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Behind the 'pop-off' row

As we reported on Autosport.com over the past couple of days, CART has adopted a new turbo boost limiting 'pop-off' valve for the rest of the season, starting in Detroit this weekend. The new pressure relief valve is three-quarters of an inch taller than the previous valve, with an extended base or skirt. The extension is designed to minimise the possibility of 'out-witting' the valve as CART believes two of its engine manufacturers have been doing

On Friday evening Honda protested CART's decision to mandate the use of the new 'pop-off' valve, but the protest was denied. Honda has three days to file an appeal and Tom Elliott, president of Honda Performance Development, said that will definitely happen. Elliott added that Honda is also considering suing CART.

"We will appeal and we are considering further action," Elliott said. "Our biggest concern is CART's total disregard for how this thing was handled. It says a lot about do we want to be involved in the future with CART. It shows either a complete lack of knowledge of engineering or understanding of physics. For them to say this has no impact with a spacer of this type is ridiculous."

CART was informed by Toyota a few weeks ago that Toyota believed Honda and Ford/Cosworth had discovered a way of obtaining three more inches of boost pressure by accelerating the flow of air across the pressure sensor inside the plenum chamber. A change of air pressure takes place like it does with a carburettor venturi as the air/fuel mixture is compressed and accelerated.

"There's a Bernoulli effect you can achieve by very carefully crafting your plenum design," said Lee White, manager of Toyota Racing Development. "It's within the rules, but since Motegi a year ago a huge engineering and corporate effort has gone into this. It's been refined to a high level."

White says Honda and Ford/Cosworth have enjoyed much more horsepower than Toyota this year. "When we finished last year at forty inches we had over 900 horsepower," White said. "So you're talking seventy-five horsepower.

One of Toyota's leading team owners, who refused to be identified, said Toyota had been told of the power-boosting trick by a former Honda engineer who joined Toyota last winter.

"I can't prove that anyone cheats," said Toyota's White. "I don't know that anyone cheats. We proved in theory that it could be done. We showed our data to (CART's technical bosses) Kirk Russell and Jeff Horton and suggested some things so that everybody was playing on the same field, not at opposite ends of the continent."

Honda and Ford people say they knew nothing about the new 'pop-off' valve until a test last Tuesday at Michigan Speedway.

"We first became aware of it at the Michigan test," said Robert Clarke, general manager of Honda Performance Development. "CART didn't bring it to our attention. One of our teams notified us."

Clarke said Honda was unhappy that an additional variable was introduced into the test of reduced power and added drag for next month's Michigan 500.

"We agreed on the spec and went to the test to evaluate this combination, then they threw this at us," Clarke commented. "We said it would have a major effect on the engine. How would it effect performance, response and reliability? Each team did one outing at Michigan and then took the spacer off."

Clarke said CART did not confirm that the new valve would be used in Detroit this weekend until it issued a formal bulletin to the teams on Friday morning. He said Penske team manager Tim Cindric remained in close contact with CART during this time. Clarke added that CART's vice-president for competition Kirk Russell was given the go-ahead on Thursday by CART's board of directors to require the use of the new 'pop-off' valve.

"We continued our discussion with CART," Clarke said. "Tim (Cindric) met with them on Wednesday and Thursday and continued to argue our position. Through those meetings there was no clear mandate that we would have to run that valve this weekend. It wasn't mandated until the bulletin issued on Friday morning. It was discussed in the franchise board meeting on Thursday and they gave Kirk the authority to make the call."

Meanwhile Toyota drivers Bruno Junqueira, Nicolas Minassian and Scott Dixon took part in a rookie test at Mid-Ohio on Wednesday and were able to test the new 'pop-off' valve. Toyota also ran some dynomometer tests with the new valve a few weeks earlier. "We're very disturbed about this," Clarke said. "Kirk basically admitted Toyota had prior knowledge and did some dyno tests around Milwaukee time."

Ian Bisco, vice-president of Cosworth USA, corroborated Clarke's view. "Our guys showed up at the Michigan test and were thrust a valve that was different than anything we'd seen," Bisco said. "We agreed to run it and proceed with caution. Since then there were hints from CART about running it in the future. There was no talk of it being mandated for Detroit three days away.

"Is it hurting our performance?" Bisco added. "We don't know that for sure because we need to have the same aero and wing package to evaluate our performance. I think the point is every engine is different. It has different breathing. Some it might effect, some it may not."

Toyota's White disputed the arguments of Clarke and Bisco. "HPD (Honda Performance Development) called us on Wednesday and asked if we could supply them with a new valve," White said. "We told them to contact the vendor Metalore, and they had some on the shelf. Our understanding is they ran it on the dyno that day. All this talk about no time for testing is ridiculous."

Most of the Honda drivers complained on Friday and Saturday that their engines were down on boost by three inches and that it was very difficult to control the amount of boost delivered with the new 'pop-off' valve. Toyota's White said this was further proof that Honda at least had been cheating the previous valve.

"If you're having problems with your mapping it's because you don't have a 37 inch map, you've got a 40 inch map," White maintained. "If they're at 34 inches, that's because they've been three inches over. It's blatant lying. There's no way to sugar coat it."

White admitted that CART doesn't have the personnel or technical capability to contend with this kind of technical challenge. "It's a lack of resources and personnel. They have very limited resources and are trying to cope with giant corporations prepared to spend millions. They just can't match the resources and people that we have."

White said Toyota is also convinced that traction control has been in used in CART for some time. "There's no question that traction control is being used, but CART is not capable of regulating it," White added.

Honda's Clarke said the turbocharger plenum chamber is one component that has been strictly regulated by CART. "The fact is the plenum is probably one of the most closely defined parts of the engine," Clarke said. "The rules say you must submit the plenum and attachments for approval and all our plenum designs have been inspected, reviewed and approved by CART. They are the same spec here as they were at Motegi and Milwaukee.

"This is extremely frustrating for Honda," Clarke added. "The relationship between CART and the manufacturers is based on trust and I feel CART has totally violated that relationship. This was totally in the wrong direction as far as building relationships and trust that can lure manufacturers to the series and keep them in the series. It's almost become the rule de jour. Probably the biggest issue is that one manufacturer had prior knowledge of this and was given an opportunity to test and evalute the new valve."

American Honda boss Elliott reiterated Clarke's statements. "CART approved our plenum chamber," Elliott said. "They approved every aspect of the engine."

Elliott said Honda is seriously reviewing its continued involvement in CART. "I'm very unhappy," Elliott stressed. "In the eight years we've been in CART I've never seen anything handled as poorly, and to do it in collusion with one of the engine suppliers causes us great concern. It really does question why we're here. I seriously question the value of our long-term interest in CART."

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