Turbochargers on Stock cars

[Greg Hogue]

I have been trying to get this clarified as to the rules. I am putting a Stocker together to run in AF/S its one of the Mopar 2.5 liter Turbo cars.
Doing this for my Jr Dragster racer and maybe myself. She is aging out of Jrs. I do not want to waste a good bottom bulb foot brake on Super racing or Top dragster.

here is the only mention of turbos in the rules.
TURBOCHARGERS
Turbocharger size will be verified by measuring the housing bore at
the leading edge of the impeller wheel. The maximum diameter of the
housing bore at the leading edge of the wheel may not exceed 2mm
more than the maximum allowable turbocharger size permitted

There is no casting numbers or types of turbos, just the inducer and leading edge of the compressor wheel size limets

The index is 13.85 and the car can run easily as fast at you let it. I plan on giving her .50 under tune. Can you be competitive at 13.35 in Stock

[GTX JOHN]

As long as you can run under the index (.3 to .4 ) enough
to account for extremely hot weather or poor track condition - you are
competitive! Not a bunch of cars in that class = Not many Heads Up
races to contend with in that class.

[Mark Yacavone]

Originally Posted by Greg Hogue

I have been trying to get this clarified as to the rules. I am putting a Stocker together to run in AF/S its one of the Mopar 2.5 liter Turbo cars.
Doing this for my Jr Dragster racer and maybe myself. She is aging out of Jrs. I do not want to waste a good bottom bulb foot brake on Super racing or Top dragster.

here is the only mention of turbos in the rules.
TURBOCHARGERS
Turbocharger size will be verified by measuring the housing bore at
the leading edge of the impeller wheel. The maximum diameter of the
housing bore at the leading edge of the wheel may not exceed 2mm
more than the maximum allowable turbocharger size permitted

There is no casting numbers or types of turbos, just the inducer and leading edge of the compressor wheel size limets

The index is 13.85 and the car can run easily as fast at you let it. I plan on giving her .50 under tune. Can you be competitive at 13.35 in Stock

That depends a lot on the driver. It IS a stick car , right?
Turbo cars aren't the easiest or most forgiving cars out there, in my experience.

[oldskool]

"As long as you can run under the index enough (.3 to .4 ) enough to account for extremely hot weather or track condition you are competitive!..."

Now ain't that simple !

No, I don't have a dog in the hunt.

But, I did some Stocker racing & quite a bit of bracket racing, back in the old days.

I just don't understand why so many Stock/SS racers seem to take offense when anyone compares their kind of racing to bracket racing.

It's just a simple fact that if you have a legal car that can run the index, at a race, that car can win that race, provided they don't have a heads-up round.

Unless there are a large number of cars in your class, in aprox what percentage of races will you have a heads-up run ?

Just a casual observation would be that if ONLY the cars that can run more than a sec under had a chance to win, class racing would cease, quickly. Wouldn't be enuff cars left to support the class.

So, if you have the funds to build or buy & maintain a quick car that can win heads-up runs, great.

But, it might be a good idea to welcome & encourage those with lower budget, slow cars, in order for class racing to continue.

Just as bracket racing saved some of the smaller tracks, the index system, with breakout type racing, has allowed Stock/SS racing to continue now for quite a few years.

This is strictly my own observation & opinion. I have no quarrel with anyone who has a different opinion.

[Billy Nees]

Originally Posted by oldskool

This is strictly my own observation & opinion. I have no quarrel with anyone who has a different opinion.

Hoo Boy, good thing for that or your barn would be burning down.

[Greg Hogue]

This motor class is soft. It’s capable in close to stock tune with a tune over a second under. I just want to make a race car out of it and not a side show. The big question is what is the turbo rule. The way it’s written the only rule is inducer size.

[MR DERBY CITY]

Originally Posted by Greg Hogue

This motor class is soft. It’s capable in close to stock tune with a tune over a second under. I just want to make a race car out of it and not a side show. The big question is what is the turbo rule. The way it’s written the only rule is inducer size.

Your greatest CHALLENGE with this combo is CONSISTENCY ……

[Sean Marconette]

The turbo needs to be the same one that came on the combination you are claiming. NHRA has more info than what they post, you need to contact your division tech director to get that info. To get consistency it takes work.

[Buick6]

If you look up the NHRA technical specs for that engine there should be additional specs for the turbo such as the compressor wheel size. No mention of other specs such as number of fins, pitch, compressor housing A/R, etc.

[Greg Hogue]

Originally Posted by Buick6

If you look up the NHRA technical specs for that engine there should be additional specs for the turbo such as the compressor wheel size. No mention of other specs such as a number of fins, pitch, compressor housing A/R, etc.

that is the way I'm reading it, The inducer size stated is 1.70, and wheel at inducer break is 1.68. There is no other spec, The way I'm reading that is any turbo goes as long as the inducer is the spec size.
The one part I am not clear on is the 2 mm over. Is that 2 mm over the stated size or is that size with the 2 mm added.