Formula Vee Meeting during the Runoffs

[P-2 Mark]

Dietmar,

I've torn the entire car apart and it's now sitting up on two saw-horses waiting the removal of the
floor pan before I take the frame to the sandblaster, and paint shop etc...and then I'll turn my
attention to the body, and add paint to the current gel-coat.

Back to the manifolds....

I'm sure that Jim Schings or Bill Bonow can provide details regarding how they arrived at the size
of restrictor used on the FST's etc......It's seemed to work with close fields and alot of dicing on
the track. Good to hear from you!

Mark

[Speedsport]

Ugh. Here we go again. My view of the meeting was there was a general opinion in the room by the engine builders that were present that a spec manifold or restrictor plate would hurt costs in the long run. The engine builders commented that there was a possibility that new head design and carbs might have some benefit if a restrictor plate or spec manifold was used. From that the conclusion was made it would still be cheaper to buy a manifold then it would be to replace heads and carbs, and all the development that would go with it.

As Bill put it, yes the issue of what happened in NASCAR when they went to a restrictor plate came up, since it was relevant in expressing how expensive going to a restrictor plate could be.

OK- I had to go back and edit out a comment I made after I cooled off a bit. I don't want to start anything as I would like to stay out of the politics of this whole debate.

[Matt King]

I think there is a difference between a spec manifold and a restrictor plate in regards to cylinder head development. Most of the "NASCAR" talk was in regards to the restrictor plate specifically. If a spec manifold was created that flowed virtually the same as the current intake manifolds in use, but at a greatly reduced cost, there would be no more pressing demand to redesign heads than there is today.

[P-2 Mark]

Matt,

I'd be for the "spec Manifold" if it reduces the need for +$1500.00 manifolds! The $250.00 figure
proposed by someone(?) is very reasonable considering the other costs involved etc.......

Mark

[remmers]

I can tell you who wouldn't be interested in spec manifolds. everyone who went out and bought one of those $1500 manifolds, me inclusive actually. I'd be okay with a restrictor plate, but not a spec manifold. I'm sure everyone who bought those new manifolds to keep up with everyone else feels the same way regarding that proposition.

[cendiv37]

Actually, I don't feel quite the same. If I could spend $400 one more time and KNOW I was done chasing the pot of gold at the end of the rainbow, I would gladly turn my 2 year old, $1100 Kochanski manifold into a pretzel.

If you think this is over with the new proposed rules, I think you are deluding yourself.

Just my opinion, not the committee's. I have held my tongue too long...

[remmers]

True. Why not just write in the rules that you are not allowed to expand the manifold? We'd go back to where we were a few years ago, and I'm sure most people have at least one stock manifold lying around that they could use effectively. I know i only sent out my B-manifold to get blown out because I recognized this as Pandora's box.
The problem with a $400 spec manifold is then you have $1000 heads to match every year until the engine builders are finally happy with the power they get. At least the old formula the builders are well-versed in.

[cendiv37]

I also think the concern that a spec manifold will necessitate head or carb mods is overblown if not completely specious. We are not talking an increase in flow of 20%. We are talking a few percent at best, but getting to a consistent and stable max. flow over the long haul. If these kind of incremental increases were going to change head designs significantly, we would have seen this happening over the last few years. This is not the case.

I believe the arguments comparing FV restrictor plates or spec manifolds to restrictor plate costs in NASCAR are also specious. Those NASCAR engines are special designs with different cams, much higher compression ratios (than the "short track" engines) and a HUGE emphasis on fuel economy. I can't even remember if they are a different displacement too... Yes they spend huge amounts of money to win at Daytona and Talledaga, but they start from scratch with a whole new engine design and concept. In FV we would still still have to run the same cam, stay with the same compression ratio and we don't care much about fuel economy.

[SR Racing]

Bruce is correct. A restrictor plate or spec manifold with the current FV engine would not require any additional head development work. (Allthough, I can guarantee you that some builders will be advertising special "restrictor plate heads". I can also guarantee you that some people will buy them. ) It is possible that an additional slight cam retard would be advantagous, but that can be done at rebuild time at no additional cost. The NASA superspeedway motor and restrictor have NO comparison to a ACVW. (We have one here in the shop right now. Dodge 355ci / 750HP in a Mayfield Cup Car. )

We did a lot of testing with different restrictor plates on the 1600 and with the given cam, there was no real requirement for other changes. Even the a/f mixture stayed the same. (as long as all restriction is below the carb.)

[remmers]

In which case i suppose i have no issues with going to a spec manifold or restrictor plate. I know policing the restrictor plate would be simple, but how would you police a spec manifold? It would seem like it would be far more difficult than checking for a specially colored plate between the carb and manifold.

[FV80]

I think the real difference to consider between spec manifold and restrictor plate is HP. In order for a restrictor to be effective, it would need to reduce HP by a measureable amount - enough to negate possible benefits from manifolds. That would slow us down - which most people seem to oppose vehemently. OTOH, a 'spec' would provide (presumably) MORE HP than the best manifold that could possibly be built using a core (at least that would be the plan). Either method would allow continued use of all existing manifolds as the spec would be an ALTERNATIVE to using a core and doing anything you wanted to it.

The other consideration is LOSS of a manifold in an accident. Using a spec manifold @ ~$300 or possibly $400 would provide a MUCH cheaper alternative - we would no longer have to worry about trying to repair them, as it would likely be just as cheap to simply BUY a new one.

LOTS of things to ponder...
Steve

[remmers]

So the new spec manifold would be more horsepower than the current blown manifolds? How would this be cheaper unless we had SCCA Enterprises be the sole supplier? Or would the spec manifold be opened up to using different materials such as 3D printed plastic to get the price down?

[hardingfv32-1]

Would a restrictor plate at a 5-10% lower HP number be an equalizer? I can't help but think you are just adding another layer of restriction to the intake system. A superior head, carb, and maybe manifold will still make for a better engine even with the restrictor plate.

Is anyone evaluating the facts surrounding a spec manifold? Estimated current cost, how it would be fabricated and possible sources in the US? This can't be sold without some actual units that can be evaluated.

Brian

[brian]

With all due respect to everyone, there are smarter minds than ours struggling over the very issues being discussed here with the same results: no consensus. No one can say for certain what will happen in any senario until the testing is done and I believe it's naive to think that all the development on our motors is finished. I'd never go out to the shop again if I thought that!

[SR Racing]

I think the real difference to consider between spec manifold and restrictor plate is HP. In order for a restrictor to be effective, it would need to reduce HP by a measureable amount - enough to negate possible benefits from manifolds. ......ETC..

Stevan,

Spot on.. I am posting something that I put on the APEX sight for those that didn't see it :

A few points I want to make that have been distorted here and in other threads.

1. ANY increase in air flow through the carb results in additional HP. Someone who says a manifold that flows more air on the bench but doesn't make HP, is blowing smoke up your butt and/or didn't install the induction system correctly or tune it.

2. As Brian pointed out.. The vast majority of pumping losses in an FV in it's operating range are in the carb and manifold. (at this point in time). While head/valve flow is important, more people waste money there than in any other place. (BTW, "Pumping losses" are where the HP is lost. At some point the engine is working harder to get air into it than it can produce in HP. All engines are limited in HP by these pumping losses.)

3. Restrictor plates simply limit the air into the induction system. They have a tendency to equalize all other induction components, but only to a degree. For example (ignore the numbers here, I am only giving examples) assume a range of manifolds that flow 62 to 70 CFM. If I install a restrictor of some kind, that flow may now be 60 to 64.
Without restrictor I have a 8 CFM range from a good manifold to a top one. With the restrictor, the change is only 4 CFM. The smaller the restrictor the more the equalization, but it will NEVER make things equal.

The restrictor accomplished nothing other than to slow everyone down. All racers are still going to want the biggest manifold, restrictor or not.

4. In regards to the restrictor used in FST, while it does tend to equalize the carb flow (see above), it's primary intent was to keep top RPM and speeds down. (and save engines). The intake manifold on a FST can easilly support 100HP normally asperated, so trying to equalize manifolds is not really much of an issue. The pumping losses in a FST are all at the carb (and restrictor).

Net is, you slow everyone down and partially equalize the manifold situation, or you open them up with a spec one. Option one, no one will like. Option 2 comes with it's own bad... You move the pumping loss limitation up higher into the RPM band. Our shift points now become 6900 or 7000 instead of 6500-6600. We will be equalized, but blowing up more motors...

Jim

[FV80]

... Our shift points now become 6900 or 7000 instead of 6500-6600. We will be equalized, but blowing up more motors...

Jim

Why would I want to lower my shift point to 7000 ??? I shift at 7250 now ... (I WISH <VBG>).
Steve

[jpetillo]

I agree with Brian (BRM) that this issue can't be properly addressed without testing - spec manifold or restrictor plate. I have to admit, that I have no interest in our cars being slower than they are now (we run with other groups, and being yet slower may not help our image to potential new drivers), but I also don't want to see significant HP gains for reliability reasons. Also, a spec manifold does not necessarily mean that we will move our shift points up or HP peak up, but it can if we choose the wrong design. That's what the design and testing would be about.

Like Jim mentioned, a restrictor plate works best the more it limits (or reduces) the HP. If we don't limit the HP enough, then the manifold and head wars will continue as folks try to optimize other components to get the best combination. It will be effective to do development and so it will be done. I think that would be worse than where we are now.

About a spec manifold, the question is who would make it and what would their quality control be like. Also, that spec manifold might work great with my car and relegate another car to the slow lane. Since our cars can really wake up with small changes to the manifold shape, unit to unit manufacturing variations would be perhaps more important than it is when making a spec manifold for another application. A question is can someone make a spec manifold for FV with sufficient quality control and sell it for an acceptable price. I'm not sure SCCA is the place to go for a spec manifold. What ulterior motives might they have and might there be a conflict of interest? All these questions would need to be answered.

Neither solution would be as smooth going as it may seem, and it's not clear yet that either is a better solution than we have now. Each solution will spawn new development to work with these new components or to mitigate their limitations. Then those folks with the money will buy new collateral components. That's a given - that's racing. If we go with a spec manifold, would everyone have to buy one? If so, that would cost everyone in the community. However, not everyone is going to buy the ~$1200 manifold - they didn't before and they won't now. Which choice would cost the community more? We need to assess that as part of the equation.

I think the community can and will come up with many more questions that would need to be answered before we would consider making a choice to adopt one of them or stay the course with whatever new specs may be added to the current rules. And much testing and many arguments will have to be made. We, as a community on this forum and outside the forum, have invested a lot of time and effort into the manifold issue. Let's make sure we don't make a rash decision and have those efforts go to waste.

John

[smsazzy]

Per Jim's point, I think that is why you make the control manifold bigger and limit that with a restrictor plate. If you combine the two, you get the best of both worlds. a cheap manifold, with a restrictor plate to stop people trying to acid etch and go crazy with the control manifold.

[jpetillo]

That's a good point. Jim's post was good, but I didn't get that point from it even after reading it a second time.

[cendiv37]

Per Jim's point, I think that is why you make the control manifold bigger and limit that with a restrictor plate. If you combine the two, you get the best of both worlds. a cheap manifold, with a restrictor plate to stop people trying to acid etch and go crazy with the control manifold.

Exactly!

[SR Racing]

I have to admit, I didn't even consider that. (spec manifold and restrictor). Not unlike what some other venues do.

And, due to the SCCA method of operation, you are 3 years away from making it happen. BTW, SCCA Enterprises markup on the SCCA car is ~300%. So, I doubt the above combo will be much under everyone buying a MonsterManni <g>

And THEN the engine builders will be proclaiming their new "Restrictor Plate" heads.. Someone will buy a set and win a race and the whole world will need them.. This will go on for years and years.

The only guys that make out are the vintage guys as all these old parts go to them at 50% mark down..

[cendiv37]

And the guys who sell Monster Mannies and their ilk.

[brian]

I think the key to any proposal is cost. The less the better. The idea of new manifols and restrictor plates won't be the least cost option. Tighten up the rules on the manifolds as proposed in the meeting and lets see what happens. Why wait for SCCA, gentlemen's agreement would suffice until the rule process catches up.

[hardingfv32-1]

This is not meant to be arrogant or vindictive, but Bruce is right that there is only one way to control manifolds, a spec manifold. I have been throwing darts at the wall when it comes to manifold development under the present rules. More rules will just force me to focus my development into a narrower range. I have made friends with most my customers and now feel a need to make the best manifolds available for them even if that means replacing everything. I do not mind spending the time to keep these friends happy. I doubt the other manifold makes have the time or mindset to match this level of customer service.

I'm going to get a year off to refresh while the rules settle out, so I should be ready to go in 2011.

Brian - Monster Manies

[hardingfv32-1]

So Bruce, you will round up a spec manifold for Jim to test? Just shoot for something that is slightly better performing as discussed earlier. I think it is assumed that all old manifolds will remain legal.

I could fab something but I'm not sure about tubing size. I would assume something about 1.120" OD @ .060" wall. This should be available, although DOM (smoother) would be more problematic. I also need to find a mandrel bender with internal dies. I see a big fab issue at the junction of the downtube. How is this done?

I cannot make these in mass, just something to eval.

Brian