Build thread

[speedjunkie]

Great numbers! Now let's see some track times

COLORADO FD super tuning battle of peace! FDEEZ/DwDuc/SpeedJunkie/lOOkatme/$crillator (and anyone else that wants to play) massive blowout!

Oh I plan on getting some track times lol, and a lot of curvy road fun too. And I'd LOVE to do a super tuning battle, but we have even more FDs now, and we'll have more FCs soon too. I don't know of any FBs or SAs moving into town though so Chris is going to be lonely lol. But Jesse just sold his recently. I wish I'd had mine back on the road before he did. I can't wait to cruise with everyone again. Just with all the FDs we have here we could have something like an Options track video...assuming we're all running at the same time of course lol.

I wouldn't be disappointed with those results. With our power-to-weight ratio, that's nothing to sneeze at. Besides, more (expensive) things start to break when you start to fiddle around the 600whp territory.

I'm all in for that battle of 7's. I'll even remove 4 spark plugs to make it a fair race, j/k

Yeah it's really not bad considering power to weight. And that's true, I don't really want to get close to 600 and all the problems that start with that, but around 500 wouldn't be bad either lol. I'm really pretty happy with the numbers. I guess I just expected a little more is all, considering all the new mods...AEM coils, race plugs, HE crank trigger kit, more capable ECU, etc. But I guess those would be more along the lines of reliability mods for the most part. I'm still not completely convinced the stock ports are what is holding it back. And I'd really like to see the ignition breakup issue resolved, hopefully he's working on that. Considering all the extra legwork he's done, I'd imagine he is, but he didn't say.

OK I'm down for that haha. Remove four, and then if you're slower just add two at a time until we're all the same LOL. And if you're not slower, it's fair lol. Uh oh, I'm starting to sound like a socialist lol.

[JTurton7]

I think I speak for everyone when I say. We need a dyno video!

[speedjunkie]

I think I speak for everyone when I say. We need a dyno video!

I agree, but I don't think there is one. I'll ask him for sure. If not, I plan on getting it on a dyno up here anyway and I'll get a video then.

[speedjunkie]

I had some email traffic back and forth with Chris today. BLUF or TL;DR: I may still be able to make more power lol. There are some other things too, but...whatevs. It's late and I'm sleepy lol. Ok cliff notes...I have to exchange the ECU at some point because the one they sent is only set up for one knock sensor and they need to write the code still for dual rotary knock sensors...the fuel pressure fluctuation is still there but not as bad, so we're looking into it...there is some turbo efficiency talk and talk about the issues with ignition breakup...and he's going to take it to a Dynojet to see if he was right about those numbers too. That's the big stuff. It's a good bit to read lol.

Want to give you a run down on Saturday. Everything went pretty well. I was very happy, surprised even, at the power it made on the ethanol. I was disappointed we couldn't make a clean pull at 24 psi as I'm sure that would of put us over the 500 whp Dynojet number and that would be pretty shocking, IMO, for this turbo. Power numbers on gasoline were about what I would of expected.

The fuels used were E10 and E80. I think you dropped the car off with E0. That will be fine to run. True E85 will be fine as well but I wouldn't run E98 without adjusting the mapping.

At 20 psi the turbo was running 123k rpm at 7500 engine rpm. That puts it well to the right of its efficiency range on the map. Adding boost would actually push it into a more efficient area but I think you'd get well into an overspeed situation. And you would still be well out of the peak efficiency range. I went back and read through your 7670 thread on rx7club and Geoff at Full-Race even suspected that you'd need to taper boost down at high revs to control turbo speed. While I'd love to run it at 24 psi, I think the writing is on the wall that it's just going to be well out of it's efficiency range there and, even if it makes good power, you'll be doing the turbo no favors.

Not sure why we had ignition breakup at 24 psi. It was very strong at 20. I had made some sweeps earlier at lower boost with the fuel very fat, in the 9:1 range, as I was trimming in the fuel, and it had no issues lighting the fat mixtures. Not sure if the heat of the day, heat of the engine, and location of the coils started to take its toll or not. That's the only idea I have. I could of tightened up the plug gap and tried again but I was out of time and, in retrospect, 24 psi maybe isn't a good idea anyway.

We still have the fuel pressure issue with the new regulator. I don't see it on the gauge in the car but it's showing on both the sensors at the back in the logs. My worry is that the gauge in the car is filtered and isn't showing what is actually happening. My hope is that what the sensors in the back are seeing is localized there, somehow, and isn't happening in the fuel rails. I really have no idea why it's happening or how to fix it. I'd suggest either adding a temporary sensor at the rail or tapping into the existing sensor and logging it with the ECU to see what's happening up there. The relative pressure, fuel pressure minus MAP, is more stable with the new regulator and the fluctuations under load are less than they were with the Aeromotive, but they're still there. Just had a thought that maybe the MAP reference location for the regulator has some weird harmonics going on that is causing the issue? In the end, the oscillation is such that the average pressure is really close to correct and it doesn't seem to effect performance.

At some point the ECU is going to need to be exchanged. I hope to get that done before the 6th but not sure that will happen. Syvecs didn't tell me the ECU I received was only built for a single knock sensor. It was an early board that wasn't setup for dual knock. They've said they'll exchange it for a new one but the rotary code for dual knock sensors isn't ready yet. They're working on it and it shouldn't take long but I'm not sending this one back until I know I can get a replacement immediately.

Would you care if I took the car to another shop and made a couple pulls on a Dynojet to confirm the numbers in Dynojet speak?

Yeah I'm disappointed also, but I guess 24psi is out of the question anyway haha. I was running 24psi before on pump gas with water injection, but I didn't have a way to measure the efficiency or speed of the turbo. By the way, have you noticed that when you're just before boost that the turbo makes a high pitched noise? I forgot to mention that before. It's done that the whole time I've had it and I never knew what it was. The manifold has the turbo canted forward about 5 degrees, but I'm not sure if that's contributing or not.

I believe the only thing we have available out here is E85, at the pump anyway. I don't plan on seeking out any other mixture haha, so that shouldn't be a problem.

I was told before that about 25psi was just beginning the efficiency range, but maybe I misunderstood. I was looking at stepping up to the next size 8374, but that will probably be a while. I don't feel like changing everything right now to run that turbo, I just want to drive it again.

I'll type out more later, I'm at work right now, but no I don't mind if you take it to a Dynojet as well.

Pressure isn't the issue with the turbo. We're only at about 2.4 pressure ratio at 20 psi. Peak efficiency is up to 2.8. As I said, increasing the pressure ratio (more boost), if we could somehow do that without also increasing turbine speed, would actually put the compressor closer to its efficiency range. But, if you increase pressure, it takes more turbine speed to do so. The compressor simply doesn't flow enough mass to sustain more PR without being overdriven.

Here is the compressor map of the 7670. The red dot all the way out on the right is where we're running it at 20 psi.

I'm going to wrap the coils in heat reflective tape and see if that helps, or build some kind of heat barrier around them. I'll tighten the plug gap if you think that'll help, and I'll try some different things but I won't see whether it fixes the issue or not. Those coils shouldn't need any help from other components, right? Shouldn't they be able to do this job on their own? Like no kind of spark booster or anything?

Hmmmm, that fuel issue is pesky. I wonder if it's because the sensors are directly after the filters and hopefully the flow smooths out as it travels towards the front. Or maybe they're so close to the pumps that they're picking up fluctuations from them. I can hook up the vacuum hose to the end of the LIM to see if that helps too. Maybe this is what we see when there is no FPD in the system, but I would think the FPR would take care of that. I would imagine that no gauge I have is fast enough to show what it's doing if it's the same at the rails, especially that digital gauge, and that only the ECU will show that. I'm willing to try whatever though. What type of connection do you have on the wiring for the sensors on the back? Is it something that I could pull the wiring through and run it to the sensor on the rail, or maybe pull one of the sensors from the back and put it in the rail and just hook the wires up, and then I can get on a dyno here and you can link up online to see what's happening? Also, with the knock sensor thing, if I end up getting the ECU later, could I just hook up everything and get on the dyno here so you can verify it's working too?

No I believe you, I'm just saying that at some point before I bought the turbo I was told that it's efficiency range was 25psi and up, and I think Full Race is who told me that in an email, but that was back in 2010/2011 and I'm sure a lot more has been discovered about this turbo since then.

Wow, we are on the outer edges haha.

Do you mind if I put all this info in my 7670 thread? I never did get a dyno run for people to see what it could do and I think this info could be useful to others.

Not at all. I was actually wanting to do a thread when I had time showing actual turbo speed and PR data. It's something I've never seen on the forums before.

Just looked at intake temp data and that's a contributing factor to the off the map efficiency as well. Ambient temp was around 101 in the shop. Pre-turbo inlet temp was around 110. Charge temp in the manifold was ran up to 140 at 16 psi and 160 at 20 psi. Drop that temp down and turbo efficiency goes up as well as power by quite a bit. Getting some ducting on the IC should help a good little bit.

I'll try moving that MAP reference on the FPR and see what happens. The rear sensor harness is somewhat modular and there is a breakout under the hood if you wanted to relocate a sensor for testing.

Ok. Maybe I'll just post up the dyno results so far and then link to your thread once you start it.

Hmmm, I hadn't thought about that. I noticed in one of the pics the other day that the thermometer said 100+, but I didn't think about it making much of a difference. I had ducting on my old VMIC setup, and I plan to make some for this one too. Although in the winter I plan to block off part of the oil coolers and radiator; my water temps get down to 165F while moving, and I've seen my oil temps get down to 109F while moving. I think I'll replace the oil thermostat, I've checked it and had it installed correctly. Anyway, my point is my air temps should be a good bit lower out here, at least during the winter, but I don't remember what they've been during the summer. But I still plan on doing ducting either way, especially since I'll have the AC condenser in there and operating again. And I'm thinking about running some ducting to the ignition coils too.

Ok sounds good. I'm eager to see if that helps. Ok awesome, I'll just move one of the sensors from the back into the fuel rail then and hook it up to the harness so I can log it, then I'll take it to a dyno so you can remote in and see for yourself.

I noticed you had mentioned pre-turbo temp and UIM temp, do I still need to buy a sensor for post-turbo or did you install one already? I know I'll need to install an EMAP sensor in the turbo manifold.

[lOOkatme]

Does the pulsation matter? and how do you know if the readings are good? The was a thread on rx7club with a guy who had the same problem. he basically changed everything in the system and nothing changed the results.


http://www.rx7club.com/single-turbo-rx- ... 5-1059202/

[speedjunkie]

Does the pulsation matter? and how do you know if the readings are good? The was a thread on rx7club with a guy who had the same problem. he basically changed everything in the system and nothing changed the results.


http://www.rx7club.com/single-turbo-rx- ... 5-1059202/

I believe it's supposed to be a fairly flat line instead of jumping like mine. Apparently it doesn't matter too much because he said it doesn't seem to hurt performance. However, maybe it's smoothed out by the time it hits the fuel rail. I won't know until I swap one of the rear sensors into the rail and hook it up to the ECU. I'll check out that thread. Thanks!

EDIT: Chris posted in that thread haha, and I sent it to him before I saw that he had already seen it.

[Shadowden]

Did Chris build your harness? If so, then he would have put in a larger gauge wire. Otherwise, seems he would try to run the ground straight to battery ground.

[lOOkatme]

I didnt have much time to post last night.

Remember me talking about getting cold air to the intake and running a velocity stack and a large (low pressure drop) air intake filter.

All of this effort is to reduce the pressure ratio of the turbo. Same with feeding cold air into the intake. The whole idea behind running a large filter, velocity stack, and 3" open exhaust is to create the largest pressure differential across the turbo. These mods lower the pressure ratio of the turbo making it more efficient. Remember that your car right now is at sea level, coming up in altitude just makes the turbo work harder, make it suck through a HUGE straw and blow out a HUGE exhaust. little lost work.

Another thing to think about is turbine speed. I think you posted a max turbine speed, but think about how often you are actually at that speed. very little. I don't see that as a big deal.

Remember that driving the car is more about making the set up more fun to drive and for most that means more speed. More speed means higher risk, so anything that can reduce risk (crashing) and increase speed is a huge benefit. having a turbo with a wide powerband makes it easier to drive and will most likely be faster for the stuff we do even if it makes less peak power than another larger turbo. I wouldn't be dissapointed by having XXX WHP. think more about how easy the car is to drive. Hell, I am switching turbos for that very reason and I am literally just swapping to it for a broader powerband, not looking for more WHP. I also want to ditch the external wastegate.

Speed and safety is a function of predictability. The car performs the same every time and behaves in a way that if you are slightly wrong it is forgiving and able to recover easily. Stretched tires, softer rate springs, broad powerband I think is the key to going fast everywhere. I think you basically are setting up your car this way. everything else we do is trying to make the car more reliable. I think your set up is awesome and I am eager to see how it all fits together in the end. Keep in mind that this is all my opinion, and others like stiff spring rates, and more power.

closing statement. One thing that benefits absolutely everything in a cars performance and is somewhat skipped over by many is reducing weight. it helps in every single area of the cars performance and most overlook it. I might start looking at everything on my car and start dropping weight. Add weight to the spots that need it, drop it from where you don't.

[speedjunkie]

Did Chris build your harness? If so, then he would have put in a larger gauge wire. Otherwise, seems he would try to run the ground straight to battery ground.

Yes he did. Larger gauge wire for what? What are you referring to?

I didnt have much time to post last night.

Remember me talking about getting cold air to the intake and running a velocity stack and a large (low pressure drop) air intake filter.

All of this effort is to reduce the pressure ratio of the turbo. Same with feeding cold air into the intake. The whole idea behind running a large filter, velocity stack, and 3" open exhaust is to create the largest pressure differential across the turbo. These mods lower the pressure ratio of the turbo making it more efficient. Remember that your car right now is at sea level, coming up in altitude just makes the turbo work harder, make it suck through a HUGE straw and blow out a HUGE exhaust. little lost work.

Another thing to think about is turbine speed. I think you posted a max turbine speed, but think about how often you are actually at that speed. very little. I don't see that as a big deal.

Remember that driving the car is more about making the set up more fun to drive and for most that means more speed. More speed means higher risk, so anything that can reduce risk (crashing) and increase speed is a huge benefit. having a turbo with a wide powerband makes it easier to drive and will most likely be faster for the stuff we do even if it makes less peak power than another larger turbo. I wouldn't be dissapointed by having XXX WHP. think more about how easy the car is to drive. Hell, I am switching turbos for that very reason and I am literally just swapping to it for a broader powerband, not looking for more WHP. I also want to ditch the external wastegate.

Speed and safety is a function of predictability. The car performs the same every time and behaves in a way that if you are slightly wrong it is forgiving and able to recover easily. Stretched tires, softer rate springs, broad powerband I think is the key to going fast everywhere. I think you basically are setting up your car this way. everything else we do is trying to make the car more reliable. I think your set up is awesome and I am eager to see how it all fits together in the end. Keep in mind that this is all my opinion, and others like stiff spring rates, and more power.

closing statement. One thing that benefits absolutely everything in a cars performance and is somewhat skipped over by many is reducing weight. it helps in every single area of the cars performance and most overlook it. I might start looking at everything on my car and start dropping weight. Add weight to the spots that need it, drop it from where you don't.

Yes and I still plan on making that intake pipe, or at least trying it. I'm a little more limited on space than you are, so I can't go too big with a filter to fit over the stack. But I would like to optimize it if possible and I need to make a new pipe anyway. I'd still also like to go to a 4" downpipe at least, if not the midpipe and catback too.

I don't see the peak turbine speed as a big deal either, I just thought it was cool lol. And as long as I don't run into an overspeed situation, I'm not worried.

I'm not really disappointed by my numbers, it just wasn't as high as I figured it would be considering the new parts that are on there. But I would like to see just what it can do, how high it can get, while still being capable of the nice powerband it has. Even if I drop it down to a lower boost setting in the end. I'm more into the powerband than the numbers. However, I also don't want to get too crazy down low because if my tires just spin, what good is that? AND I'd be suffering top end for it. That's why I've been looking at the 8374. But if I can get these decent numbers and a great powerband out of the smaller 7670, and I don't have to do the work of swapping, I'm cool with that haha. I just want a well balanced car, as good as I can get it.

I'm definitely trying to set my car up that way. And you've done way more suspension tuning research than I have, and it's something I've always wanted to tackle but didn't know how, so I have no problem just copying your setup lol.

Dropping weight is something I definitely have skipped so far, and mostly that is because I'm not building it just for the track, but for comfort on the street as well. I used to love the Sport Compact Car Ultimate Street Car competition and I've tried to move in that direction a bit, making it an all around car and not just track or street. If I lose weight with some of the mods I'm definitely happy about that, but I know I've added some weight back in too. I want to weight it when I'm closer to finished just to see where it is compared to stock.


Alright here is some more chat between me and Chris over the past few days.

I was going to suggest an oil thermostat but you already have one. So, yeah, I'd look at why it's not working correctly. The cooling system is impressive! The big oil coolers are the key I'd guess. That helps water temps big time as well.

Attached a crappy cell pic of the compressor map with data points plotted. I now think more pressure wouldn't be so bad. I'm pretty sure I can setup the ECU to limit turbo speed so that it would automatically stop an overspeed condition at high revs.

I also looked at the fuel pressure data some more and FP1 and FP2 mirror each other. I may be wrong but to me that says what is happening is common to the system and we're probably seeing the same thing up at the rail. I'll move that MAP reference when I get a chance and test it.

Yeah I'll probably pick up another thermostat before winter. The oil coolers definitely help, so much so that I'll either block off part of them or part of the radiator or both, for the winter.

Is there anything this ECU CAN'T do? haha I'd love to do 24psi on ethanol if we can figure out the ignition issue.

I'll move one of the sensors from the rear up to the front to test it out after I get the car back. I'm wondering if those fluctuations are due to the fuel pumps since they're so close to the pumps, and I wonder if it's not dampened more once it gets to the rail. My curiosity is going to get the better of me, I need to figure this out haha.

This is interesting regarding the fuel pulsation issue.

http://www.rx7club.com/single-turbo-rx- ... 5-1059202/

Something I think I forgot to tell you, I was using the fuel pumps to drain the tank before I brought the car to you and they didn't seem like they were pumping enough fuel. But if they're supporting 450ish ethanol, I guess they're working fine. I'm not sure why they seemed inop at the time.

Read that thread. PISTONS final solution was a pump voltage issue. That could be your issue but your wiring is well done and I would ASSume that couldn't be an issue.

I'll have some time tomorrow. I'm going to move the MAP reference around to see if that does anything. Also going to remove the fuel cap to make sure the tank is being vented properly. If the vent is clogged, I can see that causing the issue. Also going to crank up the sample rate in the log. Vicoor's post showing sample rate influence was interesting. Some channels on the Syvecs can be logged at up to 1000hz, so we'll crank it up and see what we get. Right now fuel pressure is probably set at 5 or 10hz.

Also, re ECU exchange. If we need to do that after you pick up the car, it will be a simple swap. All the firmware and software can be loaded on to the new box and you'll just need to plug it in and go.

Yeah after I sent it to you I noticed that you had posted in there last year already. I would assume wiring is not my issue also, but who knows. I didn't read through the whole thread because it was late when I sent it.

OK sounds good! I look forward to hearing the results.

OK sounds good. I imagine they'll send the ECU straight to you and you could put the map on there. I'm not too concerned about that. Probably more-so on how long it will be until it's ready and hoping it's before I deploy again.

[lOOkatme]

The points at the same boost pressure when run at higher altitude will move the graph up some, and if the car on the street puts more load on the engine than the dyno, the points will all move left.

so you might be hitting max efficiency of the turbo at 20PSI when you run it on the street and at high altitude. Hence my suggestion of running low 20ish or so PSI as being the most efficient range for the turbo.

[speedjunkie]

The points at the same boost pressure when run at higher altitude will move the graph up some, and if the car on the street puts more load on the engine than the dyno, the points will all move left.

so you might be hitting max efficiency of the turbo at 20PSI when you run it on the street and at high altitude. Hence my suggestion of running low 20ish or so PSI as being the most efficient range for the turbo.

Well running at 20psi down there should be about 24psi up here anyway, right? So it might be right where I want it, and maybe I was running closer to 30 actual psi before lol.

By the way, here is a guy that has 10.5" wheels with the Dunlop Direzza tires I want in the size I want. It might stretch a bit too far for me, 1/2" on each side might be a bit much. Maybe not though.
http://www.rx7club.com/suspension-wheel ... st11958858

[lOOkatme]

are you thinking about going 11.5" wheels? or 11" wheels?

the Zii are 10.7" tread width. run them on a 11" wheels. slight stretch. perfect. They will fit on a 11.5" wheel though.

[speedjunkie]

are you thinking about going 11.5" wheels? or 11" wheels?

the Zii are 10.7" tread width. run them on a 11" wheels. slight stretch. perfect. They will fit on a 11.5" wheel though.

I'm still planning on trying to do 11.5", I was talking about 1/2" stretch on each side of the wheel, not each side of the car. Either way I'm lost until I do my brakes.

[lOOkatme]

What about running a 295 30 18 tires all around on 11.5" wheels.

You can also not duct the brakes and run aggressive brake pads and go all out on the tires and wheels. Perhaps there are brake ducts that don't need the duct, but route cold air from underneath the car? If you find some let me know, I might be interested in them as well but I don't want to run any ducting hose, just a duct " grabber" of air.

[lOOkatme]

This guy is doing something of what I would do. route air to blow in the general area of the brakes and let the brakes suck it up as they act like an air pump.


http://www.rx8club.com/series-i-do-your ... use-83801/