Bad results on the Dyno

[MKIV]

Oops, didn't mean ARP rod bolts (they were using stock rod bolts as couldn't find an aftermarket alternative for stock RB20DET conrods), meant ARP head bolts, etc.

RB25DET is limited by compression it runs. As far as I know most stick to 20psi max with say a GT3076R turbo or equivalent turbo (TD06, etc). At I think was 17psi?, GT3076R with correct exhaust housing, aggressive ECU tune, etc produces around 402whp.

Froom what I understand, higher pressure radiator cap is used on thicker radiator (Nismo or similar) due to pressure drops if use stock radiator and usually need upgraded headgasket, upgraded water plugs (to handle higher pressure) to suit. Also higher pressure radiator cap is used on radiator with header tank setup (header tank separates air bubbles that are created by waterpump from coolant, as the air bubbles can clog passages in radiator, etc and make engine overheat when at high revs all the time). N1 waterpump due to blade design reduces the creation of bubbles at high rpm, but is not good if engine is idling alot in stop and start traffic (stock waterpump is better).

On stock radiator it's just going to overpressurise the stock cooling system and waterpump leaks, headgasket or water plugs could blow, top tank on radiator could blow gasket and leak, etc. Basically I was warned not to do it on stock cooling system.

So bottom line, avoid high pressure rad caps on stock rad, and try not to idle too much with the N1 water pump.

I haven't heard any bad things yet about the N1 water pump so I'm hoping it does it's job. As far as the compression I'll be running, should be slightly lower with the 1.2mm metal head gasket. Pretty excited to see what it'll make next year.

[Skym]

Replacing radiator cap and thermostat is a good idea. I have done both on my car. On my car stock thermostat nearly stuck closed and that would have resulted in overpressurising cooling system, blowing headgasket, etc. Caught it in time before major damage was done. When stock thermostat failed, my cars engine hit around 95 degrees (tested thermostat after removing it) before thermostat opened and found out water level dropped in radiator.

I was told with thermostat, you need to monitor coolant temps (water temp gauge) while driving and change to lower temp thermostat if needed (usually when car is used on racetrack). Nismo low temp thermostat is fitted when coolant temps spike to dangerous levels (90-110) while driving hard (racetrack). At idle with low temp thermostat it normally sits at around 62.5? degrees or just below halfway on stock coolant temp gauge and should spike into 80-90 degree area. Stock thermostat is around 78.5? degrees when it starts to open (I think is fully open around 90 degrees) and should be around 78-80 at idle when stock (my car sits at around 82 degrees when at idle and was 78-80 degrees when stock) and around 80-90 degree area when driving.

Learnt about N1 pump problem from a GTR owner who had overheating problem while in stop and start traffic and found out N1 waterpump was the cause.

Also Nismo use stock waterpump (genuine) on S-tune (Street tune) engines -

http://www.nismo.co.jp/omori_factory/original_menu/engine_m/s2/index.html

Also noticed on R-tune engine they use N1 waterpump (they call it "N1 specification" or something like that), but is not mentioned in this revised list for R2 (from what I can remember, was on list for R1) -

http://www.nismo.co.jp/omori_factory/original_menu/engine_m/r2/index.html

[Supraclean]

Ouch 11.6 afr is a bit rich, okay if your strip only but for a daily driver you are going to just wash the rings out of your engine. Stock motor on moderate boost it is fine to run 12.5 afr and peak at 12 , if your racing then by all means bump it up a bit to 11.5 or lower but not for daily driving. We have 4 imported cars we have been running now for years now either daily drivers or race and have no problems as of yet. Good dyno results and good exhaust temps

11.6 rich? think you mean Lean not.

[Skym]

10.7:1 like factory run at peak hp for RB20DET is rich.

[BongRips]

I may be mistaken, but isn't 11.7:1 optimal at peak hp for forced induction cars?

[Skym]

It's safe when taking into account inlet temps, cylinder temps, etc engine is going to face like on a racetrack, etc or basically when driven hard. Like Nismocan said, exhaust temp is a way to monitor how hot engine is running in cylinders. But I'm not sure about washing the bores of oil, as from what I understand it has to be into low 10's to do that. Factory running it rich is close but those stock engines last 200,000km+ without problems.

A street driven stock RB20DET I know of when pushed to 12.4:1 at peak hp and combined with advanced ignition timing, 16psi from HKS25/30 to get max hp from engine was a engine that was going to blow up and did when thrashed. Custom intercooler not being good enough with cooling (high cylinder temps) and stock ECU that can't adjust to higher inlet temps, lean A/F ratio (high cylinder temps), etc played role in this failure due to knock. Switch to GTR FMIC helped to solve the inlet temp problem, even when running same A/F ratio. That's running in fairly hot environment (Australia).

That's why I would run engine richer as some intercoolers are not good at cooling (and some with flow), especially stock intercoolers like found on RB20DET, RB25DET that can heat soak. But Nismocan was saying moderate boost levels, which I don't know what boost level it is. I've seen temp probe results of running 7psi with FMIC on RB25DET and inlet temps are quite high when switching from just 16-21 degrees with ambient temp.

[BongRips]

What is a good afr for a target then? 14.7 at idle, right? But what do I want for peak hp and how gradually or quickly should I change to that on my mapping?

[Skym]

Best to talk to a tuner, or watch a tuner tune your car and learn that way, as it's something that needs to be done on a dyno where can control what cell on fuel map it lands on accurately.

To give you an idea, look at post no 233 in this link -

http://www.skylinesaustralia.com/forums/topic/103095-rb20-turbo-upgrade-all-dyno-results/page__st__220__p__4449438#entry4449438

It has A/F vs boost graph, which shows you what it should do when coming onto boost (WOT or Wide Open Throttle run). It's a tad lean down low at 15's? off boost which caused knocking problems, so ignore that part. On WOT run it can run across the fuel map from one side to the other (low load at idle to high load when under boost).

Can see on tuners laptop when tuning RB20DET that it's running across the map on WOT run -

http://www.youtube.com/watch?v=mSkFzn4rZ1U

But be aware some maps in ECU tuning software are setup differently with direction of scaling, so high load, high rpm could be in the bottom right (like shown in link above) instead of top right like with stock ECU tuning software.

Or do these ECU tuning courses and learn to tune engine yourself -

http://www.efi101.com/

Also be aware that cheaper widebands can be off by 0.6:1. More expensive widebands that tuners use can be off by 0.1:1, so are more accurate.

[Zacho]

There is no "golden AFR" for all setups, you don't run x AFR at 1 bar and x at 1.5 bar. I personally like to run a little rich @ peak torque where bad things can happen and quickly taper to my desired ratio.

Ignition timing has a FAR FAR greater effect on power output/spool/heat produced.

Watch this video. While it is an NA car, it is great information. Take it with a grain of salt though.

http://www.youtube.com/watch?v=Zzn3-ygH-v8

If you guys want to tune your own cars I highly recommend getting on amazon and buying a book or two.

[MKIV]

There is no "golden AFR" for all setups, you don't run x AFR at 1 bar and x at 1.5 bar. I personally like to run a little rich @ peak torque where bad things can happen and quickly taper to my desired ratio.

Ignition timing has a FAR FAR greater effect on power output/spool/heat produced.

Watch this video. While it is an NA car, it is great information. Take it with a grain of salt though.

http://www.youtube.com/watch?v=Zzn3-ygH-v8

If you guys want to tune your own cars I highly recommend getting on amazon and buying a book or two.

Thanks for the link,

Have you tuned a car before?

[BongRips]

When I was talking with my tuner before I stored my car he said the Haltech software is great and simple to use and I could figure it out and tune it myself. I plan on buying three books off Amazon over the winter and reading up on the subject heavily and then try it slowly in the spring

[MKIV]

Haltech for the win! Did you get it from Pur?

[Skym]

A/F ratio is different between NA and turbo and changes based on fuel your running (E85, pump gas, etc).

Also need to know the tuning procedure and that can be learned via watching tuner set your car up for dyno, tune maps, etc or by doing the above course or talk to a tuner and ask what is the correct procedure.

I think those books don't cover how to tune a ECU, more this sensor does that, etc. Would be interested to know if you do find a good book to learn from, as I couldn't find one that does teach ECU tuning.

[BongRips]

I found two by Greg Banish that have got nothing but great reviews, so I got those and another one that got a good review too and was recommended with the other two

And yea I definitely got my ECU from PUR, they were SUCH an amazing deal at the time.

[BongRips]

Here's links for the three I ordered.

Engine Management: Advanced Tuning

http://www.amazon.ca/Engine-Management-Advanced-Greg-Banish/dp/1932494421/ref=pd_cp_b_4

Designing and Tuning High Performance Fuel Injection Systems

http://www.amazon.ca/High-Perf-Fuel-Injection-Systems-Banish/dp/1932494901/ref=pd_bxgy_b_img_b

How to Tune and Modify Engine Management Systems

http://www.amazon.ca/Tune-Modify-Engine-Management-Systems/dp/0760315825/ref=pd_bxgy_b_img_c

I would love to take the EFI 101 courses, most likely the ACP program as it includes 20 hours using a dyno or something like that. But at $5000, I don't have enough cash saved up to take time off work, and then spend that much on the course and the money to get down there and stay there for the course. As soon as I could afford it though, I'm definitely planning on going to take it to get certified.