Max Power NA 7afe ????, Dyno Charts Posted Options

[94celicadude]

Hey all,
I am currently building up my 7afe, i have bought a separate head and have already had new valve guides installed, its been cleaned and i have brand new toyota valves, exhaust and intake, i have had the intake ones machined to have more of the performance "penny on a stick" figure, i will post pics soon but for now here is an example Valves.

I am also going to have the Extrude Hone process ( Extrude Hone ) done to the entire head. The current 7afe in my car has a custom 4-1 headers (Headers), full exhaust, intake, clutch, lightweight flywheel, Apexi S-AFC II, bumped timing to about 14 degrees static timing. If i can find a used GT throttle body i will try to make it work, they seem to be fairly similar. Its been tuned and it has over 225k miles on the original engine. The gear box has been rebuild to brand new, and at last dyno the car was putting just about exactly 100 WHP on a 95 F day.

So i figure its already a healthy working little motor. To make this short, i was wondering who has had the highest NA horsepower out of a 7-afe . I am hoping to be able to build my motor to about 120-130 WHP, that would be ideal but im not sure exactly if i will achieve that goal. The bottom end is going to get first O.S. pistons, the head will be decked for a slightly higher compression ratio, and the entire engine will be blue printed. Then the entire crank assembly will be dynamically balanced with the flywheel and all the accessories on either end of it. Then it will all be put back together and have another tuning session on the dyno.

Now i know that it seems like a lot of money to do everything i am, which it is for only 130 WHP, but im looking to make this a great motor for auto-x. And if i have 200 WHP then ill just create a smoke show, so thats why im not just swapping in something else.

**CLIFF NOTES**

Who has the highest NA power 7afe with dyno numbers to prove it?

This post has been edited by 94celicadude: May 9, 2008 - 5:27 PM

[playr158]

I'll donate an extra set of stock cams for a regrind just to see what it does

[zbigb]

I’m following your progress with interest. I am researching the 7AFE in NA form because I am planning on building one too. I have not found much about how these engines respond to bigger cams. I just finished measuring the specs on a set of stock cams from a 1994 Corolla 7AFE and was shocked to see how short the duration is.

Intake 147 degrees @ .050
Exhaust 151 degrees @ .050
Overlap at TDC is less that .020

I have built up lots of different engines over the years and have never seen a cam with such short duration. For this engine to make the power it does with this small of a cam says a lot for the tuning Toyota did. It also says a lot for the combustion chamber and ports. The combustion chamber benefits from being so small and shallow. The fast burn produces lots of torque. You can get high compression with dished pistons and still run on pump gas. If you are doing a rebuild, the Toyota 4AGZE piston can be used to get a good bump in compression. The port design is excellent, and looks very much like the port that was used on the Formula 1 engines. Small, but very straight allowing for high port velocity = wide power band.

I have recently spoken to several cam grinders. I have not found anyone that can get new cores for the cams. This is probably why not many people have been camming the 7A. I found a few cam grinders that will regrind your stock cams for $200 to 250 a pair. These are not welded, so you need to use lash caps under the cam buckets. You can also get welded regrinds for $300 – 600 a pair. You have to be careful with welded regrinds as the process is much harder (easier to screw up). A poorly done weld and cool down process leaves you with a cam that is bent or tends to bend after running.

It is likely that you do not need a big change in duration to feel a difference. The down side of changing the cam is that tuning the engine will likely get way harder. When you change the cam timing, you will need to start the tuning process all over to get the spark timing and a/f correct.

Good luck with your build up and hope you get 130+