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

[n1ckz0r]

^ +1

6gc.net, killing 1 dream at a time.

yea thats about right...lol
i understand that my goals are a little far fetched. I never said ANYTHING about 200WHP out of the motor, if you read carefully i specifically said i didnt want 200 WHP. I am still wondering if anyone has dyno numbers of they 7afe with anything over 100 whp?

I lol at your avat. ANON?

[95st-celica]

sounds good man...good luck...you should be able to squeeze 125 hp out of that i would hope

[laff09]

Whatd it cost you? and when are ya going to get it dyno'd?

[Bricy]

you should look into a set of webcam regrinds, Hurley had some put in her 7a with great results.

[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+

[94celicadude]

^^^^^

wow thank you so much for that information, i have been dying to find out what the stock specs on the cams are but have not had the chance to measure them. This will help me out a lot in possibly obtaining a reground cam and getting better power out of this motor.

Thanks all for the positive comments, i just got a call today that the bottom end was done so i will pick it up tom. and start the reassembly process, i will try to take lots of pics in order to show my progress. Ill let you all know how it is going as soon as im done, hopefully the engine will be back up and running within the next two weeks. Wish me luck

Matt

[Bricy]

Good Luck! I know all of us 7a peeps are rootin for ya!

[Bitter]

well, i had to stay only with the first oversize pistons because the class i run in auto-x allows for only the first over size. Thats the main reason that the CR is stayin close to that, and for cams, i do not yet know but i think that im going to try to get a set of cams reground and possibly play with that for more power, but for the moment i am staying with stock cams.

you can get a higher CR with 4age pistons that have been modified slightly, without going over on the bore beyond your class specs. remember than the 4afe, 7afe, and 4age share the same bore diameter.

[94celicadude]

Well i got the bottom end back today, i think the pics are pretty self explanatory. If you have any questions just ask!


Balanced Flywheel and Pressure Plate


Cleaned Intake Manifold


Hole created to remove "casting wart" (I have to weld it on the weekend, ill post a pic of it shut


Close up of said hole


SHINY!!!!


New Water Pump


More shiny/clean pieces


Its truly a lot smaller than you would think


Bottom End Already Assembled


Shot-peened Rods (dunno bout spelling)


New pistons, bored cylinders, decked block


New valves, machined intake valves, balanced/polished combustion chambers


Close Up shot of the exhaust port, that is how smooth the extrude hone process makes it, better than just PORTING!!


Shimming valves


Notice matching marks on cam gears. Its a factory mods


Both cams in and bolted down, all valves shimmed to proper clearances.

I also just realized that i am going to need to remove the cams again to be able to bolt the head on woops

More pics to come soon of final re-assembly. Wish me luck

This post has been edited by 94celicadude: Feb 13, 2008 - 11:31 PM

[markjbutler]

so clean and shiny!!

Wish I had the space/time/knowledge/another car to drive so i could play with my 3sGE like that

[hurley97]

you're doing all that head work and putting the stock cams back in? that's a shame.

it's also a good idea to replace your starter before you put the engine back in the car, it's easier to get to with the engine out.

[zbigb]

If you do add some cams , here is a way to mod your intake for better high end pull. This shortens the intake track and adds a bit of volume to the plenum as well.

[stephen_lee]

If you do add some cams , here is a way to mod your intake for better high end pull. This shortens the intake track and adds a bit of volume to the plenum as well.

would that help stock much? i doubt..

[zbigb]

Probably not. You would loose more low end than you make up on the top end. I would not do this unless you are running some cams with more than stock duration.

[94celicadude]

thnks for all they input.

Hurley, the reason i am putting stock cams into it is because i am trying to increase my power and torque around the midrange of the power band. As in around 2500-4500 RPM.

I do understand that cams would help me out a lot, but i feel that the gain would be mostly up to and i dont want that for specifically one reason, this is an auto-x car, so after i start my racing i go through first and then stay in second for the rest of run, so if my meak power and torque jumps up to around 5000 RPM or higher, the power avaiable to me becomes useless because i will never get that high in the RPM in second, thats reaching around 60 mph and i have rarely ever hit the fuel cut in second gear.

Now i am going to keep my stock cams from my other head and do some work and research to see if i can get a regrind that will in fact give me more power in the midrange.

Once again thank you all for the info and input, wish me luck as i head into the cold garage to put this motor back together.

Matt

[hurley97]

Call WebCams and tell them that, they will find a grind that suits your needs.
When I spoke to them I said my car would be turbocharged eventually, which normally increases power in the mid range so they gave me a grind that would increase slightly overall but kick in around the higher end, this way it holds out the power from the turbo longer.

The reason I say it's a shame to put the stock cams back in is this: you are doing all this work to make your head flow better, however, the head can only feed as much as the cams will let it. If the cams are opening the valves the same as before, you can take in as much air as you want through the intake plenum but the valves are only going to open enough to let in the same amount of air as before.

Basically what I'm trying to say is, yes it will run better and yes the head will flow better, but you aren't going to get the results I think you are looking for without being able to pull more air in through the valves, which you need bigger cams for.

[Bitter]

another good power adder for your midrange (dont know if this would change your auto-x class) is the ebay header. it moves that torque you feel from about 1500 rpm to about 3000 rpm rather nicely. i carve a canyon in 2nd gear and you really stay more in the powerband with the ebay header than the stock cast manifold. heatwrap it to keep your engine bay temps down, it does let out ALOT of heat. also, it weighs about 1/2 the stock part does.

[jason]

i think dustin's dyno shows a little if any gain through the bottom & mid range of the curve, then up high is where the stock fell off where the reground kept rising

like steph said, im sure if you called them for a specific purpose, they could make something for you. the 7a's max torque i believe is right at or around 3,000 so if you are keeping it between 2500 - 4500 anything above 3000 is going to be in the torque falloff part.

so if you were to get them reground, give yourself 15hp extra above 4000 (help on longer straights) keep the same stock torque down low, but add another 10ft/lbs from 3000 - 3500 you should have a descent performance, 10% about over stock - plus your additional mods that i dont believe steph and dustin did. (yes i know his was on a 5s)

i think you should consider getting a spare set re-ground. worse case, sell them to someone who wants a higher top end, and put your stockies back in. playr said he would even donate some to you =)

[Bitter]

actually from what i've seen the 7afe holds peak torque from about 2500 rpm till nearly 5200rpm and then it begins to fall slightly as the HP rises to its peak around 5600-5800rpm.

just because peak torque comes on early doesnt mean it falls off early either.