Expert: Dan Liddy - 4/22/2004

Question
I have been planning on doing some mini stock racing for a while now.  I am new to racing but know cars very well.  The local track will let me race as long as I build a car to meet the rules.  My question is in regards to racing these small 4 cylinder cars.  The rules state a stock 4 cylinder engine.  How much power increase do I need to be able to compete.  I realize this would be a hard question for many reasons.  However, I don't know who to ask and can;t find anything on the internet.  You are bound to make a better geuss than me.  I am sure a stock car and engine would not be competitive.  What is the ballpark figure.  Are the people in small town racetracks increasing power on a car that weighs 2000lbs by 20%, 30%, what?  I see average cars out there racing and I know what those cars are capable of stock.  For example a toyota celica with about 110 hp 120 tq weighs about 2200lbs stock.  What would be realistic if I wanted to take a car like that and race it.  How much performance would I need to get?

Answer
Hi Brian:
When the rules say 'stock' that's what they mean.  They probably allow the use of one specific carburetor, and an exhaust header, but cam must be stock, pistons and rods, valve size - - -all of that. The rules will probably allow you to mill the head a little bit maybe .025" , do that, and do the valve job I mention below at the same time.   That is not to say that there isn't some cheating going on, frequently there is. However, the guy that beats your pants off every week is more likely simply out driving you.   

The best thing you can do is to find a car that seems to be competitive at your local tracks, and get one of them. Don't try to do something 'different'  just yet.  You can prov a point after you have some experience and a bit more savvy.

Other things you can do to increase power are increase the piston to wall clearance, increase the clearance of the rod and main bearings to .002". Carefully set your timing so at full advance it's about 34 degrees BTDC.  Tinker with the distributor until you can make the mechanical advance work faster than stock, and throw away the vacuum advance part.
Also, do a valve job, and ask for a competition "three angle" job. It will cost more, and if done right will gain you a couple of ponies. Look for a race engine shop locally and take all your machine work there.  Ask questions of them, try to learn more.  It takes time- - -It's taken me something like 40 years, so be patient.

Here's the real secret. YOU WILL WIN YOUR RACES IN THE CORNERS ! Go to a book store and ask them to order "How to Make Your Car Handle" by Fred Puhn, it's about $15 and worth 10 times that. Spend your time and money making the car turn left, and learning how to drive it in turns, and make it stick there. Its complicated, and not many grassroots racers understand it well.  If you are better than they are in that area, they'll go home scratching their heads.

That's about all I can offer right this minute, but feel free to send follow-up questions.

Dan Liddy
Sarasota, Florida