REV LIMITS on V8s- This season....

[Mike Bell]

Mentioned on the Martini thread, now there's more.....

From Masters Historic Racing and "aimed at slowing the pace of development and controlling the costs of historic motor racing".

"This year we are going to implement a year’s trial on the restriction of engine revs, starting with V8-engined cars competing in the Gentlemen Drivers and Pre-66 Touring Car championships. All V8-engined cars competing in these two Masters’ championships will be restricted to 7,000 rpm for 2015. From the lessons we learn during this coming season and, assuming that the results are successful, we plan to implement rev limits across all the series’ for all the various engine types competing from 2016.
We believe that this new regulation is fair and reasonable and will require only modest cost and effort for our drivers to implement. However, if you believe this not to be the case and that making the required modifications to your car would be unacceptably onerous, please contact the Masters team to discuss your situation.
Technical Specification
MSD 6AL ignition control (part number MSD 6425 only)
Note that no other device will be allowed.

Fitting and Set-up Instructions
· Any control of the advance curve must be RPM related only, and be executed by the sole means of the distributor.
· No external control of advance system is permitted, and MSD ignition boxes that control advance, or allow advance mapping, are not permitted.
· The MSD box must be mounted out of reach of the driver.
· This system will be easily monitored by our scrutineers by an MSD controller which will allow the RPM limits set to be checked.

[Moosehead]

I guess there's two ways of looking at that.

1. Yes the rev limit will stop the increased power at higher revs - which would mean engines *may* last longer between rebuilds so increasing the viability to those on lesser budgets.

2. Those with larger budgets will just get their engines guys to do more development work to increase the power/torque across the rev range up to the new limit.

Result: Those with more money will still have better engines.

[Mike Bell]

Originally Posted by Moosehead

I guess there's two ways of looking at that.

1. Yes the rev limit will stop the increased power at higher revs - which would mean engines *may* last longer between rebuilds so increasing the viability to those on lesser budgets.

2. Those with larger budgets will just get their engines guys to do more development work to increase the power/torque across the rev range up to the new limit.

Result: Those with more money will still have better engines.

Re your last comment- I don't think anything will change that!

The DFV engined F1s are already limited and I am told this does reduce rebuilds, which I think are £25k a pop. And yes, engines are optimised to give best torque and power in the Rev range restricted to!

I don't know much about the "Rev limiter" required but it looks expensive. Not sure if it is best choice or someone did a good selling job......

[Cliff Ryan]

I already use an MSD with a 7200 rpm chip in it as I have a self imposed 7000rpm limit.

So looks like I'm ahead of the curve for once

[Mike Bell]

Originally Posted by Cliff Ryan

I already use an MSD with a 7200 rpm chip in it as I have a self imposed 7000rpm limit.

So looks like I'm ahead of the curve for once

You're always ahead......

The unit you describe is the one some thought would be specced, but the choice (AL6 6425) has rotary adjusters to set the limit.....

[PeterMorley]

Originally Posted by Mike Bell

Re your last comment- I don't think anything will change that!

The DFV engined F1s are already limited and I am told this does reduce rebuilds, which I think are £25k a pop. And yes, engines are optimised to give best torque and power in the Rev range restricted to!

I don't know much about the "Rev limiter" required but it looks expensive. Not sure if it is best choice or someone did a good selling job......

But when they introduced the DFV rev-limit someone reconfigured the engines to produce more power...
DFVs have come with various bore/stroke and valve size configurations over the years and someone came up with a new configuration that worked better at the new rev-limit, hence remaining "competitive" required a rather expensive "rebuild".
A normal DFV rebuild should be much less than 25 grand (7½ if you're lucky), 25 sounds more like the cost of modifying to the new spec.
But the rev-limit does increase the mileage between rebuilds and is closer to what would have been used in period.

[delta]

One of our E Type drivers "not Colin " rang in a panick yesterday.

[Duddha]

My very own personal view on the subject of performance here.

At least, the field won't be able to argue like "His engine is reving like f***!" and I think it's more of a performance cap like fine, live it to that point, driver will be the difference. Of course, some will rework it and find a little advantage with an engine suited to that limit but then it will be about drivers and we'll see if some argue like "Ok, he's talented"

[Colin McKay]

Interesting that this initiative comes from the more expensive end of the club spectrum.

[GORDON STREETER]

Reading the article as regards the AC cobra raced (in period and now) at Goodwood comparing lap times I don't think the chicane was used then was it ?
Just had a quick Google and it appears it was !

[Tim Falce]

Why limit just V8s and not everything else that have rev bands that have increased significantly over the years?

[Al Weyman]

I don't think it will have that much effect on V8s, it would on a 4 pot though.! My engines will rev to 7800 but I generally shift at about 6200 to 6700 as not much to be gained going higher.

[one-two]

Does anyone have the mailing from CER referred to on the other thread and/or the Masters mailing please? These are very interesting initiatives but, as is often the case, it's hard to find relevant info on the relevant websites! Many thanks, Robert

[Moosehead]

I already run the MSD unit with rotary adjusters (though its fitted in a position that makes changes difficult) and like Cliff mine is set at 7k.

I've seen them fitted on trans tunnels and other reachable places in the car though I'm sure theres a rule in the blue book stating that ignition components must not.

[Heightswitch]

Power is a factor of Fuel flow and rev limit. A sensible rev limit will always level the playing field. The development of cam profiles to maximise power and torque is generally more achievable for most…its expensive components and billet items which become a requirement for high revving engines that costs the money.

I think my 6AL has little plug in limiters and mine is 6k revs from memory…

Limiting power on a V8 is simple..

1. rev limit
2. 4 barrel carb only
3. Limit the size of the brakes in terms of overall rotor diameter and original callipers. Not strictly engine but still the most effective way to control lap times!

N.

Thankfully I am still at the learning to drive faster with what little power I have stage

[Mike Bell]

Originally Posted by one-two

Does anyone have the mailing from CER referred to on the other thread and/or the Masters mailing please? These are very interesting initiatives but, as is often the case, it's hard to find relevant info on the relevant websites! Many thanks, Robert

Robert, the text quoted is more or less the mailing in both cases.

Moose, Masters state that the MSD unit must be mounted out of the driver's reach. Nothing about it being out of the mechanics reach though!

[Duddha]

Originally Posted by one-two

Does anyone have the mailing from CER referred to on the other thread and/or the Masters mailing please? These are very interesting initiatives but, as is often the case, it's hard to find relevant info on the relevant websites! Many thanks, Robert

Contact me Robert if you have any question regarding CER, I'm part of the competitor's office but there is nothing else appart from what Mike did copy and paste on the other thread.

[Lancsbreaker]

Originally Posted by Al Weyman

I don't think it will have that much effect on V8s, it would on a 4 pot though.! My engines will rev to 7800 but I generally shift at about 6200 to 6700 as not much to be gained going higher.

Wonder what rev limit they will set when they get round to the Imps? 9500 ?

[delta]

Have to applaud masters . I bet this latest rule is the most talked about topic in historic racing at moment

[Al Weyman]

Originally Posted by Heightswitch

Power is a factor of Fuel flow and rev limit. A sensible rev limit will always level the playing field. The development of cam profiles to maximise power and torque is generally more achievable for most…its expensive components and billet items which become a requirement for high revving engines that costs the money.

I think my 6AL has little plug in limiters and mine is 6k revs from memory…

Limiting power on a V8 is simple..

1. rev limit
2. 4 barrel carb only
3. Limit the size of the brakes in terms of overall rotor diameter and original callipers. Not strictly engine but still the most effective way to control lap times!

N.

Thankfully I am still at the learning to drive faster with what little power I have stage

4 Barrel carb wont slow them down much, its all they had in NASCAR for years, and the imposition of standard brakes isnt a good plan IMHO as all it does is play into the hands of a particular model thats blessed with superior 4 pot calipers and maybe rear discs. I would never run the original brakes on my old car again even to get into Goodwood Group 1 as its simply dangerous to allow cars to have 500bhp engines then restrict them to sliding single pot calipers and drum brakes, makes no sense to me.

[Bruce Chambers]

Originally Posted by Cliff Ryan

I already use an MSD with a 7200 rpm chip in it as I have a self imposed 7000rpm limit.

So looks like I'm ahead of the curve for once

The original 6AL had the plug in chip rev limiters, this was replaced with the rotary dial version the "Digital 6AL" by MSD a number of years ago now, so the 6425 is the currently available version. Interestingly the rev limit element of this ignition is a side benefit, the primary purpose of this ignition is to increase ignition energy and power. It is a multiple spark, capacitive discharge unit, giving massively increased ignition energy compared with conventional points and coil set up, allowing an increased plug gap to be run and is particularly beneficial to carburettored race engines which tend to run fairly rich in the mid-range and the spark energy of the 6AL is able to fully ignite this less than optimum mixture and improve mid-range power significantly, whilst still supplying a meaty single spark at higher engine revs. Most series would not allow this mod fro pre 1970's cars, being not available in period.....

[Al Weyman]

GM HEI ignition system is all I have and gives good service with slight modification. I think too much is made of MSD, as a certain well known Dutchman said to me at Brands all you need is the HEI a good spark and fuel and the jobs a goodun. Ive used MSD Modules and have one in my later car and have had trouble with them and even when working OK dont see any difference. Its when I was having trouble the Dutchman told me the first thing they do when they get a car in is rip the MSD out and advised me to do the same!

[Cliff Ryan]

Originally Posted by Bruce Chambers

The original 6AL had the plug in chip rev limiters, this was replaced with the rotary dial version the "Digital 6AL" by MSD a number of years ago now, so the 6425 is the currently available version. Interestingly the rev limit element of this ignition is a side benefit, the primary purpose of this ignition is to increase ignition energy and power. It is a multiple spark, capacitive discharge unit, giving massively increased ignition energy compared with conventional points and coil set up, allowing an increased plug gap to be run and is particularly beneficial to carburettored race engines which tend to run fairly rich in the mid-range and the spark energy of the 6AL is able to fully ignite this less than optimum mixture and improve mid-range power significantly, whilst still supplying a meaty single spark at higher engine revs. Most series would not allow this mod fro pre 1970's cars, being not available in period.....

It's allowed in the series I run in

[Mike Bell]

The two Pre-66 series Masters are requiring V8s to run the MSD unit in already allow electronic ignition, so don't believe any advantage to be gained. However, I can't confirm that as there are no series regs on Masters website at moment....

[Mike Bell]

Just to clarify, MSD do still market a 'module' rev limiter with plug in 'chips', but as an add on to one of their ignition amplifiers. A lot more £££ than the 6425! Guess this was chosen as still just about affordable......