Search found 957 matches

by PL
Mon Apr 11, 2022 4:14 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Can be a bit touchy with bigger cams. Should be OK with 258's though. I usually just increase Latency a bit to richen them up. Either that or you can use your TPmin. Ideally you'd increase TIM but that will then affect full load mixtures too. Often increasing TPmin will give most stable idle mixture...
by PL
Sat Jan 15, 2022 10:56 am
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Yes you can adjust TPmin and see if that's holding your inj pulsewidths artificially high. If it's idling nicely though I wouldn't touch it. SR's prefer to idle a bit rich. Once they go to stoich they'll often get a bit unstable. Nicer idle at slightly richer. Particularly sensitive to this if you h...
by PL
Fri Dec 24, 2021 12:02 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Also it'll trim mixtures slightly richer if it thinks things are too lean in the closed loop area.

PL
by PL
Fri Dec 24, 2021 12:00 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Yeah it's a bit lean in some of those cells but that may just be a measurement anomaly. And momentary lean at low load won't hurt it anyway.

PL
by PL
Thu Dec 23, 2021 12:47 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Is it driving OK? If it is then I wouldn't touch it.

PL
by PL
Mon Oct 25, 2021 8:30 am
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Looks pretty good to me. You might wanna take a couple of degrees out of that last column so if boost increases it'll pull timing out.

PL
by PL
Sun Oct 24, 2021 12:18 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

SR turbo engines are knock limited in all but the mildest of tunes (or when running E85). So tuning often comes down adding timing til they start to knock and then backing it off a bit. So monitoring knock is critical. If you try to tune them by watching torque on the dyno and tuning for peak torque...
by PL
Sat Aug 28, 2021 12:55 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Yeah that's not bad. They seem to be capable of being tuned for decent fuel economy on cruise. They do quite well for an old low compression engine. You'll never get great figures around town with lots of start/stop and acceleration - but at cruise and open road work they're OK.

PL
by PL
Mon Aug 16, 2021 8:48 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Yeah but 8% of K won't necessarily translate to 8% on your fuel trims though. I usually get my cruise mixtures about right using K/TIM, then see if I can get full boost fuelling correct using just fuel map values, then go back and check cruise mixtures and trim them out using injector latency if nee...
by PL
Mon Aug 16, 2021 6:37 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Increasing K, TIM and/or Injector Latency will increase fuel.

PL
by PL
Fri Aug 13, 2021 5:58 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

Sorry yes I meant a sniff LESS fuel as it's trimming in the negative direction.

PL
by PL
Thu Aug 12, 2021 9:21 pm
Forum: Type 3/4/5
Topic: Start tuning SR20DET
Replies: 48
Views: 290085

Re: Start tuning SR20DET

If it's running nicely I wouldn't touch it. I only ever look at the fuel trims under cruise conditions. They can be all over the place during transient operation. Looks like it could do with a sniff more fuel if LTFT is significantly negative. I'd be tempted to just trim it out by increasing your la...
by PL
Thu Jul 15, 2021 7:20 pm
Forum: Type 3/4/5
Topic: hi! from a newbie in canada. rb25det neo, in 240sx
Replies: 147
Views: 2292126

Re: hi! from a newbie in canada. rb25det neo, in 240sx

All good points there. I'd just go Walbro 255. Hard to go wrong for your HP goals. Just get a genuine one from a reputable seller. Lots of China fakes about. Yes the bigger rear housing would fix the problem but I fear it would add a ton of lag and you wouldn't like it. The 40mm TS comp-gate sounds ...
by PL
Mon Jul 12, 2021 7:28 pm
Forum: Type 3/4/5
Topic: hi! from a newbie in canada. rb25det neo, in 240sx
Replies: 147
Views: 2292126

Re: hi! from a newbie in canada. rb25det neo, in 240sx

Yeah some of them have different scales for fuel and IGN. Not sure why. It's certainly good to have a bit more resolution on the IGN map. Fuel doesn't really care if you run into the end column.

PL
by PL
Sun Jul 11, 2021 11:11 am
Forum: Type 3/4/5
Topic: hi! from a newbie in canada. rb25det neo, in 240sx
Replies: 147
Views: 2292126

Re: hi! from a newbie in canada. rb25det neo, in 240sx

Yeah you might just have to hold it down and see what boost does. Bear in mind that they'll tend to overboost more in low gears when boost comes up super fast. So if you have a nice safe piece of country road you could try rolling on in a higher gear. Another thing I like to do is have a "safet...