Some horses are missing

[Jimmy_GTT]

I have the feeling that somehow some hps are missing from my car. It has been rebuild 3 years ago. Got a KTR power cam in it (without vernier) ported head, T2/T25 hybrid, FMIC, oil cooler, 2.5 exhaust.
First it was built up with stb. ignition (RE209) and carb. AFR installed fueling is OK. Than I've installed megasquirt first only for ignition with the map received from Scoff. That time I've raised the boost to around 18-19psi. But still on carb. Than I've measured the performance (with an AP22 G-force meter) and it showed 135hp on wheel. I've also run some 1/4 miles with a trap speed 155-156kmh. Which also confirms that the car is around 160hp crank.
During winther I've installed EFI. And now on the same boost I've 142hp @wheel.
Yesterday I've done a compression test. All 4 results are between 10.2-10.7bar. (150-158psi) Seems to be good. Spark plugs are also looking good.

But as I've seen some RR results here on the same boost cars are around 185-195hp @crank. And I've also measured my friends totally std. GTT (maybe 1-2 psi more than original boost) with the AP22 and it showed 115-117hp @wheel. And that car is full standard. I've rebuilt its engine last year.

What is your opinion? What could be wrong?

[Sparkie]

where are you measuring boost from?

what is your head depth?

it also looks like you are getting you wheel and crank figures mixed up.

200 bhp at the wheels is about 230 at the crank.

[Jimmy_GTT]

where are you measuring boost from?

what is your head depth?

it also looks like you are getting you wheel and crank figures mixed up.

200 bhp at the wheels is about 230 at the crank.

Where did I mixed them up?
As I know it is std. 73.5mm.
I'm measuring boost after the throttle.

[Fordy]

can you add in anymore ignition timing on boost without hitting det or mbt?

[Jimmy_GTT]

can you add in anymore ignition timing on boost without hitting det or mbt?

Currently I'm using Scoff's map. I haven't modified it.
Probably I can add some more advance. In which range? How much?
If anyone has an ignition map it would be a great help!
(I know, I know a map which is working for one could det in another engine. I mean just as a reference.)

[Fordy]

make some det cans, dial the fueling into 11.5's on boost
then add a degree of timing to the on boost load sites in the map, having not used a megasquirt i can't be too in depth

but it sounds like you need more timing, how much more is all up to how well your engine copes and how soon it reachs mbt or the det threshold

if your not confident then take it to be properly tuned on the dyno or road by someone with a good reputation

[Jimmy_GTT]

make some det cans, dial the fueling into 11.5's on boost
then add a degree of timing to the on boost load sites in the map, having not used a megasquirt i can't be too in depth

but it sounds like you need more timing, how much more is all up to how well your engine copes and how soon it reachs mbt or the det threshold

if your not confident then take it to be properly tuned on the dyno or road by someone with a good reputation

Thanks mate.
What is mbt? Where the peak pressure is?

[Tony Walker]

perhaps cam timing not correctly set? the original ignition map(renix) with those compression results at 19psi i would of thought 160easily?

[Tony Walker]

mbt, minimum spark advance for best torque.

[Jimmy_GTT]

mbt, minimum spark advance for best torque.

Thanks!

Yes, I'd also expect around 160hp @wheel

[Jimmy_GTT]

make some det cans, dial the fueling into 11.5's on boost
then add a degree of timing to the on boost load sites in the map, having not used a megasquirt i can't be too in depth

but it sounds like you need more timing, how much more is all up to how well your engine copes and how soon it reachs mbt or the det threshold

if your not confident then take it to be properly tuned on the dyno or road by someone with a good reputation

11.5? Isn't that too reach? I've set it to 12-12.5

[Fordy]

considering how sensitive these engines can be, running at 11.5-11.8afr will give a nice safety factor without loosing any/much power at all. Plus when you start adding in timing if the engine is making more power it should effectively lean off slightly with more timing

any chance you can post up a copy of the timing map?

[Andrew Cooke]

which is the KTR power cam, is it the piper 270? They advertised it as the KTEC 260. It's a mild cam, but probably right for your turbo. I'd check the cam timing as Piper can be a bit variable.

also, what are you using for a cranktrigger, is it set right?

[Jimmy_GTT]

which is the KTR power cam, is it the piper 270? They advertised it as the KTEC 260. It's a mild cam, but probably right for your turbo. I'd check the cam timing as Piper can be a bit variable.

also, what are you using for a cranktrigger, is it set right?

Yes, as I know it is the KTEC 260. And since installed the car pulls harder around 5000rpm than before.

My cranktrigger is from Scoff. And I've double checked it last week with a strob and if I set 8deg for idle in megasquirt is it exactly 8 degrees on the flywheel - gearbox sign.

[Jimmy_GTT]

considering how sensitive these engines can be, running at 11.5-11.8afr will give a nice safety factor without loosing any/much power at all. Plus when you start adding in timing if the engine is making more power it should effectively lean off slightly with more timing

any chance you can post up a copy of the timing map?

Yes I'll in the evening.

What I've observed earlier if the AFR goes around 10.5 than the car is much weaker.

[Jimmy_GTT]

Could it be that the compressor side of the T2/T25 hybrid makes too much backpressure?
With the EFI the engine could breath easier. I have a 2.5 exhaust with a Big Jim downpipe, but maybe the compressor side of the turbo is too restrictive.

[Andrew Cooke]

you're getting the boost, so the compressor can't be too bad.

[Jimmy_GTT]

considering how sensitive these engines can be, running at 11.5-11.8afr will give a nice safety factor without loosing any/much power at all. Plus when you start adding in timing if the engine is making more power it should effectively lean off slightly with more timing

any chance you can post up a copy of the timing map?

Here is my ignition map:

[Jimmy_GTT]

And a part of my log file. Changing from 2nd to 3rd, than 4th. AFR is 11.6 at the line.

[Scoff]

At 1.4 bar you'll have a couple degrees less timing than the RE209. The base map I distributed was a bit on the conservative side so as fordy says you might be able to make a little more power with a couple more degrees. But, don't do this without good knock monitoring.

What is your compression ratio ? Too low won't help. If it's lower than standard then you'll almost certainly do better with a bit more timing, or better still if you brought the ratio back up.

[Jimmy_GTT]

At 1.4 bar you'll have a couple degrees less timing than the RE209. The base map I distributed was a bit on the conservative side so as fordy says you might be able to make a little more power with a couple more degrees. But, don't do this without good knock monitoring.

What is your compression ratio ? Too low won't help. If it's lower than standard then you'll almost certainly do better with a bit more timing, or better still if you brought the ratio back up.

I've just posted my ignition map.
I'm planning to make a det cam during the week before making any change in the ignition table.
And maybe I'll also try E85 later. But than I have to remap fuel.

As I know CR is std. The compression test results are also prove it. (around 150psi)


But I think a std. GTT engine would det @1.4bar with the std. RE209, wouldn't it?

[Scoff]

I've just posted my ignition map.
I'm planning to make a det cam during the week before making any change in the ignition table.
And maybe I'll also try E85 later. But than I have to remap fuel.

As I know CR is std. The compression test results are also prove it. (around 150psi)


But I think a std. GTT engine would det @1.4bar with the std. RE209, wouldn't it?

1) I saw the map, thats how I know you're a couple degrees away from the RE209

2) Detonation can be a bit hard to listen for on the C1J. It's not overly loud because it's wet liner. The OHV stuff can mask it a bit too. Make sure you listen to the cylinder head and not the block.

3) Compression doesn't directly relate to compression ratio. Cam choice, timing, valve clearance and a load of other stuff influence that too.

4) You'd probably be right on the limit with the RE209, but too many other factors get in the way to just say yes or no.

[Andrew Cooke]

do you have experience of E85? it'll eat untreated aluminium, if you don't have the right materials the insides of your fuel pump will clog your injectors.

[Fordy]

Stick with the best pump fuel you can get and leave e85 for the big boys to play with

Scoff, do you use the knock sensor location to listen on? or somewhere else?

[Sparkie]

As I know it is std. 73.5mm.

old standard was 73.5mm

the swiss had heads that were 74.5mm i think.

soon after all other heads sold by renault were 74.5mm.
allows for more skimming.- but reduced compression.

[Scoff]

Stick with the best pump fuel you can get and leave e85 for the big boys to play with

Scoff, do you use the knock sensor location to listen on? or somewhere else?

On the C1J always the standard location or one of the bolt holes near by

[Jimmy_GTT]

I have a brand new pump. My friend uses such a pump with E85 for quite a long time now.

I tought all the heads were 73.5mm. Good to know there are some 74.5mm.
But if the phase 2 heads are taller than the CR should be less then phase 1. Than how it can produce 5hp more? Where is the difference?

@Scoff
Thanks for all the useful info.
I will locate the det can on the original knock sensor position.
How reliable is the original knock sensor? Have you used it with an EFI mod?

Is there a law that if I change the cam from std. to sg. like the KTEC260 than I have to reduce or increase spark advance?

How shall I modify my spark table? Increase all the values above 100kPa 1 - 1 than test drive the car? What is the limit that I shall not step over?