On average how much will your lap times drop going from street tires to R comps?

[Serious]

just curious how much lap times will improve with the switch from street tires to R comps?

obviously i know its going to vary between tracks/conditions... just looking for a guesstimate average.

[jacy]

if I knew what I was doing, probably 10 seconds. 5 seconds is about what I see at TWS.

[=BA=]

That's what I'd say, about 5 sec on the local 4,3 km track here.

M3 321 HP on streettires runs about 2:15 and on Yoko A32R H's + Intrax coilovers 150 KG weight reduction about 2:05, so a better tire would even make it a few sec faster. A few sec is in the coilover + weight reduction as well offcourse.

[CABimmer]

Never bother to time myself. I am only in DEs and dont drive 10/10ths. Stop watches cause wrecks at DEs

[jacy]

Never bother to time myself. I am only in DEs and dont drive 10/10ths. Stop watches cause wrecks at DEs

How do you know if you are growing your driving skills? I personally find lap timing (not a stopwatch), data aq. and now video to be very useful tools for learning. I recommend them highly to anyone who is serious about improving their driving technique and their ability to teach others.

[CABimmer]

Any decent driver can tell when they are hitting apexes correctly and driving smooth, this is what I look for. If you really want to look at numbers you can look at your exit speed. Most events here do not permit timing devices, And again as I stated DEs are 8/10ths not 10/10ths. Most people around you are not at a level where you can drive at that level and not cause an incident. You will almost never get a traffic free lap and a clean lap time.

[91M5]

Any decent driver can tell when they are hitting apexes correctly and driving smooth, this is what I look for. If you really want to look at numbers you can look at your exit speed. Most events here do not permit timing devices, And again as I stated DEs are 8/10ths not 10/10ths. Most people around you are not at a level where you can drive at that level and not cause an incident. You will almost never get a traffic free lap and a clean lap time.

I have to disagree. I have been timing for years where allowed and it does give you lots of feedback, the most important of which is consistency. Sure you may hit traffic but that is not every lap. I don't look at the times until after the session. While I might be able to discern I just drove a quick lap I can't always tell I was .8 seconds faster on average than my last session or last time at the track. While I don't drive 10/10ths and try to stick to the 8-9/10ths rule there are certain corners where you can push a bit harder due to runoff.

[CABimmer]

Just a different philosophy, I don’t think a DE is the place to be pushing for better times. That’s all.

I’m not saying there is no benefit to data acquisition or lap timers. If you are driving a perfect line and looking to shave off a few tenths you need to be doing open lapping not DEs.

Back on Topic you will be faster.

[phredden]

Nice banter, lads, but bBack to the topic at hand.....

There are 'street tires' and there are 'street tires'. Assuming you mean garden variety, OEM stuff, we've found about 3-4 seconds per minute elapsed, with a big delta on circuits depending upon how twisty it is, etc.

Vs. a really good set of Kuhmo MXs, or Azenia, etc., about half that as a WAG.

Having said all that, there's also a big delta between 'r' compounds, a Yoko A048 vs. a Kuhmo 710/Hoosier, like night and day, a fresh set of the later being over a second per minute quicker.

As hundreds of folks on this forum have proclaimed, the biggest bang for the buck for a DE r compound is the Toyo RA1, hands down...relatively cheap, pretty darn sticky, and lasts a LOT longer than anything else out there.

[onrailsm3]

I'll stick my nose in on this one.

CABimmer is right, at DEs it's not about lap time. Most DEs prohibit timing of any type cause it changes the insurance liability.

The way I judge is if I gain or lose ground on a car I know is petty even to mine in performance. I usually settle in behind someone I can't pass outright and start to play with them and see if I can match their pace. After the session I usually shake hands with the guy and we grid up together the next go-round so we can gauge eachother's line, performance etc.


Granted, I am running solo 95% of the time so it's more of a lapping session.

Second fact, exit speeds are everything at DEs. It's a way to gauge your performance turn by turn. It's the easiest way to judge consistancy and see tangable evidence that you are getting smoother.

Back on topic, R-comps are faster but more dangerous. On most R-comps there is very little feedback with squeeling and when they do let go there is alot less transition from grip to slip.

On the other hand, you'll never want to go back to street tires on the track once you've had R-comps on your car. See sig, you can't do that on street tires.

RA-1s, like phreddeb recommended.

[91M5]

If you are driving a perfect line

What's that? :-)

[AndrewBall]

2 seconds maybe.

[GroovinPickle]

A rule of thumb used by autocrossers is that for a driver on street tires, multiply the time by 0.96 as a handicap relative to R comps. Some folks think 0.97 is more accurate, but there are many variables and it's just a guess anyway.

That's not directly relevant to the question as it pertains to a road course, but at least it gives some perspective.

[M Dizzle]

1 minute.

[SlammedE30]

2 seconds maybe.

I think it is vehicle dependent, but I can guarantee if I put street tires on my race car, my lap times would be far slower then two seconds off my best.

[JClark]

I time myself regularly at DEs, open track days, and time trials. Kuhmo MXs to RA1s cut between 4-4.5 seconds off my times at Watkins Glen (3.5 miles, long straights), 2-2.5 seconds at LRP (stupid short bumpy curvy course), and 3 seconds at Mont Tremblant (2.5 miles). Dont have any street tire data for other tracks.

Re: timing at instructional DEs or other: I just started using data acq. and its an unreal learning tool. You'll find time you never knew you were losing and the next time you go back out you'll wonder why you ever made that mistake.

[1996 328ti]

A lot depends on your comfort level too. Maybe it is just me.
For 2 years I was not 1 second faster with RA1s over my T1S.
After an instructor got me off my plateau, my times improved slightly on RA1s.

[AndrewBall]

I think it is vehicle dependent, but I can guarantee if I put street tires on my race car, my lap times would be far slower then two seconds off my best.

thats about all i found in my street car from Potenze Re750's to RA1s RA1 isnt really a race tire but not far from a hooiser

[mmark.]

If you don't have a decent set up, ie just slap the soft Rcomps on a stock suspended macstrut car, you'll be disappointed.
Without adressing the loss of negative camber under conditions of dynamic roll, you won't realise much advantage from your stickies.
The Rcomps will exacerbate the body roll until they overheat.

m

[Serious]

If you don't have a decent set up, ie just slap the soft Rcomps on a stock suspended macstrut car, you'll be disappointed.
Without adressing the loss of negative camber under conditions of dynamic roll, you won't realise much advantage from your stickies.
The Rcomps will exacerbate the body roll until they overheat.

m

how come this isnt the case with the m3 csl?

[=BA=]

Don't fully agree that it doesn't work either, a old E30 325i with cheap shocks, 20$ loweringsprings on slicks or R888's corners faster than a E36 M3 on streettires, big ass coilover setup with camberplates.

[mmark.]

how come this isnt the case with the m3 csl?

You may want to re read my entry, and the spec sheet of the CSL.

m

[mmark.]

Don't fully agree that it doesn't work either, a old E30 325i with cheap shocks, 20$ loweringsprings on slicks or R888's corners faster than a E36 M3 on streettires, big ass coilover setup with camberplates.

You're not really comparing the same bone stock chassis on Rcomps.

In my opinion,my response to your observation..forgive me, is more weight and more straightline speed in your E36.
Compare either of your cars with a bone stock chassis and rcomps, to your prepped chassis on rcomps.

In my experience, I used a bone stock E30 m3 with street tyres, and then Rcomps, and the improvement was slight...the car was good either way....relatively light.
The Improvement of a different E30M3 was large, with coilover suspension, higher spring rates, camber compensation , and rcomps.

I tried my bone stock E36M3 with Rcomps and the car was terrible after two laps. the weight and body roll were destroying the outside pair of tyres.
It took Lowering, higher spring rates, and most importantly camber compensation, for the car to get any benefit from the Rcomps.

The venue was a 2 mile road course.

The E30 M3 was set up better from the factory and has a shorter wheelbase and less weight (2800 plus driver) than a stock late E36 M3(3400+ plus driver), so the Rcomps had a better platform to work with.

Everything works as a package. There is a reason why money is spent on chassis work (springs, bars, camber plates, damper tuning), if and when the rules permit it. Even the SCCA stock class allows some work on the platform .

You may notice a benefit with Rcomps on a stock car in a low speed autox situation where the run is over before the tyre gets to the upper end of its operating temp range, but the road course environment is a bit different.

My point is that you fail to get the most out of your R comps if you don't have a decent platform to begin with.

m

[joenationwide]

On the other hand, you'll never want to go back to street tires on the track once you've had R-comps on your car. See sig, you can't do that on street tires.
.

I must challenge that statement, sir!



This is on Yoko Advan Neova ADO7s street tires.



I've heard that in autox, R-comps are worth about 2 sec. on a 60 sec. course (over street tires). Of course there are lots of variables, and lots of pseudo R-comp/street tires now (Neova AD07s, Stones RE01Rs)...

[trumperZ06]

Good rule of thumb is ~ 5% faster on " R " compounds...

workks out to ~ 3 seconds/minute/which is a bunch !!!