My 1991 Talon TSi Compound Turbo AWD

[pgfpro]

I thought I would start a thread about my Talon that will be capable to run in lean burn at 30+:1 A/F ratio's. Now because the Talon never was a lean burn vehicle all testing with lean burn will be off road.

I'm running a ECM Link engine management system that lets me have control over all the engine parameters. It also gives me the ability to data log up to 4 hours.

Engine:
2.0L
modified 1g turbo pistons, with spray-guided crown.
modified head, spray-guided high heat direct port.
custom camshafts.
intake manifold, high heat direct port w/adjustable port angle injection.

Turbo System:
High-pressure 13g internal gate dump to atm.
Low- pressure FP Red BB,rear mount.
DNP Turbo exhaust manifold.
44mm Tial Bi-Pass waste gate.
FMIC 3" core.
Tilton 40-527 external oil pump
Jegs 12V Vacuum pump

ECU:
ECM Link Engine Management system

EGR:
Electronic controlled cold EGR system.

Transmission:
Transtar/IPT 5 disk front clutch kit in stock basket, Transtar/IPT end clutches, double up stock flexplate, John Deere HyGard fluid, Foreign Muscle DSM (Transmission Control Unit), EPROM Upgrade full line pressure with pre-set rpm shift points
2g lock-up converter

Last years testing I found out I can run at freeway speed around 60 mph and be at only 0.81 inch/hg to 1.58 inch/hg at 30:1 A/F. One negative result of running very high load for long periods of time is that I would loose vacuum for the brake booster. So this year Im running a Jegs 12v Vacuum pump that can activate by engine load or manually. This will fix the brake problem.

The other new addition to my car will be a high heat direct port w/adjustable port angle injection. This will give me the capability to run up to 250*F direct port air injection. The air injection nozzle sits about 3 inches up-stream of the fuel injector outlet-tip.
All this hot air begins at the high pressure turbo's compressor outlet. I tapped the compressor outlet with a -6AN fitting and copper line. This then goes to my #1 exhaust header pipe, that wraps around five times, then feeds between the header and head to my #4 exhaust header pipe that wraps around it five times also. The copper line is insulated and then goes to a tee in which feeds the direct port system from both sides to keep air flow even. This very simple high heat system eliminated my over complex swing gate heat system.

I also built a "Cool Air EGR" system that will be controlled by my engine management. This will be right after the T/B and feed all four cylinders. Plus the way I built it I will be able to data-log exhaust pressure at the valve itself.

This weekend I should have the engine compartment painted.
Next weekend have the head and intake back on.
The weekend of May 10th start the engine on the high pressure turbo only.
The week of May of May 17 have both high and low pressure turbos enable.
Then start the body work on the outside in which I should have it show ready by the first of June.

[pgfpro]

Chart time:


In the above chart is some data from my logs of my car last year.

The engine is a 2.0L 85mm bore, 88mm stroke

The lowest line in the graph is at 3000 rpm

-9.36 inch/hg or 68 kpa (L) more pumping loss
3.94 lbs/min of air (N/A)
12.81 bsac (L) less power from air
25 engine cycles/sec (L) greater pumping losses, lower kpa at the intake valves
21 a/f ratio (L) raises pumping losses
15.7 whp (L) more power needed for higher mph
0.61 bsfc (L)
28.8 fps piston speed (W) great air/fuel mixture
35mpg @ 66mph (L)

The middle line in the graph is at 2350 rpm

-1.59 inch/hg or 95 kpa (W) less pumping losses
3.13 lbs/min air (N/A)
16.80 bsac (W) more power from air
19.5 cycles/sec (W) lower pumping losses, higher kpa at the intake valves
30 a/f ratio (W) lowers pumping losses by increasing higher load needed for the correct fuel amount for power output.
9.5 whp (W) lower power needed for lower mph
0.56 bsfc (W)
22.6 fps piston speed (W) fast enough to promote good air/fuel mixture
53mpg @ 53mph (W)

*Comparing between the two lines.
(W) win
(L) lose

Now there is the third line, the highest in the graph at 1200 rpm. FAIL

-1.02 inch/hg or 97 kpa (W) low pumping losses, great kpa at the intake valve
10 cycles/sec (L) very low air velocity killing air flow, and causing reversion
11.5 fps piston speed (L) major knock, from slow power stroke, and heat adsorbed into combustion chamber cylinder etc.

This is my goal for this year.
3000 rpm @ 225*F+ IAT
-0.01 inch/hg or 100 kpa (W) no pumping loss
4.53 lbs/min of air (N/A)
14.7 bsac (W) more power from air
25 engine cycles/sec (W) high air velocity, no pumping losses, highest kpa at the intake valves
30 a/f ratio (W) lowers pumping losses
15.7 whp (W) more power needed for higher mph
0.49 bsfc (W)
28.8 fps piston speed (W) great air/fuel mixture
47 mpg @ 70 mph (W)


I'm building a high temperature air injection unit that will inject air 3" in front of the intake valves. I will be able to adjust the injection injection angle at the intake port. I'm also building a adjustable cool air EGR flow valve. This will be up-stream from the high temperature ports. My EGR system will will have its own cooling system so I will be able to control EGR temperature.
On my car the stock EGR was just along for the ride. It never was enable from the factory. The 1991 California Talons were the only cars with active EGR systems.
In this pic you can see EGR, its outlet is at 6:00 O'clock at the bottom of the T/B placement.



I also have a electric vacuum pump that will keep the vacuum brake's happy so I will always have a stock feel to the break-pedal.


Intake port runner, showing injector angle. Air injection directed at fuel injector fuel flow path about 3" upstream.

[pgfpro]

Update 1: engine compartment is sealed and ready for Black Cherry Paint.




Update 2:
Engine compartment is painted.

[pgfpro]

I started working on my front belly pan, and now I have a question???

I'm thinking about cutting a hole or two in the back of my hood to let air escape the engine compartment? Last year I ran a front belly pan and had over heating issues at freeway speed? Do you guys think this would help???

Here's a picture of my other Talon's hood. I'm thinking about two holes at the back side near the rear corners???

[pgfpro]

Some info on "Exhaust Blow Down" from one of my F1 friends that he posted on a F1 forum on how today's F1 turbo compound power units are now the most efficient F1 engine ever.

extracted energy does not necessarily mean back pressure

because there is lots of energy in blowdown (the exhaust 'pulses') ie between EVO and BDC
a very useful amount (eg 10-15% to crankshaft power) is extractable without any increase in exhaust pressure after BDC
as stated by Wright, who made 14000 such aircraft engines in the 1950s
so can be called free energy

why is it free energy ??
the turbine work is not seen by the crankshaft as an additional impediment
because blowdown is a choked process, with great loss of useful pressure/velocity energy
choked by the exhaust port, not by whether there is an exhaust turbine or not
the energy extracted by the turbine is simply energy that would otherwise have been dissipated by more supersonic (shock) flow

greater amounts can be extracted if exhaust pressure after BDC is allowed to increase
this again reducing blowdown losses
in the 1940s it was shown that BTE was improved this way (improving total power for a given fuel quantity in 2014 F1)
even if exhaust pressure exceeded induction pressure (as long as the EVC was suitable for this ie relatively early)
this can also be called free energy

these two routes seem in principle complementary (though realisation of this would be design dependent)
Tommy Cookers

LINK:
TERS : Thermal Energy Recovery System - Forum - F1technical.net

[Superfuelgero]

Originally Posted by pgfpro

I'm thinking about cutting a hole or two in the back of my hood to let air escape the engine compartment? Last year I ran a front belly pan and had over heating issues at freeway speed? Do you guys think this would help???

No, the back of the hood is a high pressure zone. It would want to flow in, not out.

Some vents can be done at the leading edge, or better yet, into the wheel wells.

Your exhaust blow down reminds me of compound steam engines, and is used in high efficiency turbines. Increasing the stroke (relative to bore) also accomplishes some of this.

Buschur might be able to help if you want to forgo the vacuum pump and electrical load.

[pgfpro]

Originally Posted by xntrx

No, the back of the hood is a high pressure zone. It would want to flow in, not out.

Some vents can be done at the leading edge, or better yet, into the wheel wells.

Your exhaust blow down reminds me of compound steam engines, and is used in high efficiency turbines. Increasing the stroke (relative to bore) also accomplishes some of this.

Buschur might be able to help if you want to forgo the vacuum pump and electrical load.

Thanks Man!!!

I was having a space moment. lol

I might do what the new EVO's are doing, and put a triangulate hole in the hood at the front. This will also help with getting hot exhaust manifold heat out of the engine compartment?

I got a ton done today but my body is paying for it.


The head is on and the cams and intake are installed.

[RobertISaar]

i'm..... curious, what kind of advance are you having to run with AFRs that thin? even with excellent mixing/air-fuel charge control, seems like flame speed would be super slow running twice as much air as stoich?

[pgfpro]

Originally Posted by RobertISaar

i'm..... curious, what kind of advance are you having to run with AFRs that thin? even with excellent mixing/air-fuel charge control, seems like flame speed would be super slow running twice as much air as stoich?

Very good question.

I'm running around 30* ignition advance at 30:1 A/F.

It's a major balancing act trying to keep the A/F ratio lean enough to help with pumping losses, and not slow down the flame speed to where the power drops off and kills efficiency. This is where I found out after a couple try's that I need to introduce flow to the top of the heads intake runner to create a tumble air flow effect. This help a ton with flame speed. I was running around 38* advance before I made this adjustment.

The other thing I found out is the extra back pressure from the turbo help the blow-down and improved efficiency. As flame speed slow down from lean burn the extra exhaust pressure pulled more power out of the later part of the piston power stroke.

[Superfuelgero]

Part of the back pressure is also encouraging EGR (increased pressure differential).

Where are you at with the camshaft advance and separation?

How are you reading the afr? Most o2's i've seen max at around 27.