Ca18det bogs at 3k rpm under load

Discuss topics related to the CA18DE and CA18DET series engines.
Ca18det-mg
Posts: 3
Joined: Mon Sep 27, 2021 12:13 am
Car: 1971 MG ca18det

Ca18det bogs at 3k rpm under load

Postby Ca18det-mg » Mon Oct 25, 2021 9:28 am

I have a swapped 71 mgb with a ca18det in it. I’ve put a ton of work in it. It has a EM-4 ecu and just recently had a t28 turbo installed. Everything is ready to go for a lot of turbo. It has inner and oil cooler. A huge oil pan etc. Engine has extremely low miles and when it had a t25 turbo before it used to get 200 hp. That was probably 10 years ago though it sat alot. I just did new plugs gapped to 27, oil change fixed the down pipe leak with gaskets and spacer. New heated o2 sensor and gauge. It’s not quite ready for the dyno though something is wrong with the actuator on the turbo. I think is one problem for sure. I’ve ordered a boost controller and a new actuator and waste gate. But since the turbo is so big for the space it’s sitting on its side and I can’t get the waste gate and actuator to fit flush with both bolts to the turbo. I may need to make a flange or someway to get more than one bolt on it. But it runs and drives it just bogs hard and pretty much stops accelerating at 3k rpm. If there’s no load on it just sitting in neutral it can rev up really high but once under load it can’t get above 3k rpm in 3rd gear or any gear even with my foot all the way on the gas pedal. I can see the boost gauge never goes above 5 psi which is really low boost. So I’m thinking the boost controller may help but I feel like it should be going above 3k rpms even without boost. Wondering if I’ve got another underlying issue just don’t know where to start. Any help troubleshooting would be greatly appreciated.

https://ibb.co/6WVk3rV
https://ibb.co/dP49118

Also this is a full list of specs from before I fixed it up and put a bigger newer turbo on it.

http://veh-markets.com/cars/rover-mg-c/ ... build.html


Ca18det-mg
Posts: 3
Joined: Mon Sep 27, 2021 12:13 am
Car: 1971 MG ca18det

Re: Ca18det bogs at 3k rpm under load

Postby Ca18det-mg » Mon Oct 25, 2021 10:59 am

Just wanted to show I have all the gauges I need to diagnose a problem. I replaced the exhaust temp with an o2 gauge.

https://ibb.co/X2VMRfJ

User avatar
float_6969
Moderator
Posts: 19787
Joined: Mon Aug 26, 2002 1:55 pm
Car: CA18DET swapped 1995 Nissan 240sx (too many mods to list)
2015 SV Leaf w/QC & Bose (daily)
Location: Topeka, Kansas
Contact:

Re: Ca18det bogs at 3k rpm under load

Postby float_6969 » Wed Nov 03, 2021 7:28 am

Have you contacted SDS about the issue? It sounds like weak spark to me OR you've got noise on the hall sensor input. Could also be weak voltage/bad ground for the coil driver. I had breaking up issues when I first put my SDS in like 20 years ago. It ended up being voltage sag under load. The wire I used for the positive wasn't big enough. At idle and revving in neutral, it would move enough current, but once I got a load on it and the revs increased, it the voltage would drop and it would even blow a fuse from the increased current sometimes. I put a bigger wire on it and it was fine.

Ca18det-mg
Posts: 3
Joined: Mon Sep 27, 2021 12:13 am
Car: 1971 MG ca18det

Re: Ca18det bogs at 3k rpm under load

Postby Ca18det-mg » Mon Dec 13, 2021 8:14 am

:bowrofl: you are the king man thanks for responding. I didn’t want to announce my plan until the parts all came in this stuff is rare. I got a CAS, a harness and a g4x ecu I’m abandoning the sdsefi. My tuner guy said this thing is meant for airplanes and said it’s barely tunable. So I’m going to put in a real after market ecu that has a usb that has graphs and everything so he can properly see what’s happening and tune it appropriately. Just dropped like 2k plus I hope this is worth it. Gonna be a fun Xmas getting this harness from a 200sx into my mg. Haha wish me luck I’ll post back here with my Dino results

dash
Posts: 575
Joined: Fri May 05, 2006 4:07 am
Car: s13 ca18

Re: Ca18det bogs at 3k rpm under load

Postby dash » Fri Dec 17, 2021 4:57 pm

My tuner guy said this thing is meant for airplanes and said it’s barely tunable.
Airplanes "should" be pretty reliable, ya think ? :chuckle: I'd want that in my car
Barely 'tunable' ? Dunno about that.
My neighbour swapped a toyota 7Mgte into his 91 240sx. Tach swung round to redline while pinning you in the seat
Car skating all over the road, roasting tires for the 1st four gears! Not a hiccup. Smooth as silk
Upgraded stock CT26 turbo/T4 compressor. SDS he self installed & tuned(his 1st standalone)
What more is there ? He did have some teething problems, and yes the SDS can be finicky sometimes

User avatar
VStar650CL
Posts: 5366
Joined: Thu Nov 12, 2020 1:25 pm
Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

Re: Ca18det bogs at 3k rpm under load

Postby VStar650CL » Fri Dec 17, 2021 8:27 pm

dash wrote:
Fri Dec 17, 2021 4:57 pm
"should"[/i] be pretty reliable, ya think ?
Not necessarily in a car. Keep in mind that a typical general aviation piston engine still has a magneto ignition. Ancient but utterly reliable. In many ways aviation is a completely different world. In a car you armor the passengers with airbags and crumple zones. In a plane you can't afford the weight of armor, so you endeavor to prevent any crash in the first place.
;)

dash
Posts: 575
Joined: Fri May 05, 2006 4:07 am
Car: s13 ca18

Re: Ca18det bogs at 3k rpm under load

Postby dash » Sat Dec 18, 2021 12:26 pm

so you endeavor to prevent any crash in the first place
and that's the point, so you choose something as equally 'utter reliable'.... like a SDS ecu
If it gets a hunk of metal in the air, keeps it there, then safely returns..... Not good enough for automotive ?
Your tuner seem to think aircraft grade is a bad thing
Barely tunable is nonsense as well
Show him our resident CA18 gurus' hi strung CA18 street cars. SDS tuned (barely :naughty: )


Return to “CA18DE / CA18DET Forum”