Power loss - Toyota Nation Forum : Toyota Car and Truck Forums

TRDemon · 08-30-2004, 01:28 PM

I seem to be lossing power @5000rpm with 4A-F did anyone have this problem. just wondering if this is the norm.

Ukrainian102 · 08-30-2004, 08:01 PM

The torque peak for the 7A-FE if I remember correctly is ~2,400 rpm. Should be close to that on the 4-AF. Maybe that's why.

Flashmn · 08-30-2004, 10:43 PM

4A-F gets peak power at 6000rpm.

***Chris Corolla S*** · 08-31-2004, 12:03 PM

Quote:

Originally posted by Ukrainian102
The torque peak for the 7A-FE if I remember correctly is ~2,400 rpm. Should be close to that on the 4-AF. Maybe that's why.

No.

Pineapple · 08-31-2004, 12:09 PM

Torque at 4800 for 4A-FE.

Dragcrxsi · 08-31-2004, 12:18 PM

Quote:

Originally posted by Ukrainian102
The torque peak for the 7A-FE if I remember correctly is ~2,400 rpm. Should be close to that on the 4-AF. Maybe that's why.

That sounds way off

Ukrainian102 · 08-31-2004, 02:30 PM

Sorry, 7A-FE is 2,800 rpm torque peak, much lower than the 4,400 rpm of the 4A-FE. Useful for smoking everyone off-the-line and hauling groceries uphill.

Check it out here: http://www.corollaperformance.com/Te...dex.html#specs

***Chris Corolla S*** · 08-31-2004, 04:28 PM

Cool I have a link that says stuff too, who knows what it is

This has an AE102 4a-fe with a TQ Peak at 3,000 RPMs:
http://autos.msn.com/research/vip/sp...IP&tab=2&sub=1

This one has the 7a-fe at 134 ft-lbs of Tq

http://autos.msn.com/research/vip/Sp...IP&tab=2&sub=0

But this one supports the 2,800 RPM claim for the 7a-fe:
http://www.geocities.com/MotorCity/P....html#A-series

To get back on topic the above link also shows that the 4a-f has peak HP at 6,000 RPMS (90HP @ 6,000, 95lb-ft @3,600) so it should be screaming at 5,000 RPMs not slowing down.

Ukrainian102 · 08-31-2004, 09:03 PM

Don't trust MSN Autos. They don't have the right ground clearance listed for my friend's MPV. (Long story, we were having a bet on something.)

Also MSN autos says torque for a 93-94 DX is 134, but it suddenly drops to 110 in 1995!

Kwanza · 08-31-2004, 10:13 PM

Quote:

Originally posted by Chris Corolla S
Cool I have a link that says stuff too, who knows what it is

This has an AE102 4a-fe with a TQ Peak at 3,000 RPMs:
http://autos.msn.com/research/vip/sp...IP&tab=2&sub=1

This one has the 7a-fe at 134 ft-lbs of Tq
http://autos.msn.com/research/vip/Sp...IP&tab=2&sub=0

But this one supports the 2,800 RPM claim for the 7a-fe:
http://www.geocities.com/MotorCity/P....html#A-series

To get back on topic the above link also shows that the 4a-f has peak HP at 6,000 RPMS (90HP @ 6,000, 95lb-ft @3,600) so it should be screaming at 5,000 RPMs not slowing down.

The reason for the power/torque decrease on the 7AFE is emissions related... and they did decrease a bit... although 134 ftlbs is an exaggerated number (110-115 ft lbs is about right)... and the max torque does peak in the 2500-2800 rpms range, depending on who you're asking.

As for the 4AFE, it's an undersquared motor, which a short stroke so torque peak will be higher in the rpm band... even with the FE head. It delivers a fairly flat torque curve till it peaks, then drops off rapidly. Anyways... hardly "screaming"... but it'll get you from point A to point B... ;]

Flashmn · 09-01-2004, 09:35 AM

4A-F and 4A-FE have different cams, 4A-FE peaks at slightly below 6000, (somewhere near 5600) and the 4A-F at 6000

jayboogie · 09-01-2004, 08:22 PM

its the same with the 4a-ge.

since its my daily driver and i want to conserve gas i shift @ 4k most of the time.

its extremely weak before the 3500 rpm mark... then right after that i feel a very strong pull - that's my que to shift

'

also, try putting some Chemtool in your gas tank... it helped me a lot.