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Discussion Starter #1,161
I just missed an 83 Cressida on Craigslist for cheap. After some reading it seems that the 83/84 Cressida shared a lot of parts with the Supra. Rockauto confirms identical suspension parts in some cases and the engine compartment looks very familiar. A trunk would make a great bulkhead for separating the fuel system and diff cooler from the driver compartment, and they have 18.5 gallon fuels tanks!

I'll keep racing the Supra for now, but I'm on the hunt for a Cressida to look at in person and do some measuring.
 

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I don't think a Cressida would make a better race car. I think they are heavier and you can't put as wide a tire on them. Couldn't you modify the stock intake manifold to stay low cost?
 

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We've been running an 86 cressida, and love it, the extra fuel allows us to run 2.5 hours fairly comfortably, many parts are interchangeable with the Mk2, whole drivetrain, suspension. the rear arms I understand are a tad longer, I'm told by the previous owners who are classic toyota guys that if you put supra arms on the cressi, you will get an extra degree of camber for those that are looking for more "stance"
I do feel the aero brick that is the cressida does hurt a little on the longer straights, but nothing to compare it to.
as far as weight, our car is about 2800lbs wet moderately lightened with a basic lemons legal cage.
 

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Discussion Starter #1,164
The 83-84 Cressi was 200 lb lighter than the 1986, so I'll bet it could get close to my Supra weight (2540). I'm sure that I could find a way to get 245 or 255 rubber underneath it. The Supra will live on for now as it's getting close to complete, but I'll be keeping my eyes open for a Supra or Cressi shell to use as a new foundation.
 

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Discussion Starter #1,165
Have you ever gotten to the point of a budget build and faced insurmountable problems that make you ponder throwing in the towel? That was me two months ago as I fought with trying to package 10lbs of crap in a 5lb space, while also sacrificing a bit of safety by cutting a large hole in the firewall right in front of the driver. Competing for space: Intake pipe, Throttle body, Fuel line, Brake line, Throttle cable, Coolant hose, and Firewall.




After trying everything in my skill set to make this work I finally gave up at the exact moment that the answer was being crafted. Rather than giving up I changed my thought process. I want: 1. safe, and 2. reliable, so I spent some money to solve all of the problems. Yes, I'll take a hit and who knows where the Chump budget will end up, but I'm ready to finish this thing the right way.

New Hotness: KMiata intake for RWD applications. Uses K series IACV and MAP, a B-series throttle body and TPS (found used on eBay). I was able to weld the firewall closed, and there is a ton of room for all components.






The search is on for a Toyota throttle cable that will fit, and a plug for the B-series TPS. Then it's dyno time.
 

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Discussion Starter #1,167
After some more creative fabrication (throttle cable, cooling hoses, brackets) it was time to start the car again last night. It fired up quickly and everything seemed to be OK. So today Grumpy Butt saw daylight for the first time in 18 months. I added water to the cooling system and tidied up a bit in the engine bay, then started it outside and tested the clutch. So far so good, so a quick blast down the street verifies that the drivetrain is functional. So far there are no water or oil leaks.



A gauge check after the first blast down my street. Good oil pressure and the alternator if working.

https://youtu.be/NRv0enidxU0
 

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Awesome! This is a hell of a swap, very curious how its going to perform.

That was a long haul, it always hurts having your baby off the road for so long. Mine has been in storage for the last year, hoping to drive it again relatively soon (spring at latest).
 

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Discussion Starter #1,169
Dyno time.

After a few teething issues the K24 is running well in its new home. The torque curve is quite different than the inline 6 cyl!

I'll upload video of a run when I figure out how to get it off my phone :lol:




 

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What do you mean by "real"? The car made about 60 pulls across 3 days of tuning but someone had messed up the graph axis markings. The numbers for peak tq and HP were 140 and 180 at the axles. I believe there's something wrong because this engine is supposed to pump out 150+ lb-ft of torque from 2500rpm and not have a dip in the curve. Still trying to track down the issue (checked cam timing, VTEC, VTC angles, compression, plugs).
 

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Discussion Starter #1,174
That thing sounds so wrong but I love it! ...looking forward to seeing how the car does for you without that extra 150 pounds on the nose!

--billyM
I'm going to miss the smooth I-6 sound for sure! And the boatload of torque from low rpm.
 

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What do you mean by "real"? The car made about 60 pulls across 3 days of tuning but someone had messed up the graph axis markings. The numbers for peak tq and HP were 140 and 180 at the axles. I believe there's something wrong because this engine is supposed to pump out 150+ lb-ft of torque from 2500rpm and not have a dip in the curve. Still trying to track down the issue (checked cam timing, VTEC, VTC angles, compression, plugs).
Like a printout with legible engine RPM numbers and Torque and HP figures on the sidebar so we can tell what we're looking at :)

Thanks for the extra info, only the peak torque was listed on the screen photo. The computer read out at dyno shops is always missing a bunch of that info.

Curious what this thing weighs now!
 

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Discussion Starter #1,176
No paper copy, but below is the final tune and graph (solid lines). The dyno was rebooted to get the numbers back to the correct scale. I have a track day scheduled for December 6th at Road Atlanta, a friend is bringing scales so I'll have the current weight soon. The only time it was weighed it came in at 2450 lb with all fluids but no driver. I would love to see a number under 2350. The mass is also more centralized with 95% of the engine weight behind the front wheel bearings, so the distribution should be much better.



I've been scouring the internet for tuning information about the K24 and might have found a reason for the low torque at low rpm. The VTC (like Toyota VVT) is also supposed to be advanced on the low cam profile and we have the VTC set at 0 degrees until VTEC hits. I will try adding some cam advance at low rpm to see what happens.
 

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Discussion Starter #1,178
Did you find the "Honda" written on the engine?
Bwah ha ha ... well played, sir!

"For a Honda" this engine actually produces reasonable torque when the iVTEC systems are working properly (150-160 lb-ft from 2500rpm). It's not the monster 175 lb-ft of the 6MGE, but good enough for a race car.
 

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Yeah if you can fill in that big dip before 5000rpm it should be pretty respectable. Your curb weight is awesome, hundreds better then you could do with any Toyota inline 6, lets see if you can get your torque output up to those ranges! Thanks for posting a real graph!
 
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