Help, car detonating on dyno

I had a little dyno done today to make sure everything was running safe. I will attach the dyno sheet later but there is nothing much it shoes. It is not running lean and power at the wheel is 337bhp@ 6000rpm which is what 380ish fly? However, this wasnt done at full throttle due to a detonation :flame Dev

Ive been talking to tDR and he advises me that these guys commonly see detonation because they use such a high resistance at constant WOT. Max boost pressure was 20.5psi.

The guy doing the dyno told me a bunch of stuff that I will try and remember but I need some education and advice about what to do now?

I probably need a restrictor ring as the quick fix to reduce the det. Now, is this det caused or just shown up by these rollers. What can i do now, is my car gonna blow up at constant WOT etc?

All advice very welcome.

Can't help with your question, but where did you go?

Just to add....the detonation is in the second turbo area up when producing 20lb of boooooooost.

Hey, went to AVA. Saw your car there. That steering wheel is looking good. Brian is reasuring me that the extremely high load they put on the car is the cause. Did you get something similar?

I got 300.8 at wheels - that was before decat/pump/plugs.

Did my car have the gearbox out when you saw it?!

Dont you have about a bilionty bhp now? Looked like it was untouched as far as I could see. I meant, did you get any detonation, I thought they mentioned you did.

I think it was about 1500bhp at 3bar boost.

Maybe that's why the clutch is fcuked

That's about 1.3 > 1.4 bar of boost isn't it?

Standard ceramics and standard IC?

I'd say first thing to look at is getting the boost down to a sensible level - did they check fuelling at all / how did you know you had detonation?

20.5psi = 1.413 bar

Yeah, 18psi is 1.2bar im sure. Thats the plan, to get a r/ring on there. They didnt check fueling, how would they? The guy at the engine bay end said he could hear the det pretty good.

EDITED - as I missed at first how high the boost was.

It might not be det. Though you will be running lean...

I'd get some proper spark plugs in it. Denso IK22's or IK24's. And I'd fit a restrictor plate post haste!

They should shove an O2 probe up the exhaust to test the fueling...if they don't have the kit (which is a bit lame IMO for a Dyno). I'd go somewhere else if they can't monitor your fuleing.

Yeah, 18psi is 1.2bar im sure. .

18/1.241 bar :-)

Thanks. Walbro went in by me a couple of days ago....THINK its ok. Plugs are only weeks old...really that bad?

The guy was pretty sure there was a massive det up top and scared me

I am gonna go to another place to double check and will ask about fuel testing. (These guys did CO2 monitoring).

I've edited my post now as I miss read the boost levels involved.

Your boost levels are waaaaaay to high for your mods, get a restrictor in there down to 1.1-1.2 tops

Amen, try running a colder plug, and some race gas if you want to run that amount of boost, which I think you wont.

How did they know it was detonating? what where you IAT temps like?

Did they use det cans? or was it plain pinging??

as said previous, det will depend on the following, Mixture ratio, combustion chamber temp, mixture presentation, and how hot the spark plug is, most like a domino affect can happen, once one of the symptons arrive others will follow.

what fuel did you use?

Ps, if it was massive DT up top, you would have had a hole in your pistons, and lost the motor, DET at high RPM and rip a motor apart, it causes massive in cylinder pressures, and puts a stupid amount of load on Rods, bearings, not to mention valves, esp exhaust ones if the spark retard is utilized too much.

Have have you been driving it since the pump, et? pretty hard?

EDIT - Buy a Wideband, I cannot emphasise this enough!

Have to agree, widband lambda will allow you to see just where your fueling needs changing (pref with data loging) Inovate LM-1 !

suprised that people have probs with the NGK platinum? its always the opposit with the Nissan s14 SR20DET! the Densos that are melting!

if you want to run that sort of boost, then some management is needed, emanage maybe, and perhaps larger injectors.

Im not trying to run this boost, its just happened as a result of the mods. I do intend to get it down with a restrictor ring.

They just "heard" the detonation, no equipment. The intercooler outlet temp was up to 50degrees at 6000rpm. I only use optimax in it.

Since fitting the pump I havent been driving it especially hard....the odd blast but nothing too stupid. Maybe a cause?

Should I deffo take out my NGK coppers and put platinum in?

Finally, someone will have to tell me what a wideband lambda is all about.

Cheers peeps.

Wideband lambda is in essence a highly accurate O2 sensor (like the std ECU uses to monitor fueling) its just able to read a wider range of AFR ratios, by using a wideband in conjunction with a piggyback or stand alone engine management, you will be able to ajust the fueling map to achieve the correct fueling throughout the rev/load range, hope this makes more sense.

Don't know about the plugs as i'm not to familiar with the Supras quirks yet!

very pretty car buy the way!

Cheers Ricky. Since I dont have a standalone and Im not likely to get one soon, I take it you cant get a wideband sensor on its own? I guess there wouldnt be any point as you couldnt adjust the AFR anyway. I guess its best to go to a place that measures AFR on the dyno too.

Can someone tell me at what level I can drive my car till I get the ring in? (Scared noob)

I would have thought that the first thing is to change the plugs, slightly colder and diferent type may help, and just don't rag it! RRs do tend to show up any det problems because they tend to run the car up in fourth gear, so it will show up det in the early part of the rev range due to the loading! (you wouldent normaly subject it to that sort of loading on the road)

woah woah STOP!

1st thing to note is the plugs are absolutely fine... they are NGK BKR7E (1 grade colder than stock) which incidentally are not platinum (these aren't used in modded cars - manufacturers only use them for extended service intervals). Denso's are just a waste of money IMO - I've had no probs with NGK coppers on an engine putting out almost twice what it should do.

2nd thing to note is that AVA rollers are the fully braked type - IE to take a power reading they apply such a braking force on the rollers that the engine is under the most extreme load - the car sits there at wide open throttle and the wheels not spinning. This has two connotations - the first being the car produces more boost than it would on the road in the same way as driving up a very steep hill at WOT with 5 m8s in the car and a boot full of luggage would produce more boost than normal - more engine load = more boost. The 2nd being this abnormal engine loading and extra boost results in det that you wouldn't see under normal driving on the road. Many of the Scots on sxoc have been to AVA and the result is always the same - car runs 15psi on the road... goes on their rollers and produces 17 or 18psi, dets at the top end and AVA say lower boost... gets lowered to 15 or below on rollers... car goes back on the road and produces 13psi or less!

Hamish - I wouldn't worry too much m8, just keep an eye on the boost gauge when you mash the throttle and make sure you stick around 17psi or 18psi tops, back off if it tries to go above. Get yourself along to Dastek where they have a decent normal type rolling road that keeps the wheels spinning during a power run and also they have a wideband to check your fuelling with. Gerry there worked for Toyota Team Europe on the rally cars and knows his stuff.... he will advise you on fuelling / det throughout the rev range and hopefully set your mind at ease.

You don't need to buy a wideband lambda, you don't need new plugs - they're only a few hundred miles old lol.

HTH,

Bri.

.......and now the nightmares will go away lol

I will deffo get along to another rolling road, reasses the situation and decide what restrictor ring to get.

i got the same thing at AVA, det at the top end. that was about 6 months ago. and they did check the fueling with a probe in the exhaust, i remember cause they tied it to an axle stand when the gas blew it over