Chris' '90 Toyota Celica All-Trac Turbo (aka "The Shuttle")
Summer '04/'05 Mod List
Updated: July 22, 2021

Oh gosh. Where do I begin..?  The Shuttle has brought me a lot of fun and enjoyment over the past year.  It runs like a scalded dog, and frequently kicks serious butt on some pretty high-powered cars.  Most recently, I was tooling back from the drag strip back in late June when I happend upon a new Porsche 911 Turbo.  I was probably going about 5 to 7 mph faster then him in the next lane over.  As I passed him, I sort of blipped the throttle in a manner which allowed the BOV to do its "psssssssshhhhh" thing.  For many months, this little procedure has become my favorite way of saying, "Hey bud.. You think that's fast?"   Mr. Porsche took the bait and responded with a downshift and his foot to the floor.  Suffice to say, we ran three times from 70 to well over 140 mph and each time he was about 10 to 12 car lengths behind me.  (I'd be more accurate but it's a bit difficult to judge distance in the rearview, especially at that speed.)  It was all I could do to keep from laughing when he pulled along side again for try #4..  He hit the gas; I didn't...  I chuckled and told my g/f riding with me, "I bet he won't tell his Porsche friends about this."  She was not amused, but I was already LMAO.  ;-)  Ok, back to mods..

Here's what's going on... And, just perhaps...
  • larger injectors - the 720s are nearly maxxed with a base FP of 43 psi.


I've Got a Head-ache.  As a few of you know, the engine in The Shuttle has been suffering from a mysterious syndrome whereby the valve lash disappears.  I've adjusted the lash twice, and each time had to machine the 1ZZ buckets between .002" and .008" in order to regain adequate valve lash.  The first go-round I had to adjust both the intakes and exhausts, but the second time I only changed the intakes..  For those who are unaware, when lash disappears, valves never fully seat.  And without good sealing of the valves, several things start to go awry.  For one, performance suffers because combustion gasses leak past the valves rather than exerting pressure on the piston.  Secondly, the engine starts idling like it has some massive long duration cams with a lot of overlap.  Unfortunate for me, the lash disappears very gradually so the changes are neither obvious nor sudden.

So, I drove The Shuttle to Alamo and decided to pull the head.  To make a long story short, I decided to drop the engine trans out of the car because this is somewhat easier (How long is a piece of string?) to me than pulling the head with the engine still in the car. 

Ok, we get the head off the engine, and start disassembling it.  Actually, first I checked the existing lash: the exhaust valve lash seemed to be within spec (.008" - .010") but all the intake valves were out of spec (.006" - .008") and several had ZERO lash and were not closing completely.  Amazingly enough, in this condition and at 22 psi, the engine dynod a pretty flat 400 WHP from 5500 to 8000 rpms just before I dropped the engine/trans.  There's no telling how well it'd run if the head was not all screwed-up.

After disassembly, it became clear the valves were sinking into the head.  Some of the intake valves are cupped so badly on the valve facings that they are nearly razor-sharp around the head of the valve.  I've shipped a few of the valves to the valve manufacture, and will post a write-up on their response when they make a determination on whether or not the fault was/is with their valves.  I can tell you they are a major valve manufacture that is widely known and used.  And, much like ARP, I'm confident in their desire to make right the wrong caused by their part, if their part is found to be defective.  In the meantime, I have another cylinder head being ported and prepped, and it's due to be completed in a couple weeks.

Update - November 15, 2004

The new cylinder head has corrected the valve issue, and the car is running great at w/g pressure of 16 psi.  Due to time constraints, I've been unable to do any significant tuning since installing the new head a couple weeks ago.  However, I'm headed to the dyno on Friday the 19th, where I plan to tune back up to 22 psi.  Stay tuned!

JUN Intake     Update - May 23, 2005

Some of you may be aware that I purchased a JUN intake late in the summer of '02 only to find it fouled the firewall.  As a result, I have a lot of people want to buy it from me, but I've instead placed it under my mattress in the hopes that the Intake Fairy, Mother Nature, or God himself would magically change the intake so that it would fit. Well, it's been two years and no such luck.  So, when the engine goes back in, it'll go in sans the intake manifold so that I can modify the runners to pull the plenum forward about 25 mm, or whatever distance is needed to gain adequate clearance between it and the firewall.  Yes, me, the TIG machine and my grinder have some work to do. 

I attempted another test fit of the intake to precisely assess the work necessary to fit the JUN intake.  Net-net, I'll put it up for sale soon.  It'll take way too much effort to make it fit.

Kumho Tires SUCK!    Update - June 19, 2005

There ya go.  My opinion on Kumho tires.  They may look great, and for normal, non-spirited driving, they're ok.. much like any other tires.  But pushed to provide some grip at the drag strip or in the corners, they simply suck.. big time.  So, I've been looking at my options and in particularly street slicks.  Unfortunately, neither Nittor nor BFG produce a DOT-approved street slick in 215/40-17.  So, I'm left with a few options...  stick with this size, switch down to a 205/40-17 or up to either a 215/45-17 or 225/40-17. At this point, I'm inclined to go with a 215/45 tire becuase its added height will cut effective gearing which will hopefully eliminate so much first-gear tire-spin on a hard launch.

The Shuttle now wears Michelin Pilot Sport PS2 tires in the size of 225/45ZR17.

As always, I solicit your feedback via email on the above.