Arca's Time Attack Build Thread (13b-REW Swap)
#201
The S1 is lighter than I originally reported. Recently shipped one @ 77 lbs including some heavy packing/boxing. Theres a picture of an S2 trans weighing 95ish scaled on the forum.
Your weight doesn't take into account how you intend to handle the trans/PPF/diff support issue.
Your weight doesn't take into account how you intend to handle the trans/PPF/diff support issue.
Even if the whole swap added weight I wouldn't really care. Since PT classing has a minimum weight, I can remove that weight from somewhere higher in the car and even though total weight wouldn't change, the CG would be lower which is beneficial.
I think even if I couldn't find somewhere else to take out weight if the trans swap was heavier, the benefits of a close ratio dog box would achieve lower lap times even with increased weight. Reliability is the main point anyways. Like I said before, all depends on whether or not the stock unit can handle it, which I doubt.
#204
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and non-PPF transmissions are not designed for that kind of loading either, but I think a few have been converted in the past, seems like maybe the Jerico racing trans as I recall
just saw that Par Engineering now has replacement dog & synchro gear sets for the S1 RX8 AZ6 6-spd trans case
not cheap, but a direct swap & bolt-in
just saw that Par Engineering now has replacement dog & synchro gear sets for the S1 RX8 AZ6 6-spd trans case
not cheap, but a direct swap & bolt-in
#210
Decided that I can't wait for the dry sump pan anymore since it's taking longer than expected, I will be sourcing a stock oil pan and just build everything and put the dry sump stuff on later.
Also a friend of mine is going to Willow Springs next weekend and he made an offer to drop by any of the places he is a vendor for and hand deliver body pieces to save on shipping. That's a savings of around $150 bucks on top of the good deal he was already giving me so I ordered one of these.
It will give me more space for the v-mount. I don't expect fitment to be very good but it's cheap, and if I can clamp it to the car, it doesn't fall off, and it looks good from 50 feet away then I'll be fine with that.
Also a friend of mine is going to Willow Springs next weekend and he made an offer to drop by any of the places he is a vendor for and hand deliver body pieces to save on shipping. That's a savings of around $150 bucks on top of the good deal he was already giving me so I ordered one of these.
It will give me more space for the v-mount. I don't expect fitment to be very good but it's cheap, and if I can clamp it to the car, it doesn't fall off, and it looks good from 50 feet away then I'll be fine with that.
#212
Decided that I can't wait for the dry sump pan anymore since it's taking longer than expected, I will be sourcing a stock oil pan and just build everything and put the dry sump stuff on later. Also a friend of mine is going to Willow Springs next weekend and he made an offer to drop by any of the places he is a vendor for and hand deliver body pieces to save on shipping. That's a savings of around $150 bucks on top of the good deal he was already giving me so I ordered one of these. It will give me more space for the v-mount. I don't expect fitment to be very good but it's cheap, and if I can clamp it to the car, it doesn't fall off, and it looks good from 50 feet away then I'll be fine with that.
I did spend a few hrs cutting n filing etc but it does fit pretty good. My only complaint is the recess area for indicators. It's pretty bad there. It needs professional help haha. Saying that, if u can live without those indicators I think it would be easier to fill it in, smooth it off and just drill it for mounting bolt. I had to cut n shape it along the top edge above the indicator too, to form the the cars shape.
#214
I have that bumper.
I did spend a few hrs cutting n filing etc but it does fit pretty good. My only complaint is the recess area for indicators. It's pretty bad there. It needs professional help haha. Saying that, if u can live without those indicators I think it would be easier to fill it in, smooth it off and just drill it for mounting bolt. I had to cut n shape it along the top edge above the indicator too, to form the the cars shape.
I did spend a few hrs cutting n filing etc but it does fit pretty good. My only complaint is the recess area for indicators. It's pretty bad there. It needs professional help haha. Saying that, if u can live without those indicators I think it would be easier to fill it in, smooth it off and just drill it for mounting bolt. I had to cut n shape it along the top edge above the indicator too, to form the the cars shape.
Yep. It's getting even more cut up for the V-mount intercooler exhaust and I'm adding another row of louvers next to the existing ones that are running up the hood.
#215
Well, I changed my mind on the turbo after getting several opinions of guys that have experience running REW's on track...
Going larger will bring down manifold pressures and EGT, I don't mind taking a small hit in spool and response in order to make life easier for the engine.
Not my picture but feel free to guess what it is.
Going larger will bring down manifold pressures and EGT, I don't mind taking a small hit in spool and response in order to make life easier for the engine.
Not my picture but feel free to guess what it is.
#219
Nope.
It's an EFR 9180.
I'm expecting the EGT will be about 200 to 300 degrees F cooler. It will also help me with power under the curve using boost by RPM to achieve a completely flat horsepower curve, so at every RPM between 4500 and 8000 I can be making my maximum allowable horsepower in class.
Some people might be worried about spool and boost threshold on such a large turbo but thanks to the engineering that went into the EFR turbos, I should be able to make about 1bar by 4000RPM.
It's an EFR 9180.
I'm expecting the EGT will be about 200 to 300 degrees F cooler. It will also help me with power under the curve using boost by RPM to achieve a completely flat horsepower curve, so at every RPM between 4500 and 8000 I can be making my maximum allowable horsepower in class.
Some people might be worried about spool and boost threshold on such a large turbo but thanks to the engineering that went into the EFR turbos, I should be able to make about 1bar by 4000RPM.
Last edited by Arca_ex; 07-15-2014 at 01:52 PM.
#220
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Nope.
It's an EFR 9180.
I'm expecting the EGT will be about 200 to 300 degrees F cooler. It will also help me with power under the curve using boost by RPM to achieve a completely flat horsepower curve, so at every RPM between 4500 and 8000 I can be making my maximum allowable horsepower in class.
Some people might be worried about spool and boost threshold on such a large turbo but thanks to the engineering that went into the EFR turbos, I should be able to make about 1bar by 4000RPM.
It's an EFR 9180.
I'm expecting the EGT will be about 200 to 300 degrees F cooler. It will also help me with power under the curve using boost by RPM to achieve a completely flat horsepower curve, so at every RPM between 4500 and 8000 I can be making my maximum allowable horsepower in class.
Some people might be worried about spool and boost threshold on such a large turbo but thanks to the engineering that went into the EFR turbos, I should be able to make about 1bar by 4000RPM.
450 RWHP @ 4500 rpm???
unless you lowered the power limit from what I previously recll then I haven't seen anything close to that power/rpm point with said turbo on a 2-rotor
#221
The power levels for other classes will be able to make the max power figure from 4500 no problem.
Here's a small sheet I worked up for all the different configurations of the following factors, calculated with a minimum weight of 2800lbs.
DOT approved tire 275mm wide (e.g. Hoosier R6, Hoosier A6, Maxxis RC1, Nitto NT01 etc.)
Non-DOT 10.5" wide (Hoosier Slick, Yokohama A008, Michelin Slick)
Then Dog Engagement vs. Synchromesh is a different power modification factor as well.
These are absolute maximum numbers and I will likely stay about 15 to 20RWHP under any limit I choose in the event I have to do compliance testing on a Dyno.
Only thing is that I might not be able to make low enough HP for TT3. This depends on whether or not 7PSI springs in the wastegates will blow open in high boost operation. I won't know until it's on the dyno. If I have to switch to stiffer springs, I would likely make too much power even on wastegate pressure. I'm not really too concerned about this because TT3 in my NASA region is dog eat dog, and sometimes their times are the fastest overall times of the day... the top three drivers in that class would likely mop the floor with me haha.
I've put in bold which setups I would prefer to use for each class. You can choose whatever class you would like to participate in at the beginning of the event, so if it looks like the odds of winning tire contingency is better in a certain class, I can be flexible.
Unlimited
500+ Non-DOT w/ Dog Box
TT1
555 DOT
539 DOT w/ Dog Box
491 Non-DOT
475 Non-DOT w/ Dog Box
TT2
373 DOT
363 DOT w/ Dog Box
341 Non-DOT
333 Non-DOT w/ Dog Box
TT3
314 DOT
307 DOT w/ Dog Box
291 Non-DOT
285 Non-DOT w/ Dog Box
Last edited by Arca_ex; 07-15-2014 at 05:44 PM.
#222
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I haven't seen anything come close to that revised power/rpm point either. I don't see how you can get the boost that high at that low of an RPM with that particular turbo on a 13B, but maybe nobody has pushed it there yet. It seems to me that for that power/rpm range you're better off dropping down a size, especially for those lower classes. On E85 your EGT shouldn't be that big of a concern
#223
Preferably I'd like to stay below 1700F for EGT's. Even on E85 it's tough.
Here's a local car that got tuned at the same shop that I'm going to. He's using a Borg Warner S366 which has nearly the same compressor and turbine wheel dimensions as the EFR 9180. The 9180 has better wheel design, wheel weight, flow capacity, spool, and it is ball bearing instead of journal bearing. Also I'll be using a 1.05a/r turbine housing, he had a 1.10a/r, both T4 divided.
He made 450WHP at about 5200RPM at 26 PSI.
It's going to be really close, we'll just have to see when it's done.
His setup:
E85
Street ported 13b-REW
2x ID1000 Primary
4x ID2000 Secondary
AEM Standalone
Borg Warner S366 with T4 1.10 Divided Turbine Housing
Dual 40mm external wastegate
3.5" downpipe and exhaust
Also note he was previously on a GT4088 with 1.06a/r housing, EGT's were mid 1800's, and now with the new setup and tune he's running just about 1700. A 35r size turbo would most likely be above 1850F if ran at the edge of what it can do.
Here's a local car that got tuned at the same shop that I'm going to. He's using a Borg Warner S366 which has nearly the same compressor and turbine wheel dimensions as the EFR 9180. The 9180 has better wheel design, wheel weight, flow capacity, spool, and it is ball bearing instead of journal bearing. Also I'll be using a 1.05a/r turbine housing, he had a 1.10a/r, both T4 divided.
He made 450WHP at about 5200RPM at 26 PSI.
It's going to be really close, we'll just have to see when it's done.
His setup:
E85
Street ported 13b-REW
2x ID1000 Primary
4x ID2000 Secondary
AEM Standalone
Borg Warner S366 with T4 1.10 Divided Turbine Housing
Dual 40mm external wastegate
3.5" downpipe and exhaust
Also note he was previously on a GT4088 with 1.06a/r housing, EGT's were mid 1800's, and now with the new setup and tune he's running just about 1700. A 35r size turbo would most likely be above 1850F if ran at the edge of what it can do.
Last edited by Arca_ex; 07-15-2014 at 06:29 PM.
#224
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the S366 flow map is similar to the EFR 8374, what I'm saying is that as good as the EFR 9180 response is for it's size you can still make the same power with even a whole lot more response
whole bunch of info on this with 13B on various forums, is your sponsor pushing you towards the EFR 9180? Seems kind of odd considering ...
whole bunch of info on this with 13B on various forums, is your sponsor pushing you towards the EFR 9180? Seems kind of odd considering ...
Originally Posted on RX7Club by Full-Race Geoff
absolutely - yes. The EFR's internal wg is very large and has a veryyyy high flow rate for an iwg... I have not seen any single instance of boost creep with these turbos on any engine to date
For your <500hp target this would be an excellent match as long as you dont plan to turn the boost up so high that it maxxes out the 0.92 a/r (around ~520-530whp and 26-28psi). Attached is a photo from one of our customers that's planning to try this setup out
absolutely - yes. The EFR's internal wg is very large and has a veryyyy high flow rate for an iwg... I have not seen any single instance of boost creep with these turbos on any engine to date
For your <500hp target this would be an excellent match as long as you dont plan to turn the boost up so high that it maxxes out the 0.92 a/r (around ~520-530whp and 26-28psi). Attached is a photo from one of our customers that's planning to try this setup out
Originally Posted by Turblown on RX7Club
We hoped on another dyno again yesterday with Shawn's car. Voltage was mainly fixed, but the fuel pump still ran dry past 5500rpms( down to 40psi , with a base fuel pressure of 50psi and 25 to 27psi).
With the voltage from moved from 11.5 to 12.7 to 13.1 volts( still not not perfect, but better) it made 516rwhp and 426rwtq by 5500rpms @ 25psi. The fuel pump's second stage is now going to be turned on and a bigger alternator put on. I have a feeling its going to be near 600rwhp all said and done. I intend to turn up the boost even more too.
I finally got to ride in the car, and this is by far the best 2 rotor turbo system I have ever experienced. The boost response and dyno charts don't lie, this car is an absolute animal, and feels like a highly modified stock twin R35 GTR.
With the voltage from moved from 11.5 to 12.7 to 13.1 volts( still not not perfect, but better) it made 516rwhp and 426rwtq by 5500rpms @ 25psi. The fuel pump's second stage is now going to be turned on and a bigger alternator put on. I have a feeling its going to be near 600rwhp all said and done. I intend to turn up the boost even more too.
I finally got to ride in the car, and this is by far the best 2 rotor turbo system I have ever experienced. The boost response and dyno charts don't lie, this car is an absolute animal, and feels like a highly modified stock twin R35 GTR.
#225
the S366 flow map is similar to the EFR 8374, what I'm saying is that as good as the EFR 9180 response is for it's size you can still make the same power with even a whole lot more response
whole bunch of info on this with 13B on various forums, is your sponsor pushing you towards the EFR 9180? Seems kind of odd considering ...
whole bunch of info on this with 13B on various forums, is your sponsor pushing you towards the EFR 9180? Seems kind of odd considering ...
My application is kind of weird with the whole boost by RPM thing. A 500HP peak HP goal is just begging for the 8374, but if I want to be able to make big power down lower, it kind of makes things a little harder to decide.
The 8374 is definitely an awesome turbo and extremely responsive.
The things that kind of have me leaning towards the 9180 is lower exhaust manifold pressure, lower EGT, lower intake air temperature, lower intake manifold pressure, and more power under the curve for the flat HP map.
The upsides of the 8374 are definitely transient throttle response and lower boost threshold RPM.
Now going back to the power under the curve thing, the main class I will be competing in at NASA is TT1, so at NASA events, that is the priority. The bigger priority though is Global Time Attack, and there are no power caps there. I don't know how long I will run this car at NASA. I really want to do small bore race group with a Miata some day, and this car would just be for time attack events, reducing its use to maybe 3 events per year and just using NASA to do shakedown testing as needed.
Anyways. In that post they hit 426 ft-lbs of torque at 27PSI, the previous dyno graph shows that his torque curve is pretty much flat, so if I wanted to run a boost map with a 450WHP flat horsepower curve that spiked at 27PSI, I wouldn't reach 450WHP output until 5550RPM and above, where as the 9180 could potentially be making that number 550RPM sooner.
The other thing with running higher boost and having higher exhaust manifold pressure is that I have to run stiffer wastegate springs to prevent the gates from blowing open so who knows what the lowest output of each setup will be. Most likely a wash since I'll have to run stiffer springs with the 8374, so I can't really say if one setup would help with fitting into lower classes better than the other. You're definitely right that the 8374 will perform better at those lower power numbers but it's just not as high on the priority list for me.
I don't mind sacrificing a little bit of response in order to make that 450WHP plateau a little wider along with making life a little easier for the engine and having more headroom for Global Time Attack.
At least that's my reasoning... lol.
Or maybe I'm just a ricer and want to brag about having the biggest EFR while I'm hard parking at car shows.
Last edited by Arca_ex; 07-15-2014 at 09:29 PM.