Topic: Bigger turbo, more aiflow but not more HP?!

[Kelu]

The case:

Stock turbo + catless downpipe + Solo Mach Cat-Back + IC ... airflow maxed around 31-32 lbs/min ... dyno estimated 312hp (in two sessions one year apart)

Big turbo + Garret casted exhaust manifold + custom catless downpipe + same cat-back + same IC ... airflow 40-42 lbs/min ... dyno estimated only 320-330 hp
Bumped the octane of the gas ... increased the timing from 12 up to 15-16 degrees advance .... dyno estimated 350-360hp

Dyno was same in all cases, almost same conditions, AFR pretty same, a little bit leaner with big turbo tho

Those values with big turbo would scream 400hp based on my estimations and I though dyno is bugged, took it to a drag race on a track where I raced many times and it confirmed that the power is correct, dropped only 0.2-0.3s from my stock turbo runs.

I don't get it, not sure what is happening, those values are normal? If is getting so much air, why is not producing power even AFR is leaner and timing same or more?

PS. I have data to back this up if is the case.

[elff]

Kelu

How does this new turbo of yours compare to the 2871 kit offered by DDM which is the Garret 2871 machined into the exhaust housing of the K04?

The reason I ask is this turbo will be 360+hp with 93 Octane depending on tuning and I know my tune hit almost 42 lbs/min of airflow

So with a stingy Dyno and a comparable turbo, that could be correct.

[Kelu]

The turbo is way bigger, is bigger than a GT35, it was a custom order for my local tuner, the guys from COMP said is capable of at least 700HP, even so it spools pretty well for my stock engine.
I boost 15psi (1 bar) around 4000-4500rpm and reaches maximum allowed by EBC of 23-25psi (1.6-1.7bar) by 5000rpm and keeps that boost until 7000rpm with no problem.

Tune was not worked too much for this turbo, even the guys who made this turbo said that at that boost it would push at least 450hp on a 2L engine.

[elff]

Then it does sound like a tuning issue but that's beyond me.

I don't think the manifold would be an issue before 400hp, any chance the down pipe is more restrictive?

[LatinVenom]

I have to agree with elff, something is wrong with the tuning.

[Arabas]

i also believe it has to do with tuning.
you said it yourself, tune was not worked too much for this turbo.
also, 1 bar at 4000-4500rpm seems a bit low..

[Kelu]

I don't think the manifold would be an issue before 400hp, any chance the down pipe is more restrictive?

Downpipe is way larger because I have an extarnal wastegate now. Mechanic suspected my cat-back but spoke with Jeff from Solo and he said should be good for 400-450hp at least.

If is about back pressure I would check manifold or turbine housing because is small for that compressor for faster spooling.
Here is some pictures with the turbo:

[SHiNY]

That is one SEXY turbo Kelu!

[miller11386]

Do you have a log we could look at?

If your pushing more lb min, your timing is greater, and AFR is consistent with 12.0-12.5, I am curious what your IAT's look like.

If your IC is the same and you are trying to blow more air through, perhaps the temp is rising due to the intercooler. I know a lot of people in the states have issues with "ebay intercoolers" that dont flow /cool very well. Also I know some sky peeps who had to get larger IC pipes to accommodate the flow and efficiency and saw power gains by increasing the diameter of the IC pipes.

[Kelu]

That is one SEXY turbo Kelu!

That is one of the strangest replies, even if is coming from you  .... is still  for me, maybe for men a turbo can be sexy because it means more power or because it has many holes  but coming from a lady 

miller: I can post logs but first i need to search for them in my laptop 
The dyno room has a pretty good and constant in temperature, the air blower is huge, simulates speeds 100-150 km/h, i barely stand in front of it.
I doubt is IC or IAT, I would have noticed, IC is not an ebay one, is Dejon and has been tested in last 2 years in races even at outside temps of 100F and it did a great job, ic pipes were cut big time to accomodate the new turbo outlet compressor and MAF relocation on cold IC pipe.

[miller11386]

well if its not pressure lost/ temp gained across the IC, your timing is advanced, and you have a cool IAT, I am at a loss as well.

Perhaps a leak? However I would imagine the car would see a leak at WOT.....

How hot is your EGR? and is it simulated or an actual reading?

[Gentleman Jack]

Did you forget to remove a shop rag and it is now stuck in the IC?

[SHiNY]

That is one of the strangest replies, even if is coming from you  .... is still  for me, maybe for men a turbo can be sexy because it means more power or because it has many holes  but coming from a lady 

How sweet, you called me a lady. I think I love you!

But yes, more power is sexy, even to ladies.

[elff]

The great thing about that comp turbo is the first picture.
The bolt on the turbine is clearly attached!!!

[Critterman]

BAD ELFF, ground yourself for the weekend!

[elff]

Compared to the EFR, that's a huge thing!!!

[Dave@DDMworks]

Did the intake change when doing the install? If so, from what to what?

What are you using for the calculated hp? Or do you have actual runs on the dyno?

Do you have any way of measuring pressure at the outlet of the turbo and compare that to the intake manifold pressure?

Did you find a log yet?

And that thing is a beast!

[Sol Asylum]

The great thing about that comp turbo is the first picture.
The bolt on the turbine is clearly attached!!!

I was thinking the same thing.  That and he should safety wire the nut to the housing so that it can't come free on it's own.

[POS VETT]

Did you add more fuel ?

[Kelu]

well if its not pressure lost/ temp gained across the IC, your timing is advanced, and you have a cool IAT, I am at a loss as well.

Same here 

Perhaps a leak? However I would imagine the car would see a leak at WOT.....

Leak where? should be visible somehow on the logs IMHO

How hot is your EGR? and is it simulated or an actual reading?

EGR in our cars is calculated, you can see on HPT logs

The great thing about that comp turbo is the first picture.
The bolt on the turbine is clearly attached!!!

Hahahaha, that was the thing which I spotted when posting this pictures too 

Critterman: Naaah, he is funny

SA: Stop jinxing 

Did you forget to remove a shop rag and it is now stuck in the IC?

I wish to be so easy

How sweet, you called me a lady. I think I love you!

But yes, more power is sexy, even to ladies.

You think only 

Did you add more fuel ?

Our ECU has AFR tables only, than it commands how long the injectors are staying open to fulfill the requested AFR. Short answer: Yes

Did the intake change when doing the install? If so, from what to what?

Airbox removed completely, using a huge air filter now, MAF relocated on the IC cold side.
http://www.modifiedm3.co.uk/ITG-filter.jpg

What are you using for the calculated hp? Or do you have actual runs on the dyno?

Dyno runs, here are some:
[attach=1]
[attach=2]

Do you have any way of measuring pressure at the outlet of the turbo and compare that to the intake manifold pressure?

We have to drill and we are planning to do it in March. My local tuner suspects maybe turbine housing.
Outlet of the turbo you mean right after turbine outlet (downpipe)? Or compressor outlet?

Did you find a log yet?

Yes sir:
[attach=3]
[attach=4]
[attach=5]

Here are some log:
[attach=6]
[attach=7]
[attach=8]

And that thing is a beast!

Is big but ... it is not delivering power ... 

[Sol Asylum]

Kelu if you safety wired the nut to the housing then either the nut would come off or the turbo wouldn't spin.  So not a jinx just a joke, which I would have thought at least GJ would have gotten.

[shabby]

What are the specs on that turbo, hitting 20psi at 4500rpm in 4th gear makes me think you've picked one that's too big.
Your afr is way too rich go back to 0.87,  you might have a possible leak in the ic pipes or between the manifold/turbo. Pressurize the ic pipes to find a leak, it wont show in the logs since your maf is close to the throttle body now and a leak could be at the bov or on the intercooler. Look for black soot near the exhaust manifold/turbine, perhaps the gaskets aren't sealing well.

[Kelu]

What are the specs on that turbo, hitting 20psi at 4500rpm in 4th gear makes me think you've picked one that's too big.

The turbo is big, but not by mistake

The turbo is way bigger, is bigger than a GT35, it was a custom order for my local tuner, the guys from COMP said is capable of at least 700HP, even so it spools pretty well for my stock engine.

Your afr is way too rich go back to 0.87,  you might have a possible leak in the ic pipes or between the manifold/turbo. Pressurize the ic pipes to find a leak, it wont show in the logs since your maf is close to the throttle body now and a leak could be at the bov or on the intercooler. Look for black soot near the exhaust manifold/turbine, perhaps the gaskets aren't sealing well.

I went  little richer because of 16 degree advance, we played a little and leaner with less advance was not so good, small KR started to appear up top IIC.
A leak between turbo and intake I think it doesn't matter because MAF is right before thottle body and MAP is on intake manifold, so airflow and boost are read AFTER the leaks and that wouldn't make a "power loss".

I will check for leaks in intake and exhaust air stream, just waiting this weather of -4F to pass for more than 2 weeks.

Oh btw, spark plugs where new and regapped.

[Ames Performance Tuning]

Hi Kelu,

Have you checked your low pressure fuel pump under load to ensure it is about 55 psi?  Does it look like you are spraying outside your optimal fueling window?  Have you regapped your spark plugs tighter?  I had a problem with my fuel pressure regulator that caused low pressure fuel issue and reduced my power.  Once that was fixed, I could not go over 33lbs of air without regapping spark plugs.  These items may not apply but did in my situation.

[Kelu]

Hey BrentnKC, interesting approach.

About spark plugs: they are one step colder and regapped tighter, learned from other modded LNF with more than 400hp. The plugs did a nice job, not too much KR even on that airflow, 23-25psi, and 16* advance instead of 12* stock. If they were improper some KR should appear, right?

I looked over fueling aspects on the logs too, the injectors are staying open 6ms, the limit is around 9-12ms iirc so there is a lot of room, also the AFR it doesn't go too leaner compared with the commanded one. If High Pressure Fuel Pump or the Low Pressure Fuel Pump had any problems or not delivering correctly injector would be commanded to stay open more time and AFR should go lean compared with the commanded AFR, right?

Doesn't seem that airflow is limited tho, hits 40-43 lbs/min.