Spec V kit - draw-through / blow-through conversion

mjeffries · Tweet this Post! #1 (**permalink**) 06-21-2006, 08:26 PM

Is there a specific reason the Spec V kit is designed as a draw-through system? I own the book "Maximum Boost" by Corky Bell but he only talks about the differences of draw-through / blow-through on carborated engines. Would converting the system to a blow-through system have any adverse effects on performance or reliability?

http://myspecv.com/f/view_topic.php?id=23

Thank you for your time.

Robert · Tweet this Post! #2 (**permalink**) 06-22-2006, 02:40 AM

Quote:

Originally Posted by mjeffries

Is there a specific reason the Spec V kit is designed as a draw-through system? I own the book "Maximum Boost" by Corky Bell but he only talks about the differences of draw-through / blow-through on carborated engines. Would converting the system to a blow-through system have any adverse effects on performance or reliability?

http://myspecv.com/f/view_topic.php?id=23

Thank you for your time.

Well it would. The short of it is the Spec V MAF is not capable of handling the increased air flow for a long time. Thats why you see so many turbo Specs blowing MAFs. Secondly with the Unichip installed there would be no benefit at all to running blow through. The Unichip 100% intercepts all signal from the ECU out to the motor and alters them based on the applied tuning map. At low boost/throttle position the ECU is running the car with some minor correction by the Unichip. Aside from that the Unichip is 100% running the timing and fuel. If you did run blow through the piping diameter would have to be the same for the MAF which did not work so well since the stock piping was not the right size for the amount of air flowing through the motor with the turbo. In short there were quite a few reasons for doing it this way. It was tried both ways, this was found to be the best, and most reliable way to do things.

kgkeen101 · Tweet this Post! #3 (**permalink**) 08-09-2006, 02:09 PM

Just a few questions from a guy just getting into cars, whats the difference between a blow-through setup and draw-through setup and what does MAF stand for? WHat are the pluses and negatives of a blow-through and draw -through setup?

Robert · Tweet this Post! #4 (**permalink**) 08-09-2006, 03:18 PM

Quote:

Originally Posted by kgkeen101

Just a few questions from a guy just getting into cars, whats the difference between a blow-through setup and draw-through setup and what does MAF stand for? WHat are the pluses and negatives of a blow-through and draw -through setup?

He is referring to whether boost is pushed through the MAF or if the MAF is placed in front of the turbo and air is pulled through it into the turbo. There are several advantages and disadvantages of each way. The best thing to do is pick up the book Maximum Boost by Corkey Bell. It should answer most of your questions.