roush cars in stock and super stock

[Tim Kish]

Originally Posted by stockracer

Mr. Kish you will probably be most knowlegeable on this topic. With an intercooled car isnt it true that the car is less affected by the weather changes because the intake air can be made the same every run? Im only asking because I dont know. And in the blueprint specs it says Throttle Bore 2@62 mm, does that mean a total of 124 mm or a twin bore total of 62mm? And how will this compare to the SS/DX car that went 7.99 a few years back? Or is it any comparison? Once again I dont know. But one thing that did stand out was the 510 hp combo is 500hp in gt, thought that was kinda odd.

An intercooler will not alone reduce sensitivity to weather changes, without changing the intercooler setup the delta Temperature will remain consistent so if ambient increases 10deg, so will charge temp. Now much like icing an NA intake, you can run ice water through the intercooler (water to air style) - again that is not a means of reducing sensitivity to weather changes from perspective of improved consistency.

[SSDiv6]

Originally Posted by Alan Roehrich

Evan, I agree, except on two points.

The ZR-1 Corvette, unless something else has changed, is a pure Chevrolet vehicle, manufactured as sold at GM, and not farmed out to another company to modify it, so the Roush cars are not exactly the same as the ZR-1 Corvette. That does not really matter.

On the supercharger, if you'll read or re-read my earlier post, note where I wrote that Roush is using the largest version of the Eaton supercharger on a 4.6L V8, and Eaton says the largest version is big enough to feed large displacement V engines. I can't tell about Eaton for sure, but a 4.6L V8 is not what I call a large displacement V engine. What that means, given that Eaton says it has better than 76% thermal efficiency, is that it probably will perform a lot different and a lot better than the blowers we're used to seeing, if Eaton is telling the truth. That DOES matter.

Again, I'm am NOT opposed to letting them race. But NHRA needs to do a LOT better job factoring them than they have done factoring a lot of cars, historically. And if they miss, they don't need to drag their *** about fixing it. We've got enough severely underfactored cars in the class now.

Alan, Chevrolet may assemble the car, however, the R&D for the engine and drivetrain, is outsourced to different companies including Roush, Katech and a few others. Also, this is not the first time a car company has a car built outside the assembly line. Let's not forget the Dart/Hemi 'Cudas, 1968 & 1969 Dart/Cuda 440-4, and other cars such as the Yenko and Hurst cars.

Although they may be using a high efficiency S/C, like Evan said, the heat build up is always the limiting factor. I had my learning curve with the Buick Series I and Series II S/C engines and believe me, whenever you increase the boost, a lot of other issues arise.

[Alan Roehrich]

Originally Posted by SSDiv6

Alan, Chevrolet may assemble the car, however, the R&D for the engine and drivetrain, is outsourced to different companies including Roush, Katech and a few others. Also, this is not the first time a car company has a car built outside the assembly line. Let's not forget the Dart/Hemi 'Cudas, 1968 & 1969 Dart/Cuda 440-4, and other cars such as the Yenko and Hurst cars.

Although they may be using a high efficiency S/C, like Evan said, the heat build up is always the limiting factor. I had my learning curve with the Buick Series I and Series II S/C engines and believe me, whenever you increase the boost, a lot of other issues arise.

I know one of the engineers in the Corvette program, there's a lot more done in house than you might think.

The Roush cars are also intercooled. That will also help a little on the heat build up.

[Fred Popov]

I look forward to seeing these new Mustangs racing. I’m glad that Detroit has recognized NHRA stock racing and has made an attempt to market models that are purpose build. It has been done back in the 60’s so why not now. So what that they are Roush and not built by Ford. With higher fuel economy (CAFÉ) requirements, it’s a way for Ford to not get bothered by the EPA ratings. Ford built the supercharged Cobra in 2003 and 2004 and it is rated at 390 hp. I don’t read any complaints about that car. In fact that car has more potential than the ROUSH since it a 4 valve head. The Roush is a 3 valve head on the same 281 ci block. Last year a lot of people complained that the FI cars were being combined with the carb cars. It seems that everything has worked out fine and the FI cars are not completely dominating all the classes. I don’t think that the Roush will cause too much trouble for the high compression big blocks from the 60’s, especially for a small 281 ci being rated at 435 hp from the start.

Fred,

[Colin Wigle]

Tony

The car has been in the guide for a couple of weeks the weights, HP engine specs all there, take a look before you jump the gun. Trust me I love sixtys muscle cars for that matter all muscle cars and race cars alike. You are just missing the point the OEM,s would like to run current cars and curent power it only make sence. I am aproached at the races all of the time, " is that a 3 valve or a 4 valve a 4.6 or 5.4 and so on" when I explane that is has a 1971 power plant. it sparks confusion for the most part. That was my choice from the begining and have invested quite a bit. so that is how it will stay for now. however I believe that the cars that run stock and super stock not GT with current cars and power will get the attention. and that attention is what the OEM's need.

Colin

[Tim Kish]

To implement boost control as a tech control is actually an unfair regulation on a forced induction engine. As boost is a measure of manifold back pressure you can increase the boost level in the manifold by changing the cam profile - LESS Lift or duration. You have made no changes to the blower/turbo at this point but the boost gauge reading has changed. Relative to performance this may/may not help, higher manifold pressure yields higher airflow velocity but also labors the charger more which creates added heat - its a function of the engine combination. My point is it is not directly indicative of power output. I am working on an application now that runs 8psi boost on the low power variant and 5 psi boost on the high power variant. Exact same supercharger system, drive ratio, etc - the only hardware difference is the cam profile. The low boost version makes 50Hp more.

A regulation on boost level would be no different then to limiting all NA applications to the factory rev limit (Nobody runs higher RPM than the OEM do they?)

[Jeff Lee]

Yes Tim, good points..So if a supercharger or turbo racer wants to run S/SS & the cam, exhaust or other modifications to factory alter boost then the racer will have to deal with it. The racer should still have to run OEM specified boost, not an NHRA arbitrary boost figure, but OEM spec, possibly a +/- boost number. The factory limits boost and the racer should follow those guidelines. If it takes
5K RPM or 8K RPM to see maximum boost so be it.
After all, the factory provides all the other numbers we need, right?

[SSDiv6]

Originally Posted by Tim Kish

A regulation on boost level would be no different then to limiting all NA applications to the factory rev limit (Nobody runs higher RPM than the OEM do they?)

You are too funny!!!

[Mark Yacavone]

You reckon NHRA's gonna buy a bunch of telltale boost gauges and then loan them out for free?

[Sean Kennedy]

Originally Posted by Tim Kish

To implement boost control as a tech control is actually an unfair regulation on a forced induction engine. As boost is a measure of manifold back pressure you can increase the boost level in the manifold by changing the cam profile - LESS Lift or duration. You have made no changes to the blower/turbo at this point but the boost gauge reading has changed. Relative to performance this may/may not help, higher manifold pressure yields higher airflow velocity but also labors the charger more which creates added heat - its a function of the engine combination. My point is it is not directly indicative of power output. I am working on an application now that runs 8psi boost on the low power variant and 5 psi boost on the high power variant. Exact same supercharger system, drive ratio, etc - the only hardware difference is the cam profile. The low boost version makes 50Hp more.

A regulation on boost level would be no different then to limiting all NA applications to the factory rev limit (Nobody runs higher RPM than the OEM do they?)

If they did limit boost than it sounds like your goal would be to find the best cam and boost combo to make the car run fast with the limitations set. Why would this not be a great way of limiting these cars adn still being a competitive combo in the class? Boost does not necesarily have to be limited to factory, so there could still be room for performance gains.

SSDiv6,

Is there a thread on classracer that you don't pop into and know EVERYTHING about. Or talk like it.