My Sr20det Refuses To Make Over 160kw

[llama_au]

Basically, I'm at a loss to explain it. So hopefully some tech-heads on here can lend me some advice.

The short relevant specs of the car related the Engine/Driveline are:

- JDM Avenir PNW10 SR20DET (2L Turbo) conversion from stock GA16DE (1.6L Naturally Aspirated), custom wiring harness, retaining Air-con.

- Avenir Auto ECU re-mapped by Dr Drift

- Nismo 740cc injectors

- Genuine Z32 Airflow Meter with Bosch plug

- HKS EVC 6 Boost Controller

- Two Aftermarket Auto Transmission Coolers

- 600x300x76 Hybrid Copy Front Mount Intercooler, custom Stainless Steel piping

- Go Fast Bits StealthFX BOV

- Custom Aluminium Pod Box with 3A Racing Pod Filter, Metal Intake Pipe

- GT28RS 'Disco Potato' .64 housing with modified actuator bracket and rod

- Pulsar RNN14 GTiR Exhaust Manifold

- Longer Manifold Studs

- Liverpool Exhaust 10mm Manifold Spacer Plate

- 3" full Stainless Steel mandrel bent Exhaust, Stainless Steel straight-though Muffler

- CES Split GTi-R Dump Pipe

- CES Metal Substrate Cat

- Pulse PHB650 Dry Cell Battery

- Pulsar N14 JDM SR18DE Auto Transmission with VLSD, rebuilt for turbo application completely from scratch;

Custom Valve Body

Custom Heavy Duty Clutch Packs and Hubs

Custom Heavy Duty Band and Drum 12mm wider than standard

Custom Torque Converter with Heavy Duty Lock Up Clutch and Roller Bearings

Custom machined Servo Assembly

SR18DE Sentra Shift Kit

The car is a 1998 Nissan Pulsar LX Sedan.

These are the most recent dyno sheets:

On 17PSI:

13PSI (stock actuator boost) VS 17PSI:

Note: Peak power is almost identical, it gets to a certain point (160fwkw) and plateaus off. No matter how much boost you run, it makes the same peak power. Torque and low-down power increase...but then it goes flat...

Wtf am I missing? The car has spark, fuel, boost. It's not running lean nor rich. Ignition timing has been backed off a smidge (2'.) The 13PSI reading was the untuned figure. The 17PSI reading is the tuned figure. It doesn't blow smoke, it doesn't misfire, it doesn't overheat, the Auto doesn't slip. What on earth could it be?

[The Mafia]

could be cams?

Thats kind of a wild guess.

[llama_au]

That's one thing I haven't touched, but planned to. I just wanted to rule out everything before I do that and find out it's possibly a waste of time Stock cams should have been good for somewhere over 200fwkw I would've thought.

[paulr33]

inlet restriction would be my guess

whats the inlet plenum and other stuff like?

sams tuned mored sr20's than you can poke a stick at - what did he say/suggest?

what gear was it dynoed in?

[boostin_r33]

yeah mayb cams u seem to have everything else!

[33gtst]

lotsa goodies in there...exactly how healthy is the engine? On a standard manifold? Is this possibly a bit of a restriction? Esp with a spacer plate?

I'd hate to think your auto trans is whats holding you back but there is def alot more loss through it though, no?

Wat did Sam say?

Edited June 16, 2008 by 33gtst

[llama_au]

Dyno'ed in 3rd gear - remember it's a 4spd Auto. 4th is just a cruising at over 100kmp/h gear, infact I can't use it under 100kmp/h.

Sam has no idea, I spent until midnight there one night. No-one has any idea why. My auto builder said it's not the auto, the car should make more power. You lose power through an auto but you don't not gain anything by winding up the boost. I can't gain a single kw.

Plenum is stock. My cooler and intake pipes are all mandrel bent. I'm not sure how the spacer plate could cause an issue as it's the exact shape of the manifold and there's no exhaust leaks, it's not restricting exhaust gases. The stock GTi-R manifold could be a restriction, however the car boosts well.

The health of the engine? I'm not sure. It's been in my car for roughly 20,000km and it's roughly 10 years old with no history. I bought it as a bare engine with '50,000km or less'. Judging my the condition under the rocker cover, it may not have been exactly correct. It was a bit sludgy but that's long since gone. I haven't had it compression tested, but I've never had reason to suspect that anything wrong with it. It's had probably 5 or more coolant flushes in 20,000km (or various reasons), probably 10 oil changes, multiple gaskets replaced, a brand new timing chain, tensioner and guides. That makes me think - could cam timing be out?

Edited June 16, 2008 by llama_au

[Rolls]

Done a leak down and compression test? Maybe something simple like a fuel blockage?

[llama_au]

No I haven't, but I'll add it to the list.

I'm really thinking it's timing now...I had my timing chain replaced a year ago - maybe it's out a tooth or two?

[The Mafia]

inlet restriction would be my guess

whats the inlet plenum and other stuff like?

sams tuned mored sr20's than you can poke a stick at - what did he say/suggest?

what gear was it dynoed in?

Done a leak down and compression test? Maybe something simple like a fuel blockage?

No I haven't, but I'll add it to the list.

I'm really thinking it's timing now...I had my timing chain replaced a year ago - maybe it's out a tooth or two?

Good old SAU for you.

The above are three really good suggestions you can try.

Stick with it mate, you'll find the problem.

[llama_au]

I hope so.

From Dr Drift:

Cam timing - Possibly

Skipped Tooth - Unlikely

Exhaust - Possibly

Intake System - Have seen a car once had a rag in cooler, so yeah, maybe, very similar symptoms...

Plenum / Cams - No Way, have seen 240+rwkw on standard plenum and cams

Ignition Timing - No way, plenty of timing mid range, can run more if need be no problems, but will det.

Auto - Like I said, unlikely as it wasn't slipping etc

I agree with what he's said, it's all pretty logical. I have a few things to look at, wish me luck.

[R31Nismoid]

Somethings

1. Drop exhaust just to be sure

2. Measure pressure before & after I/C to see if its causing a restriction

3. Re-Check the cam timing/belt is spot on

[llama_au]

SR runs a chain rather than a belt, but yep, definitely going to check that

[llama_au]

I've had a bit to think about over the last month. I wanted to rule out compression and timing first and foremost.

So, the good news. Compression is really good. 158, 160, 158, 158. In comparison my brothers 10,000km rebuild made 132, 132, 138, 132. Needless to say he's not particularly happy. It'd suggest that my engine does have the genuine km's it was sold to me as having (under 50,000km, it'd now have around 70,000km on it at maximum.) I wouldn't have guessed it the first time I saw it with the rocker cover off covered in thick sludgy oil. So I'm extremely happy my compression is factory spec.

The Auto is also fixed, but I'm now a bit out of pocket. I don't want to discuss all the details online but in a nutshell someone had bent the throttle cable and mechanisms going into the Auto when the turbo was fitted. As a result the Auto saw the car as being at 50% throttle...at idle!!! It was holding out the gear changes for the fact that at half throttle it thought the car was at wide open throttle. So now, it's back to driving, revving and changing gears like a normal car. I'm annoyed, but quite relieved.

Now timing was a bit of an interesting point. The timing light would suggest that at idle the car is barely running a couple of degree's of timing, it was hovering pretty close to the first marker (sometimes almost on 0'.) I was quite sure when I'd seen the consult readout it was closer to 12'.

The cause of my whack timing at idle was something so bloody simple it's actually pretty embarrassing. To compensate for a crappy idle the idle adjustment screw had been adjusted in the past and consequently the ECU saw that the car was idling too high and kept trying to retard the timing to 0' to compensate and bring it down. The consult was reading anywhere between 0' and 3' timing!!! It's now happily sitting on 15' which is factory.

It's also revealed where the screaming/whistling noise the car was making on boost was coming from, that tiny screw!

So when I have the time and money - now that everything mechanically is perfect, I'll go back for a re-tune. The only thing left to check out is whether there's an exhaust restriction.

[STATUS]

hmm the timing should have been checked before the tune... i remapped a std manual the other day and it made just shy of 190rwkw at 15psi so there is definately an issue, if you run out of ideas feel free to drop past, i have all the re-mapping gear for most nissans, evo's and unfortunatley subaru shitters

[STR8E180]

yeah mayb cams u seem to have everything else!

standard cams should still see at least 200rwkw

[DECIM8]

Flow restrictions.

[llama_au]

standard cams should still see at least 200rwkw

Front wheel

Trent - cheers for the offer, I'll be in contact if I can't get it sorted out

[202.3rwkw]

Mate - try a different set of tyres on the dyno.

[Dr_Drift]

Just to clarify the timing was spot on, the only reason it appeared to be incorrect was the ECU wasn't put into base timing lock mode when the other person tested it... Another workshop had wound the idle speed screw right out (high rpm) to account for some other problem (not sure why?)...

So basically as the ecu wasn't locked, and achieving the desired target idle rpm was outside the scope of the factory idle speed motor, the factory ecu retards idle timing in a last ditch attempt to lower the idle...

With the idle speed screw in the correct position the ecu no longer retarded the idle timing and was quite happy at 15 - exactly where it had been set prior to tune.

My vote is still flow restriction! Drop the exhaust and run dual map sensors, in plenum pressure & pre cooler pressure...

Have you checked the cam timing yet?