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Man, that thing is being run HARD. That's a ton of boost to cram into this engine on pump gas + w/m.
Definitely look into your boost control strategy and ignition timing as it should be hitting your boost target quite a bit sooner, as well as power should be higher below 3000 RPM. 508whp, cool!
Man, that thing is being run HARD. That's a ton of boost to cram into this engine on pump gas + w/m.
Definitely look into your boost control strategy and ignition timing as it should be hitting your boost target quite a bit sooner, as well as power should be higher below 3000 RPM. 508whp, cool!
im guessing he didnt get go WOT below 4k rpm.. i personally like to go as low as possible, start at 1.5k or 2k and but i make power there, some don't
Well spotted guys.
Without writing an essay.
I had a 363sxe which had loads of play in it so I upgraded to a 64mm turbo. Went to install it and it would not fit even though they share the same exhaust wheel size.
Measured the 363 exhaust wheel and it was 3mm smaller where it had been hitting the housing, this had fused onto the housing and made it smaller so I hand ported it whilst it was still on the car. Why? Because I had welded the down pipe to said housing because I hate marmon flanges.
I did try to buy a new one but BW said 8 weeks and I had Trackdays and such booked.
I don’t think it’s hurting the top end any so can live with it for meantime. Itching to half bridge and 9280 over the winter anyway.
first off congrats on your successful session. also for your ECU and SXE 64 choices.
i remain very interested in IATs. simply put, high IATs break rotary engines and it is my opinion that due to the type of sensor we use to monitor them that we may be generating much higher IATs than we suspect.
your data is a perfect example.
both the data and the slope look like you are playing catch-up. the question is, how far behind are you?
at 26 psi the air coming out of your SX-E is above 325 F. i know this because i use a type K thermocouple rather than a thermistor. a thermocouple generates four readings per second accurate to plus or minus .4 of one per cent which would about one degree F at 120 F. i have one in the 6 inch tube between my turbo and my intercooler so i know you are looking easily at 325+ F at 26 psi. i have another in the stock UIM FD location.
you post a reading of 84 F at 5337 and an eventual high reading (111) at the end of your run around 8000.
the dynamic rise isn't linear.
on a 509 hp run w my SX-E 62 1.0 i posted my high IAT reading 752 rpm after 100% TP.
on a 575 hp run w my EFR 9180 it took 1111 rpm. (both in third gear, if they were in fourth it would have been shorter, also diff boost control settings).
my IATs declined to redline as i use 100% meth as AI but my point is your readings are just a linear stair step and are therefore suspect.
given you are on stock ports and at 26 psi i suspect there must be quite a bit of restriction which tends to work against lower IATs. for instance, the stock primary port is tiny, really really tiny. any serious port work focuses on fixing the primary which would remove a significant flow restriction and tend to lower IAT. if you plan to run stock ports going forward i recommend you switch to 900/1000 CC of 100% methanol and pick up an air themocouple.
"The Sensor Connection" P/N EGT-AP-072-0181-55-N $53 please double check part number... also feel free to buy it elsewhere if you wish.
1000CC's of AI, can the stock ignition system with just an HKS twin ignition power boost actually fire that amount of AI up without missfiring Howard?
Asking for myself*
Howard said he's running pure meth, from what I recall doing that will cause pre-detonation for anything resembling a "moderate" amount (which is why he was (is?) constantly rebuilding his engines).
The way around that is to either push a LOT of meth or just do a more reasonable mix of 50/50 water/meth. Doing 50/50 trades a minor amount of IAT cooling for far more safety and stability.
Thanks Howard. Thanks to you Ryan, Skeese and a few others on this forum I was able to build and tune this engine myself.
Having re-read what I said I bet you are all thinking I’m nuts. Melting an inconel turbine wheel.
What I forgot to say was that I had been playing around with antilag on an adaptronic modular and had set the parameters wrong so it was stuck on. I was driving for about 20 minutes and just thought the ecu was playing up on me again, it wasn’t until I tried boosting that I realised it was on. Ignition was retarded 35 degrees!
Will look into that sensor, at the moment I’m using the plug and play LMS EFI one. It does have a couple of seconds delay which is to be expected. I inject 250cc into the turbo and 500cc at the elbow.
IGN1a’s FTW
Thanks Howard. Thanks to you Ryan, Skeese and a few others on this forum I was able to build and tune this engine myself.
Having re-read what I said I bet you are all thinking I’m nuts. Melting an inconel turbine wheel.
What I forgot to say was that I had been playing around with antilag on an adaptronic modular and had set the parameters wrong so it was stuck on. I was driving for about 20 minutes and just thought the ecu was playing up on me again, it wasn’t until I tried boosting that I realised it was on. Ignition was retarded 35 degrees!
Will look into that sensor, at the moment I’m using the plug and play LMS EFI one. It does have a couple of seconds delay which is to be expected. I inject 250cc into the turbo and 500cc at the elbow.
IGN1a’s FTW
"I had Trackdays and such booked" "Itching to half bridge and 9280"
this post is going on the assumption that "Trackdays" refers to road courses, not a drag strip.
as a starter here's something i posted in the 3rd Gen Section:
The September Road and Track interview of Tadge Juechter / Chief Engineer 2020 Chevrolet Mid Engine Corvette was highly relevant to the FD.
the first question:
WHY Mid Engine?
"Biggest was the limit of performance. We knew we were in trouble bringing out the 638 hp (542rwhp) C6 ZR71 and we had a hell of a time beating the 505 hp (429 rwhp) Z06 0 to 60. It was only because of the Michelin tires that we were able to... We couldn't hook it up. So that was kind of the start of it. Fifty-fifty weight distribution is great when your not power limited. That's why race cars evolved with the engine in the back. You really want more like 40/60 so you can get the power down."
With 215 rwhp our 50/50 FDs, as well as the Miata, have no traction issues. Unfortunately it is all too easy to add power and a 350 rwhp single turbo setup is considered conservative, 400 still not crazy, 500 is sporty and 600 is within reach on pump gas and meth AI with pretty good durability.
yet Tadge is saying that 429 rwhp is about the limit for the 3130 pound C6. at 50/50. The 638 hp version ended up with 335/25 tires on a 20 by 12 inch rear wheel. weight was 3353 with a 51/49 distribution so the all important rear weight was 1643 pounds.
the mid engine Corvette weighs 3366 dry (as per November Hot Rod Magazine) so call it 3400 curb. no distribution numbers but mid engine cars generally range from 56.5 to 59.3 (as per August Car and Driver) so let's use the middle:
3400 X .579 = 1969 rear weight... so a primary reason for the mid engine Corvette was to gain 350 pounds of rear weight.
FD 2862 X .5 = 1431
recap:
2013 Z06 505 flywheel/429 rwhp, 3199 curb weight, 1600 rear weight, 335/25/20. 3.73 pounds rear weight per one rwhp
2013 Z06 ZR1 638 flywheel/542 rwhp, 3353 curb weight, 1643 rear weight, 335/25/20....3.03 pounds rear weight per one rwhp
255 flywheel/217 rwhp, 2862 curb weight, 1431 rear weight, 225/50/16... 6.59 pounds rear weight per one rwhp
let's solve for rwhp per rear weight of the 505 Z06:
1431/3.73 = 384 rwhp
Chevrolet had to upsize the rear tires on the 638 hp C6 to barely "hell of a time" beat the 505 hp Z06 which is the equivalent of a 384 rwhp FD!
obviously there are many qualifiers here but there is some truth also. ask most really experienced track (we are talking road courses) guys and they will tell you that they really don't need much above 400 rwhp to get the most out of the FD chassis. an awful lot of additional hp sort of goes up in tire smoke and also becomes extremely difficult to manage. there is nothing wrong w additional hp and it certainly results in faster times in the quarter mile etc.
as you get up above 500 rwhp, given our rear weight it does become easier to go sideways or lose traction. of course you can engineer around almost everything but for many of us in this web based world where everyone wants 600 rw (bigger is better?) perhaps, given our 1430 rear weight a bit of judiciousness might be in order as we contemplate our FD mods.
my background is road racing and i have always considered front weight to be evil, which is another way of saying rear weight is good. i have around 52% rear bias. i do recall talking w a 630 rwhp 20B FD owner at the Rotary Revolution. he had his car running well w a smallish turbo to limit the power but said he had to be very careful as even at 140 mph he could make his car go sideways if he wasn't careful.
having power is one thing, being able to efficiently use it may be another."
you currently possess a 600 rotary rwhp turbo... it is a gem and is a complete mismatch for your stock ports.it can be ordered with the 76 or 80 mm hotside wheel. your SX-E 63 also can be ordered with either wheel. if your 63 and 64 turbos have the 76 wheel they use the same (177209 for 1.0 AR), (177208 for .91 AR) hotside housings.
"he hit WOT at ~2.3/2.4K rpms... a bit laggy boost response for a SXE364"
something else is going on as to the lag, it isn't the turbo.
as to the weirdish Marmon flange on the SX-E line... various companies make very nice adapters which are a simple task to add to your downpipe. while the flange O D is 4.21 inches the port coming out of the hotside is 3 inches as is the I D of the adapter.
you mention a 9280 and a half bridge... first question is: what do you plan to do with your car? if it is road racing you will be going from a major mismatch (600 hp turbo, stock ports) to another major mismatch (bridge port & 800+ rotary hp turbo do not mix with road racing)
if you want to go fast on a road course w an FD you need linear controllable power. referencing the article, Corvette realized that around 500 flywheel power they needed more rear weight and they switched to mid engine to gain 350 pounds. FD road racing IS about hooking up the driving/rear wheels and the 425 rwhp area is about it as far as lap times with the typical 10 inch rear wheel and rubber.
of course if you are drag racing you can ignore the above.
looking into 2020 there are lots of options for you. assuming you are looking for a dual purpose aggressive street and road course setup i would happily keep your turbo, rebuild your motor w really nice race ports, run gasoline and 630 CC of water meth. i personally prefer 100% meth as AI but it isn't necessary for road racing. i suggested 100% meth to you for your current setup because of the restriction from your stock ports and the attendant high IATs.
for those interested in 100% meth, i recommend an M15 nozzle (945 CC) if you are around 500 to 600 rw. a max delivery of 100% meth should be 25% of total fuel by volume. i have had one engine problem running meth which was a backfire, probably caused by pre-ignition. it took out my primary diffusers and they went thru the engine. i lost compression. after disassembling the motor i found some of the melted diffuser had attached itself to the crown of my apex seals pushing them back against the spring. i removed the melted plastic from the seals and re-assembled the motor sans diffusers. the reason for the backfire is probably that i was running over 3000 CC of meth at the time. i am back to 945 and have never had a problem. here's a recent 575 rwhp run on 93 pump and meth. my knock scale is 0 to 350 and knock was 35. the third scale is IAT, 4th is AI pressure and 5th is knock.
"1000CC's of AI, can the stock ignition system with just an HKS twin ignition power boost actually fire that amount of AI up without missfiring "
misfires relate to combustion chamber pressure mostly and the general thinking is the stock (20+ year old) coils are good to around 400 rwhp. given that is lots of power per displacement, not bad... but really an item that begs for replacement, especially now that the wonderful IGN-1A coils are available. of course a richer AFR causes further challenges as does water since it puts out fires. often misfires (as well as modest knock) are not discernible from the driver's seat. you need to check your dyno power plot at Zero Smoothing. misfires can often be band-aid cured by tightening the .023 gap.
for more on the subject see the Tuning Ignition Section of my site:
I have the 76mm hot side.
I have attached a graph of another Fd that ran 20minutes before my run.
He has a Streetport and is running an SXE 363 at 16psi on water but with the 80mm hot side.
Different tuner/ builder on an Apexi.
thanks for the two dyno plots, it is always fun to take a closer look:
i have an excel spreadsheet with 80 single turbo power plots at 6 RPM points, from 5000 to 7500.
using the red line which i assume is rw power...
the unported motor with the SX-E 64 76 makes a total of 2806 hp placing it at #67 of 80 while the ported motor at 16 psi makes 2264 and slots in at #21.
this just shows that boost is #1 as to power.
OTOH, there is something to be said for efficiency:
the motor running at 26 psi benefited from 32.5% more boost but made only 14% more power if using the max single point reading amongst my 6 postings.
if we use the total of the 6 readings the 26 psi motor made 24% more total power.
in order to compare pressures we need to add 14.7 to the gauge pressure so:
16 + 14.7 = 30.7
26 + 14.7 = 40.7
40.7 / 30.7 = 1.325 or 32.5% more pressure.
a significant amount of flow was lost by the 26 psi motor probably due to the stock ports although there could be loads of other factors at work.
both runs were pretty good considering the factors.
Update.
Ryan was kind enough to have a play with my map and he has done me proud!!
I have attached before and after comparisons at various engine speeds.
I am now on a quest to get this turbo spooling as early as possible.
It was raining as I was testing the new map so had to get out of it early.
Update.
Ryan was kind enough to have a play with my map and he has done me proud!!
I have attached before and after comparisons at various engine speeds.
I am now on a quest to get this turbo spooling as early as possible.
It was raining as I was testing the new map so had to get out of it early.
Can I put that on my resume?
Again, this is without touching transient fueling, ignition timing, etc. There's still a LOT left to this setup.
Those images show it that it is taking longer to get to the same rpm even though it is making more boost at a given rpm
Can you clearly label before and after?
So in the 4000rpm comparison
One version takes 14 seconds from WOT at just under 2000rpm to achieve full boost
In the other version it takes 7 seconds from WOT at just over 2000rpm to achieve full boost?
Even though 14 seconds shows more boost at that rpm looks like the 7 second version is a faster car?
The first run was on a dyno and the second on the road.
I will go out after work today and log 2 runs, first with my old map and second with Ryan’s update.
Should give a clearer picture.
The car has never been mapped on the dyno it’s just me road tuning it and I am learning as I go l, so all input is welcomed.
The important thing is that you don't drive your car on a dyno... Some do, but they live in a fantasy land. Usually you'll have more load on the road + aerodynamics to deal with. Can't wait to see the A vs. B.
The important thing is that you don't drive your car on a dyno... Some do, but they live in a fantasy land. Usually you'll have more load on the road + aerodynamics to deal with. Can't wait to see the A vs. B.
When doing back to back testing it negates the test if the variables are different? Or do you think otherwise?
