Week 1 Impressions of Upgrades

[TexasPettey]

It's been about a week since I got the car back. Here are some thoughts based on the first week of full driving.

Tom's brake upgrade works. The braking is very balanced now. I did a couple of runs through areas I had done before, and the stopping distance was improved. There is some relearning to do, since the rears have more bite than they used to. Once or twice the backs got away from me. I think my first day on the track will be straight line braking only.

The torque from the SC and engine mods is incredible. It's been a blast to hit the throttle and launch. I haven't found there to be any driveability issues, but I've always been gentle on the throttle around town. This will be a real joy on the front straight of TWS.

The exhaust is loud. In the parking garage, I generally get 3-4 car alarms to fire off. There is somewhat of a drone around 1700RPM, but I've learned to avoid it. The only issue will be 6th gear at highway speeds. It's right in the drone zone.

The poly engine mounts were a great move. There is very little additonal vibration in the car, even with the exhaust, engine, cam upgrades. Wheel hop is completely gone. When the tires give way, it is very smooth.

Here's a pic of the engine bay and one of the dyno sheets.

 

[agentf1]

Wow, looks like it will be a lot of fun. Enjoy it and be safe out there.

 

[FE 065]

Congrats ! Back from where..who did the Roe for you?

 

[DAMN YANKEE]

Which psi on the Roe?
What are the full mod specs?

Glad to hear its all coming together.

 

[TexasPettey]

Here are the details on the engine mods. Chris Pharr, a local Viper Tech in Austin, did the install.

http://www4.forum.viperclub.org/showflat.php?Cat=0&Number=798395&an=0&page=3#Post798395

 

[Tom F&L GoR]

Thanks, Chris. Accidental or not, it's nice to be the first comment.

 

[got one]

Boy was that car a beast! Half to tell you, hearing it and going for a ride it...boy oh boy!

 

[viprvenm]

Boy do I remember my first ride when I picked my car up from Roe!

Dave Venski gave me my first ride in my car and I was AMAZED! Very similar #'s too.

Engine bay looks great!

Enjoy and be careful my friend.

Jason

 

[MAVPR]

"There is some relearning to do, since the rears have more bite than they used to. Once or twice the backs got away from me. "


This is the only thing that is stopping me from going with this setup (Toms brake upgrade). Where i live there are no straight roads and sometimes there will be the odd occasion where you will have to brake in a corner. Where as normally the car would understeer in this situation (less dangerous then oversteer in my opinion), I get the feeling with Toms upgrade it would want to oversteer.
Does anyone who has them feel different about this? I would love to hear your opinion on this as this is just my thoughts, I have never driven one with this upgrade.
Thanks

 

[Tom F&L GoR]

Scotland?!

Since I have them, have had them for perhaps the most miles, and have experimented with a few variations, I'll go. There are almost 100 other customers out there and I hope they comment, too. And Nadine was an early adopter- although she designed and built her own set.

New brakes are a re-learning experience. The OEM setup teaches you to drive to the capacity of the front brakes and to gingerly let up when one front wheel locks. You think that's the ultimate, but it's really not. Stock '94 RT/10 went from 0.8 G's to 1.0 G's deceleration with only the brake swap. So your perception of braking changes.

Notice I say brake swap. While the example above was with the 40mm rears, the same improvement will certainly come with any increase in rear brake torque. And obviously a four-piston caliper in the rear will absolutely *require* an adjustable proportioning valve to dial in the brake balance and avoid the oversteer you mention.

That said, about 60% of the 40mm customers have disabled the OEM proportioning valve by removing the spring or the rubber cup seal. (Me, too.) That provides more rear braking under conditions when the prop valve would normally be not allowing it - at the highest pedal pressure, the maximum deceleration rate, and lowest weight on the rear wheels.

Does it cause oversteer? Any tire under load has a slip angle. Asking the rear tire to "turn" and to "brake" within the friction circle means that the tire will slip in both directions. In an autocross this becomes a useful tool for sharper turning around cones. I originally thought the road race customers would leave the proportioning valve alone, but there are just as many track rats that have removed the cup seal.

The end of my story is that any increase in rear brakes will feel much, much different. As you approach the point where all four wheels lock simultaneously, driver preference will dictate the final front to rear bias. And if you want to sneak up on the amount of rear braking that best suits the roads and driving style, you can still install an adjustable proportioning valve with the 40mm brakes, as you would have to do so anyway with 4-piston calipers in the back.

Sorry to hijack or be pushy. I just think the OEM setup is really pretty mediocre and however you improve it, please do.

PS: Dave and I have an international "special" so you don't have to return the cores. Dave's Big Brakes

 

[MAVPR]

Thank you for all that information, I am actually going to see Nadine this weekend so i will pick her brain for information

"international special" Could you pm me with the price for that?

I just realized I my have hijacked this thread without even noticing (SORRY) but if people wouldn’t mind giving me there views on this it would really help me to make my mind up.
Thanks

 

[Steve 00RT/10]

This will be my 3rd season with Tom's brake upgrade. I removed the prop valve early on and have had no issues. My right front will still lock first--at least in a straight line. I get on a track about once a year and actually wore out my rear pads before the fronts on the last set. ...Couple autocrosses in there as well. I'm quite pleased with the upgrade. As a side note, I opted to leave the B3s on all the time (instead of switching to 'dustless pads' as I used to). The pedal feel is different between different pads and I feel I can get better at finding the threshhold by running the same pads all the time. Safer for the street as well.

Steve

 

[Tom F&L GoR]

It's not that special, just $999 for 40mm calipers and you dont' have to return your old cores. Saves shipping one time across the ocean.