Kudos to 40 mm rear calipers

[ViperRay]

I put Tom Hayden's 40 mm rear calipers on the GTS and have run them for two track weekends now. What a huge improvement!

I have Brakeman 3's all around. After two weekends, I checked the pads figuring to replace the fronts and found that the rears also were done! I put on all 4 at the same time. At no time did I lock the rears.

This setup (in conjunction with removing the rear prop. valve) definitely improves the braking balance. I can't compare it to StopTechs but, then again, this mod doesn't cost thousands!

 

[AG98RT10]

Yep, I ran Tom's 40MM at Viperdays and never locked the fronts or flat-spotted - great feel with Brakeman 3's. This is one of those best-kept secrets of the early Gen II's. Brakes like an entirely different car.
I kept the stock proportioning valve in. Have you noticed any tendency for rears to lock first with it out? I May have to experiment next year.

 

[ERDOC]

I agree! Installed the new 40's on my GTS with much improved stopping ability. Significantly improved threshold to the point of lockup.

 

[ViperRay]

AG,
I have not noticed any tendency for the rears to lock with the prop valve removed.

 

[Chuck 98 RT/10]

I've been wondering about Tom's setup. Good to hear that it doing the job.

 

[PhoenixGTS]

This is one of those best-kept secrets of the early Gen II's. Brakes like an entirely different car.

Throw a noob a bone here. Are you saying these 40mm calipers are OEM on early Gen IIs and you put them on your Gen Is for an improvement? Wait that can't be it since you have a Gen II.

 

[AG98RT10]

This is one of those best-kept secrets of the early Gen II's. Brakes like an entirely different car.

Throw a noob a bone here. Are you saying these 40mm calipers are OEM on early Gen IIs and you put them on your Gen Is for an improvement? Wait that can't be it since you have a Gen II.

No, they are bored out stock rear calipers that effectively shift more of the brake proportion to the rear (by leaving the fronts unchanged). There's a thread around here somewhere that explains everyhing - have to look for it for ya. The reference to Gen II was just that the brakes on the early models are the same as Gen I, which also benefits from Tom's rear calipers. The newer Gen II's have ABS which uses a different rear caliper, and this doesn't fit them (but they don't need it anyhow.)

Edit: here't the old thread: web page

 

[slaughterj]

I plan to do this once I scrape up the $$$$ - Tom, thanks for the pins!

 

[Tom F&L GoR]

I have an info/explanation/price sheet; PM or email me. I'm bringing more calipers to the machine shop tomorrow, so should have more 40mm sets ready to go in about 2 weeks - let me know if you're interested.

Thanks for the good reports, you guys.

 

[jcaspar1]

Tom,
Have you tried these with a Stoptech front setup. Would it shift the bias too much to the rears?

 

[EA6BPilot]

Tom,

Since I eventually want to go with this setup, what pads would you or anyone else recommend if my primary driving is done on the street? I use EBC Greens right now and they are ok (I have no other basis for comparison). For the track, I understand that Brakeman 3s are the way to go. Thanks.

Frank

 

[AG98RT10]

EA6, I went with Brakeman 3's and the Stoptech slotted rotors to help keep them from glazing in street cruising (which is 90 per cent of what I do). Aside from dust, which is a minor annoyance (keep an old Cal. duster handy), they have been superb. A little noisy, but good brakes squeak a little, they say. The Brakeman 3's stop, and now, unlike the greens.

 

[Chuck 98 RT/10]

I prefer PFC01 pads.

 

[PhoenixGTS]

Can you get a Porterfield R4S pad for the stock Viper calipers? I have had good experience with the R4S on previous cars (quiet and no dust).

 

[Achilles99]

Yes, you can buy those for the stock calipers.

Here's the best price I've found:
http://www.highperformancehouse.com/viper/

I believe if you call JonB, he directs you to the same company...

 

[Tom F&L GoR]

Jeff, I haven't tried this, but the math of piston sizes would say that a StopTech front caliper (with the smaller pistons) in combination with a 38mm rear caliper would be the same hydraulic clamping force balance front to rear as a stock front caliper and a 40mm rear. However, the smaller average piston size with the ST/38 combo means you'd have a 11% greater pedal effort for the same clamping force. Using a 40mm rear with StopTech fronts would give you a large rear brake bias and you would have to use an adjustable proportioning valve. A StopTech 4-wheel caliper system does this, too; their 4 piston rear calipers are "more" than you need and the car is dialed in with an adjustable valve.

Frank, I tried the EBC Greens and relative to OEM pads I felt I had to brake a little sooner and harder in my AX events. I do like the B#3 pads; they have good "bite" and don't have the "cold brakes" problems that harder pads sometimes do. My schedule is to put them on in the spring, they last for about the season, then back to OEM pads for the off season. How dusty either OEM or B#3 pads are doesn't bother me. AG98RT10 describes their performance well, and since he has 40mm rears, his experience relates to what you want to do. (Maybe since I AX or track more, I haven't had any glazing problems.)

Phoenix, I've had the R4S pads before and they are good for street and AX. However, they are not track pads (for Vipers, anyway.) I went through a new set (to the backing plates) in one 30 minute session. Ugly surprise.

 

[ViperRay]

Chuck,
Others have mentioned that pad also. How do they compare to BM3's? Are they sticky from the start or do they need to heat up a bit first. How's longevity compare? It's only for track use.

 

[PhoenixGTS]

Phoenix, I've had the R4S pads before and they are good for street and AX. However, they are not track pads (for Vipers, anyway.) I went through a new set (to the backing plates) in one 30 minute session. Ugly surprise.

Yep you definitely need the R4 without the "S" for the track. I just remember the R4S being VERY quiet and very clean on the street. I've had Hawk HP+ on other cars before and although they worked great even on the track, they were noisy and dirty. I have factory pads on the Viper right now and the sqeal under light loads and are pretty dirty.

 

[Chuck 98 RT/10]

PFC need to heat up. Once they do I have not found a better pad. I've used every EBC, BM3, Pagid R14 and some others I can't remember. Going to PFC01 easily outshined them all. For me anyway, some may like the modulation of other pads.

As always, check for yourself, but you should be able to get a complete weekend out of them.

 

[Tom F&L GoR]

I found the R4 (no S) and B#3 similar, but B#3 was less $$.

So if all pads wear down, where does the dust from the dust-less pads go?

 

[Nadine UK GTS]

After over 6 years of Viper ownership, this is the first year / summer that I have finally found the brake set up on my Viper for the track that I was desperately looking for (on a budget)! I do not care about dusty black wheels, they wash, and I would rather have that...than a Viper that doesn't look too pretty because it didn't stop too well!!

I have Tom's 40mm design mod OE rear calipers, OE front calipers with Roe titanium pistons, Stoptech front areorotors, OE rear rotors machine grooved (like fronts), OE prop valve intact / in place, PFC front pads, Brakeman3 rear pads, cool air duct kit (like Cones kit) and top of wheel-wells vented, Castrol SRF fluid changed yearly.

In the winter I switch to the EBC greens all round because I never get the brakes that hot or do high speed stops, they give a good feeling cold bite for on the road not pushing it on cold wet bumpy roads winter time!