Jason's 1990 MR2 project

[JasonFriday13]

So I have starting tidying up some stuff I haven't got round to.

First is chopping these down as they aren't needed anymore. The loop from the idle control solenoid is playing havoc with the brakes as soon as you come off the boost, as in the boost has to bleed off before the booster comes up to help the brakes out, and blocking off the blow-off valve makes it worse. To me that's not safe.


And these will go in soon. Urethane torque mounts with TRD engine mounts .

[Grrrrrrr!]

Problem isn't the idle control solenoid, your check valve in the vacuum line to brake booster is not working, or your brake booster is leaking. Replace which ever is stuffed and your brake problem should go away.

Just looked at toyodiy, and the gen1s have a check valve on the booster, The gen2+ have it in engine bay, up near the firewall.
http://www.toyodiy.com/parts/p_J_1990_T ... 703.3.html

[JasonFriday13]

Well then, that's the problem. Gen 1 vacuum lines with a Gen 2 master cylinder = no check valve. I still have the Gen 2 shell so I will swap out the vacuum line in the turbo for the Gen 2 one with the check valve, well spotted .

[JasonFriday13]

So after just a week and a half I got bored with the CT26, so yesterday I ripped it off and put on the CT20b. The ct26 spooled up at about 2800 rpms, the ct20b spools up at 3000 rpms, and what a difference NA cams with cam gears make . The powerband is just like an NA car, from 5000 rpms up to the redline (75000rpms).

The fuel map didn't go lean like I was expecting it to, so I just tweaked it a bit closer to 12 to 1. I have to get a picture of the log with a second gear pull to redline to show you what I mean .

[85AW20v]

That's a brilliant redline!! It's a wonder it stayed together at seventyfive THOUSAND revs - must have sounded good

[*84vvt]

That's a brilliant redline!! It's a wonder it stayed together at seventy-five THOUSAND revs - must have sounded good

Sell it to a F1 team and retire .

[JasonFriday13]

I got a little carried away there, seventy five thousand revs means no gearbox and no gear changes . Proofread FAIL.

Anyway here's the comparison. I noticed the ct20b has a slightly higher base pressure than the ct26, that could just be a stronger spring. I am hitting low 60's on the injector duty cycle, which suggests a power of about 130 kw on 7 psi. I intend to do a power only run on a dyno at some point just to get a base figure.

The wideband doesn't seem that accurate at some points, so I have ignored most of the spikes and refered to other parts of the log for better info.



Next is a video for the sound, this will go up whenever I feel like it.

[85AW20v]

Is the video of the seventyfive thousand redline sound??? Can't wait

[JasonFriday13]

If it was, it's not a piston engine that's for sure .

[JasonFriday13]

So here's the video. Enjoy.

[youtube]http://www.youtube.com/watch?v=SunCMjMtsVU[/youtube]

After this run I found a tiny boost leak thanks to some old oil in the old intercooler. It's the rubber adaptor flange on the front of the throttle body.

[JasonFriday13]

So yesterday (14th June) the car spent about two hours on the dyno, not detailing the results yet as after talking to the dyno guy, turns out the cams have been setup wrong. It still made 139 kw at 7 psi and 161 kw at 10 psi, so cam adjustments and final tune are still to come.

[JasonFriday13]

Finally got the dyno plots. Boost pressures are 7.5 psi (blue) and 10 psi (red).

Power and torque:



Power and AFR:



Power and boost (boost tube wasn't hooked up for 7.5 psi):

[pureadrenalin]

were these in 4th gear Jason?
That's an unusually flat torque curve for a 3SGTE

[JasonFriday13]

No, that's 3rd gear.

Yeah, I am using NA cam shafts which are staggered in duration and lift. The torque is relatively flat while power peaks at the top of the rev range, rather than a standard turbo cam setup which makes all it's power in the mid range and torque drops off after the turbo spools up.

Here is a comparison graph of the two different intake types, same cams. The blue line is the stock gen 3 NA runners, while the red line is the gen 3 turbo manifold. I reckon by increasing the volume of the plenum on the turbo intake, I can stop the torque falling off at the top end and make a bit more power.

[mickeyduck]

Yeah, I am using NA cam shafts which are staggered in duration and lift. The torque is relatively flat while power peaks at the top of the rev range, rather than a standard turbo cam setup which makes all it's power in the mid range and torque drops off after the turbo spools up.

Interesting. I'd heard that the turbos tend to fall away a bit at the top end. Good on you for having a stab at a fix. Nice

Be interesting to see how it compares to a standard turbo in a straight out drag race. I guess the other thing is how does it feel in a dose of serious cornering?