The pursuit of decent power in my auto ?

[paulzy123]

Hi everyone,

Firstly, what a great forum this is, it’s the fountain of knowledge for everything skyline related, it’s taken years to build this up and is the best forum for skylines out there, it has helped me loads, thank you.

So I’ve been frequenting this forum on off for a while now, trying to get the information I need to achieve decent figures in my auto. After sorting the gearbox (401) with an additional bigger cooler (28 row mocal) and an MV auto’s stage 2 shift kit I then fitted a hybrid turbo, 440cc injectors and Emanage ultimate, bigger inter cooler and free flowing exhaust and exhaust manifold, 1.1mm steel head gasket and ARP head bolts. New water and oil pump.

Off it went to be mapped, it returned with a nice 348 at the fly wheel figure at .85 bar. I think this equates to around 200rwkw depending in what fudge factor is being used? I could well be wrong, it wouldn’t be the first time...

I’ve read lots of posts on here probably the automatic performance thread back to front at least 5 times but I still forget stuff.

The car went off to be mapped again last week as I really want that 400 at the fly figure which I’m guessing is around the 250-260rwkw mark.

After they found and fixed my very leaky rubber inlet manifold gasket they got her on the dyno.

I got a message asking what I have changed on the car since it was last mapped as it’s only making 300 at the fly now and turning the boost up makes no difference. My mapper said it is like an exhaust restriction and asked if I have a cat but I haven’t, it straight through.

The car has barely done 1k miles since it was mapped at this time last year so I’m a little stumped.?

It has a standard bov, and a gizmo boost controller, they have leak tested it and there are no boost leaks. I’m also told the injectors are not maxing out and that turning the boost up isn’t making any difference. I’ve asked for him to look up the exhaust tomorrow to see if anything is up there that shouldn’t be, failing that???? It’s a rebuilt hybrid that went in when it was mapped last year. 

I only ever drive it gently all the way to the drag strip and then home again, maybe I’ll take it out and cruise around once in a blue moon but I never go flat out other than half a dozen times at the strip. 

The air filter has been checked and is fine also.

Some of you guys will know this one even though what I’ve just written in my mind doesn’t compute.

Any help or advice on this would be greatly appreciated as I’m not going manual even though I get a fair bit of flack for being auto.

Thanks in advance

Paul

Edited December 11, 2018 by paulzy123
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[KiwiRS4T]

Where are you getting these "at the fly" numbers? Do you take the engine out and put it on a bench dyno?

What are the afrs doing... is it running out of fuel? Find a way to pressure test before and after the intercooler.  What kind of turbo is it? Who built it? What is it supposed to be capable of? What kind of "free flowing" exhaust manifold do you have? What diameter is your exhaust (and does it narrow down to a 2 1/2 in muffler?

Driving it gently isn't helping - give it heaps (when the road allows and it is at operating temps).

Does your tuner have a good reputation (with the RB brigade or generally)? Really would expect some answers from him (or her).

[paulzy123]

Hi, 

The at the fly wheel figures are calculated based on a wheel figure that the dyno measures then is worked back back using a figure to compensate for transmission losses. You don’t really see many dyno graphs showing wheel horsepower over here which is annoying as crank horse power is calculated, having a transmission that’s auto also increases the losses to the wheels over a manual so it’s even more out.

the afr’s are ok, I’m not there when it’s being looked at and dyno’d but when it was set up a year ago apparently the afr’s were “super safe” I could post a sheet showing the at the fly wheel and afr’s from the mapping that was done a year ago I’d that helps?

The guy pressure tests both before and after the Intercooler.

It’s a hybrid turbo built by a very well known company in England.

The guy who maps it is a well known guy on the Nissan sr 20 and rb scene and has been established  over 15 years with a good rep, expensive but good.

its a 3” straight through system, the manifold is a 3mm steam pipe low mount, weighs a ton cost £400.

Today I got a message saying that it won’t make any more power with more boost or timing and made 290hp (fly wheel) @.95 bar.

I’m guessing either turbo or compression. It did have s boost leak for a while, could this have made the turbo over work to create the target boost to the point it’s damaged the turbo? 

[KiwiRS4T]

The AFRs might have been ok a year ago but your fuel pump may be failing or filters clogging. This should show as AFRs leaning out. The pressure drop across the intercooler could have increased as well. 1 bar seems very conservative - does your tuner have any other ideas about what might be holding you back? If the tuner suspects an exhaust restriction usual plan would be to do a run with the exhaust disconnected and see if that helps.

[paulzy123]

Hi, 

So I paid up today and got my keys back, collecting tomorrow, afr’s are the same as last December as is the way it builds boost.

He said he is stumped ...and the thing is I know the guy isn’t a bulls**ter. Also said compression “feels good” hmmmm ..

I do really respect the guy and he is probably one of the best (if not the best) mappers for rb’s in the uk.

I want to protect his anonymity because he is good and people always judge but I’m a little lost with it. I’ve compared graphs from last year and now, the car has done 900 miles approx since last December but I got the sheets back and they are showing 290 hp at the fly, last year showed 348 hp.

I have a walbro 255lph pump so should be fine and not running out of puff..

I really want to go rb25/30 but Rb 30’s over here are like hens teeth..no.. hens wisdom teeth..

Im going to do a compression test and see where things are on that front.

Pressure drop across the Intercooler? It’s a side mount (big Toyota supra one as don’t want to cut the bumper around and will support 450 apparently) but old, maybe it could have degraded since last year but  I doubt it...

So, I pick it up tomorrow ... 

Thanks for getting back to me.

Anything else it could be? 

Cheers

Paul

 

 

[KiwiRS4T]

If you are still on a side mount that will be holding you back. Don't know how you got the big number last time but you can get a fmic that doesn't require surgery or you could get a Blitz return flow front mount that uses the existing holes for the piping.

https://www.youtube.com/watch?v=x3cUGUWvP1g

but yes do a compression test and report back!!

[paulzy123]

Will do!!!

A side mount is where I want to stay ( I spent nearly a year reading up on air flow..) , I read up that a standard Toyota supra would flow at least 400... they have just released a side mount that will meet 500 so I wil get one if things are hindered ..

It’s going to have a compression test I the morning .

Cheers Bob

speak shortly ?

[GTSBoy]

Nope.  The Supra coolers are junk*.  You do not want them.

*They're better junk than the little Nissan ones, but still junk.  They are also quite poor from a thermal efficiency point of view.  Short tubes.

[KiwiRS4T]

10 hours ago, paulzy123 said:

 

A side mount is where I want to stay ( I spent nearly a year reading up on air flow..) , I read up that a standard Toyota supra would flow at least 400.

 

 

?

5 minutes on the dyno is worth a year or reading. I tried a succession of increasingly large sidemounts but had to give up and get a front mount. Get one of those digital thermometer guns and check the before and after temps on your intercooler pipes after doing three of four power runs (can do it on the road if necessary) - it won't take long before heat soak sets in.

[paulzy123]

Ok cool, well that’s something I need to get sorted and will do but will go the blitz return flow route as don’t want to cut anything ? Right now I’ve got bigger problems as I just picked the car up and it’s locked in third, I told him about the brown plug behind the headlight that if you disconnect it the car locks into third so he could dyno it but its still in third now ?

Will have a good look at it tomorrow as it pouring with rain, dark and about 2 degrees outside - typical English weather.....

Thanks for the responses guys ?

Think I'm going to get it unlocked from third first thing. I’m just hoping the brown plug is discconnected as if it’s not then it’s locked in third permanent ?

 

[paulzy123]

So the brown plug was unplugged still as suspected, I got it plugged back in and it sorted it...

Couldn’t do the tests on the car in the end as my mates laptop was playing up, looking like next weekend now.

[paulzy123]

The car was mapped with the brown plug behind the headlight removed to lock it into third. Does this also lock the timing does anybody know? I’ve had conflicting reports.

Just got home from work so will take the car out with the brown plug back in and see how it performs as although cold it’s dry.

Scared what I might find Saturday with a compression test if I’m honest ...

[paulzy123]

Well the car drives fine just low on power,

Did a compression test

1-167psi

2-165psi

3-153psi

4-153psi

5-162psi

6-167psi

Taking into account I have a 1.1mm head gasket then the compression test looks ok to me. So the quest continues to find where my 58hp has gone....

[KiwiRS4T]

Do some testing. Do the before and after temps on the intercooler. Do an 80 - 120km time and then (find a quiet road) drop the exhaust (hold it up with wire) and repeat the test.

The middle compressions are a bit low for my liking. Is there any tendency to overheat?

Still got stock BOV? rubber hose in good condition?

What happens when the boost is turned up? EGTs get too high? Or just no power? Maybe pull the turbo off and inspect it.

[paulzy123]

Will crack on with some testing ?

Never overheats to my knowledge obviously going by the stock temphreture gauge though..

Still on a standard recirc but I have an genuine adjustable greddy one that I can fit if it’s that. All hoses from what I can tell are in good nic ....

I’m not there when it’s being mapped ever but last reports were that turning the boost up and advancing the ignition made no difference.

I’m fairly confident the brown plug locked the timing at 15 degrees but will need to confirm this...

Cheers

 

[GTSBoy]

9 hours ago, paulzy123 said:

Never overheats to my knowledge obviously going by the stock temphreture gauge though..

Yeah, nah.  Coolant temp is not an indicator of EGTs.  You need a pyro or 6 installed to see that.

[paulzy123]

Doh!! Yup you are absolutely right, I often see egt gauges for sale and think will their  function ever really be needed as if your engine is good then it’s good but in this situation it would be a bloody useful reference...

I just don’t want to have a multitude of gauges as I personally think it can get a bit much...

[GTSBoy]

That's why I did not put any aftermarket gauges into my car that were already on the dash.  Well, except the boost gauge, and I probably should swap that out for something else.  EGT, Oil T, & boost, in the centre console.  3x 52mm panel.  Works and does not crowd the place out.

[paulzy123]

I want a boost gauge as that would have shown my inlet mani gasket had gone a while back, I also want to watch gearbox oil temp so thinking of getting both as  greddy gauges in a pillar pod.

I have another sensor in front of the throttle body wired back to a digital meter that’s sat snug in the front of the ash tray which shows inlet temps off boost in summer sits around 20 -25 degrees and at wot it can shoot up but never on the loud pedal long enough for it to show above 40/45 really..

I'm thinking afr would be a good one also but never really needed until this type of thing popped up or if I was trying to map my Emanage myself...

Happy Christmas everyone by the way.

?

[GTSBoy]

2 hours ago, paulzy123 said:

a boost gauge as that would have shown my inlet mani gasket had gone a while back

No it wouldn't.  Gap would have to be MASSIVE to let that much air out.