately before my 2003 and produced 399 HP. He has smooth tubes and a Corsa exhaust as his modifications.

I'm very frustrated that not only do I have a valve problem, but something more, something still unknown.

Dave

 

[Newport Viper]

This is why I never buy the first year of ANY car. Too much stress!!!!!!!!!!!

 

[SnakeBitten]

2000 GTS produced 399 HP. He has smooth tubes and a Corsa exhaust as his modifications.
Dave

Thats pretty low too with those mods...

 

[GR8_ASP]

Yes, to dyno an SRT at 20 hp below a Gen II is indicating more than the stated 20 hp loss. I will find mine out this Saturday. Now what do you do if you are down on power without an identifiable defect?

 

[Y2K5SRT]

This is why I never buy the first year of ANY car. Too much stress!!!!!!!!!!!

I bought my 2000 GTS knowing it was not the first year production car and it still had problems, as did numerous other 2000's that required a complete motor rebuild. Bottom line: NO car is perfect and no year is perfect either. Besides the obvious valve problems (which was a supplier problem that could have occurred in ANY year), I think the SRT has been remarkably trouble-free. Indeed, the SRT survived the recent Motor Trend tests without incident, while I recall a 1998(?) GTS couldn't finish the top-speed test as it blew a hose and overheated.

Every year will have its problems - please try not to group every other 2003 with these isolated instances...

Chris

 

[Torquemonster]

well - I'm sure this has been well and truly sorted out by people much more qualified to do so - but it sounds like valve springs.... they may handle the stock rpm's ok, but if the roller ramps are too steep for the spring, it might bounce thru the rpm range - and that would cause intermitant power spikes and dips as the springs worked and didn't as the case may be....

just an idea... I'd be surprised if you had bad springs on a factory car... but it's worth mentioning....

otherwise it's likely to be ECU related. Power should be smooth, jagged normally means detonation... I said "normally" - didn't say that was what it was... but I'd be checking that too - to know for sure. Good luck!

 

[George Murray]

Sounds like they slipped the little-known turbo-diesel option into your car!

 

[Craig 201 MPH]

wouldn't it seem like the dyno is screwed up? for a GTS to throw down 399 h.p. is pretty weak as well as your numbers. I guess you could tell if you took it to a strip and saw what MPH you could pull off in the 1/4.

 

[Viperfreak2]

If the jagged hp curve is NOT related to the intake valve issue, then why did we see so many SRT's reporting strange dyno results BEFORE Dodge reported the problem??

 

[RC Viper]

My SRT had the jagged edge dyno. We noticed this BEFORE the announcement of
the valve issue. In fact, when the dyno operator saw the graph he suggested to me that "something was wrong with my car". Not to mention that it only did 425 HP with a K&N upgrade.

 

[Lawrenzo]

[quote
while I recall a 1998(?) GTS couldn't finish the top-speed test as it blew a hose and overheated.



[/QUOTE]

If my memory serves me correctly, that was an owners car with around 15 or 20,000 miles on the clock. And it still did 192mph beating everything else out there!!!

 

[DEVILDOG]

[quote
while I recall a 1998(?) GTS couldn't finish the top-speed test as it blew a hose and overheated.

If my memory serves me correctly, that was an owners car with around 15 or 20,000 miles on the clock. And it still did 192mph beating everything else out there!!!

[/QUOTE]

You are correct. Motor Trend May '98. The speed was 192.6 and was the fastest production car they had ever tested and it finished the high speed test before blowing a water pump gasket. Motor Trend stated " admittedly, the car had 11,000 abusive journalist miles on it as delivered, equivalent to 44,000 quarter-mile runs-which may not be too far from the truth ". An SRT won't even run that fast so don't knock our '98s. Sounds like those SRT single beehive valve springs may not be doing the job!