The Next Step

[turbotom]

I'm intrigued by the pipe blowing off phenomena....

Is it blowing off before or after the IC ?

What boost are you getting at the inlet manifold?

The standard IC and plumbing isn't very efficient at elevated boost levels, and I'm wondering that if you are getting around 15 psi at the inlet manifold (for your 302 rwkw pk), then the pressure peak at the turbo would be much higher.

Take into consideration the pressure pulse that also occurs on throttle shut off immediately after a max boost power run, and any restriction of gas flow through the blow off valve, and you might be seeing quite a destructive high boost spike in the turbo to IC piping, and hence the pipe blowing off.

Probably better the pipe blow off than the turbo spit its blade.

there'd also be a lot of load placed on the exhaust turbine too, with a standard waste gate trying to cope with the additional boost output....

Do you have a fast response boost gauge installed? What does it peak at?

Have you had anyone measure the peak pressure on the turbo to IC pipework?

just some food for thought to consider......

Maybe your tuner can advise you .....

tom

[turbotom]

We've covered all of this many times before. Trough's tune wasn't finished so he didn't want to post a dyno graph and drag racing isn't for everyone.

Please guys, can we just stick to the topic...

Have I missed something.....

What do you mean his tune wasn't finished?

Why the heck would he be driving it hard if the tune hasn't been completed properly?

that's just

[Eugene]

WOW,

Poor old Lolly asked for some advice on where to head to next and copped a bashing, if lolly is happy that his dyno run is correct, then so be it, he didnt start this thread to debate the fact, what he wanted was some usefull input from people who have taken the next step in power level to see what they think should be next.

The first two things I would check is peak boost presure, to try and find out why your coolet pipe is coming of, if its coming of the supply from the turbo to the cooler, then I would say you may have a higher than expected restiction in the cooler, place a boost gauge BEFORE the cooler and compare it to your manifold presure, you may be suprised.

Have a long hard look at your AFR's, you have said they were safe, but after a recent dyno day in Newcastle, there were 4 cars that thought they were safe and at around 295-305rwkw were in the high 12's to mid 13's AFR, to me this isnt safe, at this power level I think you would want as close to 12:1 AFR as you can get, maybe even a little richer 11.9:1, it wont cost you any power but will make you engine so much happier.

For a Race fuel tune which is going to be used at the drags, your on the gas for 12-13 sec, an AFR of 12.6-1.8:1 will be fine, but I would not use it all the time, a crap load of fuel, a few people in the car and you will have issues.

Check your boost at maximum load wide open throttle, if you can hold over 14psi, I would say your waste gate acctuator is OK, if it is less, have a look at it too.

Check by disconcting the soliniod to acctuator line and blocking it, this will give you the release pressure of the acctuator, YOU WONT HAVE BOOST CONTROL AT ALL, be careful when you wind it up you dont have a big boost spike, ease into it until about 3500rpm and then floor it, look at what boost you can hold till redline, this is you acctuator high load peak boost pressure, and it is all you will get up top, ever, to increase it a higher pressure acctuator, or better flowing exhaust, intake setup will be required.

Fuel pump: I didnt see a mention of it, if your power level is correct, then you are on the limit of the fuel pump, for the cost of a Walbro GSS341 (about $170 off ebay) you will have sold fuel supply, very important when on the edge. Sedan are an easy fit, just do it.

1: check peak boost before and after the cooler, this will indicate boost drop over cooler.

2: Look long and hard at your AFR's, make sure they are SPOT-ON.

3: check your acctuators peak boost capacity.

4: replace the fuel pump, it is cheap insurance.

Keep us posted.

[igsta]

WOW,

Have a long hard look at your AFR's, you have said they were safe, but after a recent dyno day in Newcastle, there were 4 cars that thought they were safe and at around 295-305rwkw were in the high 12's to mid 13's AFR, to me this isnt safe, at this power level I think you would want as close to 12:1 AFR as you can get, maybe even a little richer 11.9:1, it wont cost you any power but will make you engine so much happier.

Im sure Simon form Nizpro knows what he is doing when he trys to tune his cars to AFRs of 12.6 to 12.9. He reckons this is the optimum ratio for power. Any richer and you start to loose power. The engine is happy and clean. My car makes the best power when its AFRs are low 13s then mid 12s up top. I guess alot of tuners make the mixtures richer to cover their backsides.

Edited 01/02/06 05:53 AM by AdamXR6T

[Eugene]

WOW,

Have a long hard look at your AFR's, you have said they were safe, but after a recent dyno day in Newcastle, there were 4 cars that thought they were safe and at around 295-305rwkw were in the high 12's to mid 13's AFR, to me this isnt safe, at this power level I think you would want as close to 12:1 AFR as you can get, maybe even a little richer 11.9:1, it wont cost you any power but will make you engine so much happier.

Im sure Simon form Nizpro knows what he is doing when he trys to tune his cars to AFRs of 12.6 to 12.9. He reckons this is the optimum ratio for power. Any richer and you start to loose power. The engine is happy and clean. My car makes the best power when its AFRs are low 13s then mid 12s up top. I guess alot of tuners make the mixtures richer to cover their backsides.

Low 13's then mid 12's up top, exactly, not mid to high 13's all the way through

I was not aware of who had tuned his car since wog did it, last I heard his tune "wasnt Finished", hense the suggestion to look closley at his AFR, it wasnt a slag at any tuner, just a recomendation.

As you said and I did too , 12.6-12.8:1 afr's are cool for a race / high octane map, but add some variables, like crap fuel, high load etc, then a 12.8: afr wont be much fun, drags, cool, everyday I think it is too lean to allow for variables.

After many hours on the dyno, with both mine and another car, bringing the AFR from 13.1 dont to 12.1 gained power, no other changes were made, less boost was used, and an increase of 8 rwkw was found, I know each car is different, but I have seen it on three XR6 T so far, once you drop below 11.9:1 AFR then you will loose power, hence my recomnedation for a setting as close to 12:1 AFR as posible to ensure it is safe for all conditions.

"Low 13's then mid 12's up top", I see cars with AFR's that start as high as 14.5 early on in the run, then quickly go down to mid 12's, it is when they dont go down to mid 12's and stay around 13's you have problems.

If a car is only running 8psi boost and 240rwkw, then mid 12's afr will be fine, there is a lot less load on that engine than one at 300rwkw and 15-16psi boost.

Robs car at a the recent dyno day had a High end of 13.5:1 AFR, (he thought it was a safe mid 12), we dropped it 12.4, and picked up 3rwkw, car is happier, boost is lower, again wht I recomended CHECKING His AFR to ensure it is what he thinks it is, any small change, air fliter, fuel filter etc will change the afr's.

Maybe I dont know what I am saying, but as quoted, lolly like to drive his car hard, making sure his engine is safe should be his No1 priority.

Edited 01/02/06 05:54 AM by AdamXR6T

[igsta]

Good reply Eugene. I hear what you are saying.

[BAturb]

well ive achieved what I think is a pretty damn good result considering what ive spent but im after the next level, with my current mods on octane boosted fuel I achieved 302.4rwkw

<{POST_SNAPBACK}>

now that the tune is finished and you are pleased with the result how about posting your dyno sheet with the boost and AFR's? simple request Im sure eveyone is curious

[jetute]

and his back at it

[BAturb]

just a simple request, he has said before he wont post until the tune was finished, as far as everyone can see the tune is finished,where is the dyno sheets?

[jetute]

just s request that is getting extremely boring and very repetitive.... why continue??