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Discussion Starter · #1 ·
Talked with a engineer who has been with the Viper from the beginning. For legal reasons please do no ask me for his name.

1) Q: Should I pull the O-ring thing out of my brake proporting valve to increase the rear bias?

A: If you track the car, yes, but only if your well seasoned. On the street it is a liability as your rear end will come out MUCH easier. If it rains and you are driving your Snake, you are going to wreck.

2) Q: does the .06 degree's removed from the 00 and up cams really make much differce in HP?

A: No. The only real difference is in the overlap. Any power difference is so nominal it is not worth worrying about. The only reason to put a 96 cam in a 00-02 car is to get your valve overlap back for audio cosmetic purposes only. Very expense for negliable gain.

3)Q: What mods should I do to my 00 ACR?

A: Roller rockers, intake and exhaust, and a VEC1. (careful on the VEC1 as it really need to be tested with a broadband sensor or this really expense computer thingy he hooked up to my car) Other than these just spend the money on learing how to drive the crap out of it.
 

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A VEC1 can be tested and dialed in on a dyno - it's not all that dangerous so I don't understand that one comment there.

Set to full lean on the top end (-20) I still only hit the first and second blue LEDs and I'm not in risk of running too lean.
 

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Discussion Starter · #4 ·
Nexus-6 said:
A VEC1 can be test on a dyno - it's not all that dangerous so I don't understand that one comment there.

Set to full lean on the top end (-20) I still only hit the first and second blue LEDs and I'm not in risk of running too lean.
Yes, I believe he really meant more as a "best practices" way to tune it. You defintally can tune it on a regular dyno.

One other thing that I confirmed is that the computer really does "learn" I thought since it was speed density that there was no way it could learn. He showed me the part of the OEM ECU learing in real time as we tweaked my settings.
 

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Yup - I've heard time and time again that the VEC1 inputs will become "unlearned" over time and that disconnecting the battery to reset it will get things back to good.

Haven't validated this on a dyno over time myself though.
 

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1) Q: Should I pull the O-ring thing out of my brake proporting valve to increase the rear bias?

Why not just buy an adjustable proportion valve?
 

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Was this question asking session a one time deal, or would it be possible for you to ask further questions?
 

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Discussion Starter · #8 ·
He is going to help me on a couple of other issues so yes, I can ask him some other stuff.
 

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brianflynn said:
1) Q: Should I pull the O-ring thing out of my brake proporting valve to increase the rear bias?

Why not just buy an adjustable proportion valve?
Because adj prop valves can only LIMIT the rear bias, not increase it. Pulling the o-ring increases it. And the change might be 10%, so the crap about wrecking is bull.
 

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Discussion Starter · #10 ·
_Mark said:
brianflynn said:
1) Q: Should I pull the O-ring thing out of my brake proporting valve to increase the rear bias?

Why not just buy an adjustable proportion valve?
Because adj prop valves can only LIMIT the rear bias, not increase it. Pulling the o-ring increases it. And the change might be 10%, so the crap about wrecking is bull.
LOL!!! I asked him if I could post this stuff as long as I did not mention his name. He said sure, but whatever you post some "expert" will tell you it's wrong. :lolcry:
 

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Viper said:
_Mark said:
brianflynn said:
1) Q: Should I pull the O-ring thing out of my brake proporting valve to increase the rear bias?

Why not just buy an adjustable proportion valve?
Because adj prop valves can only LIMIT the rear bias, not increase it. Pulling the o-ring increases it. And the change might be 10%, so the crap about wrecking is bull.
LOL!!! I asked him if I could post this stuff as long as I did not mention his name. He said sure, but whatever you post some "expert" will tell you it's wrong. :lolcry:
"Theoretically" mine's out, been out for years, on a daily driver, driven repeatedly in the rain, at least up to 120MPH, and hasn't been a problem. "Theoretically."
 

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Viper said:
LOL!!! I asked him if I could post this stuff as long as I did not mention his name. He said sure, but whatever you post some "expert" will tell you it's wrong. :lolcry:
Yup, there's always an expert. But I speak from experience, not from what I think theoretically would happen. And pulling the o-ring is such a minor adjustment in bias that there's no way you're going to wreck in the rain or otherwise.

Look at the bias change the stoptech upgrade effects, probably 3x the o-ring change, and you don't hear anybody with stoptechs wrecking in the rain.

Nice to have someone "on the inside" to answer questions though.
 

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3)Q: What mods should I do to my 00 ACR?

A: Roller rockers, intake and exhaust, and a VEC1. (careful on the VEC1 as it really need to be tested with a broadband sensor or this really expense computer thingy he hooked up to my car) Other than these just spend the money on learing how to drive the crap out of it.

Sounds good to me; will have T&D's installed next week. :thumb: Just in time for the GAteway test n tune next month.
 

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2) Q: does the .06 degree's removed from the 00 and up cams really make much differce in HP?

A: No. The only real difference is in the overlap. Any power difference is so nominal it is not worth worrying about. The only reason to put a 96 cam in a 00-02 car is to get your valve overlap back for audio cosmetic purposes only. Very expense for negliable gain.

I don't believe this answer either , the lumpy cam cars did much better on the dyno and in the magazine tests , why is that? :idea:cam?
 

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definitely good advice (common sense more than anything) to simply put the seattime in and learn to drive the thing. this is one of the reasons i track and drive the hell out of my car. a couple yrs prior to first mods and now between each stage of mods, whether performance or handling oriented, so i can know every little quirk and shimmy to this sled. (even then ya still gotta be careful or you may get bit /images/graemlins/supergrin.gif)

the viper truly is the "total package" automobile for the car/racing enthusiast.
 

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At the VCA-PVO autocross I asked Herb Helwig about the dinky small rear brakes (I have removed the O-ring, built 38mm diameter rear piston calipers from the OEM 36mm, and now have 40mm rear pistons and it's finally close to ideal.) He stated that it met the legal requirements (meaning never locking the rears.) Maybe the question is what are those legal requirements, and whether that is what kept the brake balance from being as good as it should/coould be.
 
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