cewrx7r1

iTrader: (2)

My abbreviated mods are:
Intake, M2 hard pipes with K&N filters.
Non-seq turbos with clipped turbine wheels.
Efini "Y" pipe set.
Blitz FMIC.
Greddy throttle body inlet elbow.
Secondary vacuum throttle plates removed.
Stock intake ports.
Ported exhaust.
Mind Train down pipe.
Shane Racing resonated MP.
HKS turbo cat back exhaust.
NipponDenso high performance fuel pump, 25% more flow at stock pressures.
1200cc secondary injectors.

Since the previous session, 2 degress timing has been add to most cells above 2800 rpm with a little more in the low spots in the torque curve. This has fixed most of them. The High end still needs some more timing above 6000 rpm.

Do to uncontrolled differeneces, power was down about 2HP from the previous session for the same setup. This is about normal. That is why I always start off with my last best run setup before making changes. This session netted 4.7 more hp for 2 degrees more advance in IGL.

I do not plan to do much more to the timing except for above 6000 rpm. This basicaly finishes my 12PSI boot testing. Next will be 14PSI.

My timing is hot by comparison to the two base k sets that we all have seen, but from what I have learned, especially from the single turbo guys, mine is really cool for my porting.

cewrx7r1

iTrader: (2)

My post dyno session maps are:

adax

iTrader: (2)

Thanks Chuck,

Did you add 2 just up to 12 PSI (if so, what row did you stop) or everywhere under boost?

In general, it's 1-4 degrees more advanced beyond 5200 RPM and 2-11 (8 average, although some areas are never used) more advanced below that under boost than the map I bought from XS for similar mods.

Alan

cewrx7r1

iTrader: (2)

The +2 was added across the board from N08 to N20 for P17 to P20.
Then some added for the transitional area of no boost to boost. Also added more advance for low areas in the torque band to bring them up.

To see what all I have done since getting the PFC, compare my IGL in the above set to the Houston set #1 non-seq which was my original given to Jason. It now looks more like the base stock set.

A large single turbo or stock turbos converted to non-seq do not build boost as fast as the stock twins below about 3200. Thus you can run more advance there to get more power. They also do not have spiking problems around 4500 rpm, once again more boost can be run there.

spyfish007

Looks good Chuck ... good to see your getting some use out of that wideband!

forcefed1

Looks great Chuck. Your maps are definatly the smoothest flowing. No little spikes or valleys that make no sense. Your maps are real good to study trends when I'm trying to figure out my own maps.
Thanks!

pweizman

Chuck -

Nice torque curve...

I have a few questions.

1. Do the clipped turbos make a huge difference in spool up time?
2. Do you have your turbos modified...i.e. NOT the poor man's seq? Ported wastegate?
3. How much of the torque curve is gained by the non-sequential turbos, and how much is because of your other mods?


Patrick

cewrx7r1

iTrader: (2)

Patrick,

(1)The main reason for clipped turbine wheels is to reduce maximum boost for non-seq use. Why, because even with the WG ported to the max, boost creep is a problem with the stock setup running non-seq and a MP. The turbos just overpower the WG. This is caused by better exhaust flow due to the non-seq conversion and to removal of the cat. The lowest boost I can sustain is about 11PSI. If you run non-seq with a cat, then you do not need to clip the wheels. With this change alone, I really did not notice any change with a cat as it was when I first started my conversion. I did the turbos first, then cat, then engine rebuild with the rest of my mods.

(2)I am beyound the standard full non-seq conversion. My turbo compressor outlets were ported many years ago by Pettit. This gives about 8% more flow with the stock snails. The WG is enlarge to the max for the stock WG flapper. I have slightly modded the turbo housing and exhaust manifold to also improve exhaust gas flow through them.

(3)Look at any seq setup torque curve below 4500 and compare it to mine. The seq starts off faster at 2500 but by 3000 I am taking off. Go to

http://www.micromanx.com/goble/rx7/p...3/compare.html ,I am making even more torque than Brian was. Brad's engine was a Ray large port engine. My ports are basicall stock.

(4)Most of my other mods are to reduce turbulance in the intake system which improves the flow rate. This means that the turbos have to work less for the same boost which results in a cooler intake charge. Now this does not benefit me in the cold winter months as the large IC isn't utilized to it's capacity. But when summer gets here, I have the advantage. The MP does affect all of the curve but more so in the low end, the less back pressure allows the exhaust to flow "faster" and increase spooling. SOME will disagree with this. It is not backpressure that helps the low end with exhaust gas scavenging, it is the velocity of the gases in the exhaust system that is important. The HKS tubo cat back has smaller pipes and more restrictions than many others. My combination does help, not all will. The PFS polished SS cat back would not help as it is 4" id through out with poor noise muffling.

Tim Benton

iTrader: (1)

The one good thing about the PFC is the staging of the turbos. Ray did mine and it comes online at 4300 rpms clearly 500 rpms before my old M2 stage 3 ecu. Looking at the link Chuck provided, my current setup makes more HP than Brooks, Brad, or Brian's car up to 5K. Now above that I'd assume they will make more than me since I remember Brooks being in the 350 rwhp range with the same for Brad's. (Brad every get another 3rd gen after he found his stolen car?)
Heck its easier to just post them in
3000 130 rwhp 230 ft/lb
3500 160 rwhp 240 ft/lb
4000 180 rwhp 240 ft/lb
4500 220 rwhp 258 ft/lb
5000 260 rwhp 270 ft/lb

My current setup is stock engine and stock seq turbos, DP, resonated MP, and PFS cat-back (mine's only about 2.8" inner diameter, 3 in outer dia piping). add the other things like lighter flywheel, hks ignition, and M2 IC and intake and PFC.

Tim Benton

Tim Benton

iTrader: (1)

looking at their dyno graphs, Brad and Brooks both did since I topped ou at 326 rwhp at 12.5 psi (boost gauge value). with my torque being 278.

Tim Benton

cewrx7r1

iTrader: (2)

Tim,

Good numbers also. Have you changed your maps since they were posted, and can you post your dyno?

Tim Benton

iTrader: (1)

Sure, I'll scan it in and try to attach it in the test page first then bring it over here.

As far as timing, I did like you, although I don't have a wideband, and raised the timing a total of 2 degrees in pressure cells 17, rpm cells 5 through 20. My knock number went up a total of 10 point from high teens to high 20's so I'm comfortable with that knock number for now. I've also taken out a small percentage of fuel in those same cells since I was in the 1.05 range on the stock 02 sensor. Small percentage being around 2% is all. I'm not going to take out anymore until I have the wideband at the dyno hooked up next time to be sure.

Tim Benton
I'll post the dyno sheet in the next day or 2.

Johnny

Yes he did..he tracks..Jim O'Brian's old car now...

Wade

iTrader: (1)

This is a great thread. There is a lot of value to someone making small changes on a dyno and measuring the difference, as well as paying attention to the details of his tuning. Excellent work by Chuck.

I think the info in this thread is a good argument in favor of sequential turbos.

The sequential obviously has the advantage in the low end, IMO this is caused by the "dynamic exhaust manifold" closing off the path through the secondary turbo before transition, which means the exhaust gas through the *turbos* is higher (same volume going through a smaller path). Contrary to what Chuck believes (and as he said, some will disagree with him), I don't think putting a more restrictive exhaust downstream from the turbos is beneficial to spool up. Adding a restriction downstream of the turbos will only slow down the exhaust velocity in the turbos themselves.

This thread is also helping to establish that the nonsequential conversion makes little, if any, improvement in high end power.

I think the only reason someone should consider the nonsequential conversion is simplicity and a smoother power curve, at the expense of some power and response in the low end. I think the notion that a proper non-seq conversion improves high end power is not well established at all.

I hope this doesn't start a tangent. I don't want to shift the focus of this thread.

Wade

Tim Benton

iTrader: (1)

What exactly, in the non-seq. conversion, opens up the flow. If all you are doing is wiring the port open and not closed, I don't see how anyone would think it would help top end since the charge air is still flowing through the same piping as the seq setup. It's been awhile since I was on the big list and ever thought of doing this mod, so I can't recall the specifics of what all is done that could change the flow characteristics of the air coming from the turbos....like we know the efini ypipe flows better since it takes the hose opening out of the way compared to stock, giving it a bigger path to go through.
Just asking since I can't remember.

Also just thinking about it, I was dead set on not ever getting my throttle bodies ported because I didn't think it would really help the flow any more....helping reduce pressure loss..etc. But if the efini y pipe, with its better flow characteristics, can add HP as many have shown, myself included with an increase in boost from the freer flowing path...then wouldn't the same hold true with the larger ports on the throttle body? Am I thinking of it wrong? Or maybe nobody has really done the mod and dyno'ed their car or spent 400 plus bucks on a mod that might add 10 hp or some other hypothetical hp number.

Tim Benton

Tim Benton

iTrader: (1)

I should say, wiring it open so it won't be able to close in the post above concerning the non seq conversion.

Tim Benton

Tim Benton

iTrader: (1)

What's Jim driving now?

Tim Benton

Tim Benton

iTrader: (1)

As far as MP helping more down low....as Chuck said above....I'd have to kindly disagree as well. My MP really did nothing for the HP and torque curve until after about 5700rpms. I'm actually a couple HP and ft/lbs lower with the MP in place below 4500rpms when compared to my hi-flow cat run. Wael's web page shows the same type thing where he was making more HP and torque in the low end with the hi-flo cat and then the MP really added the HP and torque in the higher revs where you don't want the more restrictive hi-flow cat impeeding flow as the engine is trying to push more air out the exhaust...stifling flow. If I've misread Chuck's post I apologize and this only applies to my car and Wael's car since all cars are different and Chuck's might have shown improvement in the lower revs with the MP.

Tim Benton

cewrx7r1

iTrader: (2)

From what I have seen and experienced, seq turbos do give more initial torque at the real low revs which are good for tooling around town like you are driving a V8. But if you are a real gear banger, by 3500 non-seq is better until redline. A full non-seq conversion removes the turbo control gate and opens up the exhaust more thus should have a little more at the top end. I have full 12psi boost by 3400 rpm.

My last dyno shows that my top end needs more timing work due to the unnormal drop between 6500 and 7500 rpm. I am adding more timing there like the XS 04 maps have.

My dyno runs were also made with low 11s AFRs. From what I have learned, you need closer to 12s AFR for good power, any lower kills it.
I also noticed that the GOOD linear O2 sensors all tell you that you are running leaner than you thought. Thus when the instructions say to tune for 12.5 down to 11, 11.8 is the middle. Ray's original fuel gave me 12.1 to 11.8 and I richen it up by 4% to drop it to 11.8 to 11.4. Then I added another 1.1% for my dyno runs for safety. I will be removing some full.

I also have seen some dyno runs posted for about 325Hp for stock ported engines at 11 to 12 psi boost. When compared to some street ported engines with stock turbos, these values seem too high, unless they are running on the edge. I am sorry Tim, but I really do not believe your dyno numbers as being "SAE corrected" unless your engine has been tuned to the max since your maps were posted. My last dyno run was over 320rwhp but that was not sae corrected.

I will say again, science has proved that more back pressure does not produce better low end power. Sports Compact Car had an article about exhausts a while back and explained why and how some get confused over this. It is a deception caused by other factors.

Wade

iTrader: (1)

Tim,

The "proper" non-seq conversion also involves removing the CCV completely, removing or wiring open the TCV which allows large porting of the 2ndary turbo exh path, and also other porting/removing some other parts while off the car. Obviously some of this can be performed on a sequential turbo car, some can't. For example, I opened up the 2ndary path and TC flapper significantly and matched the ports on my sequential manifolds, however the TC could have been enlarged even more with a non-seq setup.

So there is a potential for more porting work with the non-seq setup, though IMO compared to a well ported sequential setup the difference would be very small or unmeasurable (meaning, the difference between the two setups would probably be small enough to be considered "within acceptable variance of dyno runs.")

As far as the Efini pipe being worth some HP, I have never seen a dyno before and after with the boost kept constant. Sure, if you got another PSI of boost and didn't change anything else, you would probably gain power from the boost increase. I think if everything else was kept equal, the efini pipe would be worth no more than about 5 hp. It is a very small change in a system with LOTS of resistance.

I think there would be a similar (or less significant) increase in power in most FD's by porting the TB.

Wade

Wade

iTrader: (1)

*Literally* a couple horsepower and ft/lbs lower? If it is less than 5hp then I would discount that. 1/2 a psi of boost would cause more of a variation than that.

I don't think Wael's tests are valid because from his midpipe dyno it is clear something else is wrong with his car. Look at the way the torque bounces around. There are 3 distinct spikes of torque.

Not to say that I think the midpipe doesn't hurt the low end, it might, I have nothing that can prove one way or the other. I do think the benefits of a midpipe over a cat at high rpms are pretty well established and pretty easy to feel even with the butt dyno.

Wade

Wade

iTrader: (1)

Chuck,

I agree about non-seq having a theoretical better top end, I just haven't seen any evidence to support the non-seq flow enhancements actually pay out.

As far as power at 12psi. There are a lot of factors that can cause a variation in power between cars. There seem to be plenty of cars out there at 12psi that are making in the 325 hp range. Timing might be playing a role, since most people with the PMS run about -1 degree for every 1 psi of boost over 10, this still leaves the timing pretty advanced compared to your current PFC settings. I think the stock replacement ECU's run pretty safe timing and fuel for the typical mods, though I haven't personally verified this.

I wonder if your initial maps were a little leaner (and they might not be on some other cars) because your fuel pressure seems a little low compared to other cars? A few people reported on the forum that with a better pump and the stock regulator they were getting about 10psi more fuel pressure, I think you said your pressure was right at factory specs.

Wade

cewrx7r1

iTrader: (2)

When I built my engine last spring, I used "all new": engine wiring harness, coil pack harness, 550cc main injectors, 850cc enlarged to 1200cc secondary injectors, fuel pulsation dampener(FPD), fuel pressure regulator(FPR), and RP's NIPPOD upgraded fuel pump. My fuel system is better than stock new with stock pressures and 25% more flow rate. The PFCs should be programmed for stock fuel pressure unless you told the dealer otherwise.

Tim Benton

iTrader: (1)

I have 2 dyno runs to scan in....one that shows the MP/hi-flow cat comparision...made 320.9 rwhp with it at the 12.3 --.5 or less on the autometer (below the halfway "area" between 12 and 13 psi) since thanks to Chuck's diligence, we now know the value it displays IS lower than the number it is actually gets from the map sensor. The newest dyno run with the 2 degree advanced timing and 2% fuel taken out resulted in the 325.3 reading...although the numb nut running the other dyno couldn't get a good reading off the wires (hell, we had 2 inches of rain and 1.5 were in the shop floor with the connectors laying in the water submerged) so its plotted against speed and has no torque numbers.

Tim Benton

Tim Benton

iTrader: (1)

I hit the submit button before I finished. Chuck, both dynos are dynojet that show corrected SAE HP and torque...although the second dyno doesn't show torque. The 320.9 run was done in 85 plus degree heat, high humidity here in the Atlanta area in summer time. Correction factor was in the 1.03 to 1.04 range. The latest was done also in the Atlanta area a coupe of weeks ago....temp was in the high 40's but it was raining so again high humidity. Granted you might be right an I'm running close to the edge of whats safe and near the "edge"...although my new O2 sensor is still showing .97 at WOT at 4 gear 7K to 8 K range....that's why I'm going to have the next dyno session with the wideband hooked up so I can see how close I am running to the edge. Granted I hope I'm not since a new engine isn't something the wife would like for me to say. I do look forward to plotting my stock O2 sensor number to the wideband number and see what it correlates to in so far as my car is concerned...since all cars are different. I'll see if the .86 number that Peter F. said to shoot for is actually to lean for my car or if its safe or still too rich. Either way, going to the dyno is fun as hell and when you actually get some good data from it, it makes it even better

Tim Benton