My truck, a work in progress
Wednesday, October 17, 2001
  Part 7: Back on the road (10-17-01)

Well, after almost exactly one year and a boat load of money, I finally have the engine back on the road!

Here are a few shots of the beast:







I gotta say, it came out as nice as I had hoped it would. It just took an impossibly long time to get this truck to this state, and there's still a lot more to be done.
But first, some initial dyno numbers:

Max HP, as measured at the rear wheels: 206.1 @ 4600 rpm
Max torque, as measured at the rear wheels: 250.4 ft. lbs @ 3300 rpm.
All measurements at 12 psi boost


OK, so I'll admit that I was hoping to see 300 hp straight out of the blocks, but actually these numbers are pretty respectable, as I still have a lot of tuning ahead of me. But these numbers are in the ballpark, and, assuming a 20% driveline loss, come out to 240 hp and almost 300 ft. lbs. of torque at the crank.

The good news is that the truck is remarkably streetable: it drives very nicely, and moves very quickly when you put your foot in it. The bad news is that it should be making more power than it is, and I'm not sure why it isn't. Of course, it will make more power if I turn up the boost, which I intend to do once I get a better handle on the fuel table. But I think it should be making more power now, at 12 pounds of boost, and I have a couple of theories as to why it isn't.
Theory #1: The exhaust is now undersized. When I get a scanner and post the first dyno results, you'll be able to see that the power curves sort of taper off. This is unusual for a turbo engine, as you'd expect it to keep making more power the faster it turns. So one strong possibility, in my opinion, is that the 2.5" exhaust is just getting too choked up to flow adequately above 200 hp. I'll be taking care of this straight away, as I have ordered the parts to make up a mandrel bent exhaust out of 3" 304 stainless steel, with a new 3" magnaflow cat and "Wide Open" muffler. I hope to have this in before the end of October.

Theory #2: I have some cam issues I need to resolve. I may have some problems with my cam timing, and/or my cam is simply not optimal for a non-stock EFI system. I have a degree wheel on order, and hope to get to the bottom of this real soon. I may also swap out the DOA C270 cam in favor of a CompCams 260S, which has a longer intake duration (while still being basically a truck cam). Again, I hope to get to this real soon, as i'd like to do some more dyno testing in the coming weeks.

So that's where things stand right now. Mostly, I just need to spend some time driving it around (I have less than 200 miles on the engine with the new turbo and all the other goodies). So look for a more detailed update in the next week or two, once I have a better grasp of what the motor is doing. 


The ongoing saga of my 1986 Toyota 4x4 truck and its much-modified 22RTE turbo engine.

Return to my table of contents

ARCHIVES
12/01/1999 - 01/01/2000 / 01/01/2000 - 02/01/2000 / 10/01/2000 - 11/01/2000 / 11/01/2000 - 12/01/2000 / 12/01/2000 - 01/01/2001 / 01/01/2001 - 02/01/2001 / 03/01/2001 - 04/01/2001 / 08/01/2001 - 09/01/2001 / 10/01/2001 - 11/01/2001 / 12/01/2001 - 01/01/2002 / 01/01/2002 - 02/01/2002 / 02/01/2002 - 03/01/2002 / 12/01/2003 - 01/01/2004 / 02/01/2004 - 03/01/2004 / 04/01/2004 - 05/01/2004 / 05/01/2004 - 06/01/2004 / 04/01/2007 - 05/01/2007 / 07/01/2007 - 08/01/2007 /


Powered by Blogger