When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
as you can see on my dynograph, the power curve ends very early. Much earlier than I thought it would with this fat turbo.
My question is: is it normal or should I look into my tuning?
My exhaust is not restrictive as it 3.5" wide and going out directly through the hood. I had no fuel issue, not pressure loss and I kept 10.5 AFR all along the rpm range.
My setup is as follow:
S362sxe with 0.91 A/R turbine
1000cc bosch motorsport primaries
ID2000 secondaries
gleaseman exhaust manifold
Haltech PS1000
4x IGN 1A coils
4x race NGK plus, heat range:10
98 octane fuel (europe)
homemade V-mount
450lph walbro fuel pump
large streetport from Pineapple Racing
boost pressure was 1.6 bar (about 23psi)
should I look into the ignition timing?
the power shown is at the crank, and the torque (on the right) is in newton meters.
Thanks for your time?
Last edited by Jrm1005; 10-10-17 at 03:12 PM.
Reason: mistake in the exhaust size
Are you running solenoid boost control through the haltech? Does boost stay at target in the top end? If it is just mechanical it will fall off as EMP rises and pushes the gates open. Otherwise would asume it needs a bit more advance in the top end although you are probably approaching choke flow on that compressor too.
What do you mean by OP power? And no, this is not whp but power at the crank.
OP = original poster
So assume 500 whp @ 23 psi. Still sounds decent considering we don't know the dyno. You have to take into account that a rotary will not make the same power on a turbo that a piston engine will.
So being that this is roughly equivalent to an EFR 8374 in size, that's about as much power as I'd expect. The Turbine Housing is your choke point and I bet if you monitored MAP vs. EMAP, you'd see that. Sadly, Borg Warner doesn't offer a larger A/R turbine housing than the 1.00, but realistically, you'd want 1.15-1.25 A/R for this setup to really wake up on the top end.
Cheers, and if you do end up ordering, just reference me as Ryan H. and I'm sure we can do something to help you out.
i'm going to say its because of your .91 turbine housing, your turbo is running out of its efficiency range in the higher RPM's. like mentioned above, go with at least a 1.00 for a longer powerband.
assuming no ignition breakup, and it would have to be noticeable considering the magnitude of your problem, flow is the issue.
there are numerous "Pineapple" ports but if they are properly executed the center of the torque curve (which is max flow into the engine) is between 6200 and 6450.
the center of your torque curve is 5600, low by 600 to 850 RPM. (since your curve isn't symmetrical i used the shoulders at 500N.m to find the center)
a proper torque decline curve from peak to 8000 RPM is approx 17%.
yours drops from 676 to 250! that's 68%.
i can assure you that the BW .91 is not the problem. BW didn't engineer a totally misfit hotside for their masterpiece SXE 62. does the 91 flow less than the 1.0? of course but not to the point of stopping the 570 rotary hp compressor in its tracks.
i would look elsewhere noting that the 50 MM exhaust port has 3.04 square inches of area.
as you know our engines are air pumps.
restrict the incoming air with a small filter and less flow.
restrict the outgoing air (exhaust) with small area and less flow.
build it right and you have minimal restriction at either end.
exhaust restriction is easy to measure...
tap into your turbo manifold, connect to a 0-150 pressure sensor w stainless steel brakeline.
here's the data from my design turbo manifold...
the logger shows i have more boost than backpressure up to 6107 RPM.
after crossover on this run i have only 27% more backpressure than boost.
excess backpressure not only drains power from driving the turbo but increases EGTs and adds heat back into the next intake stroke by virtue of overlap.
simply put you want all the heat out of the motor driving the turbo. to the extent you have backpressure you are losing the battle.
Last edited by Howard Coleman; 09-17-17 at 10:52 AM.
Are you running solenoid boost control through the haltech? Does boost stay at target in the top end? If it is just mechanical it will fall off as EMP rises and pushes the gates open. Otherwise would asume it needs a bit more advance in the top end although you are probably approaching choke flow on that compressor too.
I wasn't using the boost solenoid but I had the 1.6bars until the end of the curve.
Originally Posted by SirLaughsALot
Sounds overly rich. Hug closer to 11.5-11.0 and see what happens (creep up slowly and see what happens). Timing could be off too.
I'd also consider a 1.00 A/R Turbine Housing from my website, here:
So being that this is roughly equivalent to an EFR 8374 in size, that's about as much power as I'd expect. The Turbine Housing is your choke point and I bet if you monitored MAP vs. EMAP, you'd see that. Sadly, Borg Warner doesn't offer a larger A/R turbine housing than the 1.00, but realistically, you'd want 1.15-1.25 A/R for this setup to really wake up on the top end.
Cheers, and if you do end up ordering, just reference me as Ryan H. and I'm sure we can do something to help you out.
Thank you for your offer but the Borg Warner parts are a lot cheaper in Europe than USA, as are the shipping costs!
Originally Posted by Howard Coleman CPR
assuming no ignition breakup, and it would have to be noticeable considering the magnitude of your problem, flow is the issue.
there are numerous "Pineapple" ports but if they are properly executed the center of the torque curve (which is max flow into the engine) is between 6200 and 6450.
the center of your torque curve is 5600, low by 600 to 850 RPM. (since your curve isn't symmetrical i used the shoulders at 500N.m to find the center)
a proper torque decline curve from peak to 8000 RPM is approx 17%.
yours drops from 676 to 250! that's 68%.
i can assure you that the BW .91 is not the problem. BW didn't engineer a totally misfit hotside for their masterpiece SXE 62. does the 91 flow less than the 1.0? of course but not to the point of stopping the 570 rotary hp compressor in its tracks.
i would look elsewhere noting that the 50 MM exhaust port has 3.04 square inches of area.
as you know our engines are air pumps.
restrict the incoming air with a small filter and less flow.
restrict the outgoing air (exhaust) with small area and less flow.
build it right and you have minimal restriction at either end.
exhaust restriction is easy to measure...
tap into your turbo manifold, connect to a 0-150 pressure sensor w stainless steel brakeline.
here's the data from my design turbo manifold...
the logger shows i have more boost than backpressure up to 6107 RPM.
after crossover on this run i have only 27% more backpressure than boost.
excess backpressure not only drains power from driving the turbo but increases EGTs and adds heat back into the next intake stroke by virtue of overlap.
simply put you want all the heat out of the motor driving the turbo. to the extent you have backpressure you are losing the battle.
My intake port is the large one from pineapple and the exhaust one is the EP4a.
If I restrict my intake and exhaust areas, it will reduce my backpressure in the manifold. Is it what you're saying? I will also have less flow wich means less torque, I assume? Will I have a wider curve then?
Do you have a power curve with your manifold and 0.91 A/R ?
No Howard is saying to look at the system as a whole and find out where there is a restriction. The best way to make an air pump (the engine in this example) more efficient is to reduce restriction to flow. According to his post you are losing waaaay more power after your torque peak than you should be which usually indicates a flow restriction assuming you are not having ignition breakup or running out of fuel. He mentions adding a pressure sensor to your exhaust manifold to help determine where the restriction is occurring. Pressure will rise at the area in the system in front of the restriction and he shows an example of what his exhaust manifold pressure is on his setup for reference.
No Howard is saying to look at the system as a whole and find out where there is a restriction. The best way to make an air pump (the engine in this example) more efficient is to reduce restriction to flow. According to his post you are losing waaaay more power after your torque peak than you should be which usually indicates a flow restriction assuming you are not having ignition breakup or running out of fuel. He mentions adding a pressure sensor to your exhaust manifold to help determine where the restriction is occurring. Pressure will rise at the area in the system in front of the restriction and he shows an example of what his exhaust manifold pressure is on his setup for reference.
Yes, I got that point and I will measure it. I'll ask my questions another way.
Howard Coleman said:
restrict the incoming air with a small filter and less flow.
restrict the outgoing air (exhaust) with small area and less flow.
So my questions are:
On what purpose? Let's assume that the flow restriction occurs in the exhaust manifold. If I restrict the intake and the exhaust, I will have less air going through the engine, so I will have less backpressure in the manifold, right? So with a restricted intake and exhaust, will I have my peak torque at around 6200rpm? Will the torque curve decrease slower? If yes, I'll have surely less power/torque but a wider curve, right?
So, still assuming my exhaust manifold is the restriction, what you are saying is I can either replace my manifold and have high power with a wide torque curve, or restrict intake and exhaust and have less power but still with a wide torque curve?
It is hard to find. Who can provide a dyno graph with a s362sxe .91a/r ? I'm interested to see what it looks like on other cars!
Sorry this is a very late reply. No one is trying to tell you to ADD restriction anywhere. The point of taking measurements is so that you can FIND where the restriction is so you know where you need to make changes in order to ELIMINATE the flow restriction. You have either intake or exhaust restriction likely causing your problem so you need to find where it is and eliminate the restriction.
FWIW, I had a 13BT with the same Pineapple "large" intake port and ported the exhaust to open 2mm earlier.
With an EFR9180 IWG .92 A/R, I made peak TQ at 6500rpm and peak hp at 7500.
I never bothered to measure EMAP, but there was a big difference with my exhaust cutout open and closed - 2.5psi more boost and 65whp with the cutout open!
Peak Power run with cutout open (4" DP, 3" RB catback, 60mm cutout off downpipe)
just as a chain is as strong as its weakest link a flow system's capability is limited by it's most restrictive point.
there was a significant problem w the OP's system and it was the manifold. beautiful machinework but you can't beat the laws of physics.
the runner IDs are 1.625 in diameter or 2.07 square inches. the port is 3.04 square inches or 47% larger! considering all the work we do, porting, high flow turbos and intercoolers, to have it come to a screeching halt as it encounters the bevel on the flange. up go the EGTs and backpressure and down goes the push to the turbo. the drag increases w power so the top end gets choked.
i am not singling any manifold out here, just talking manifold tech to be of help. (i note the constructor now offers a larger runner option)
how much of a drag are small runners?
i recently evaluated my SXE 62 w a .91 hotside, the same turbo.
the OP made around 480 rw at 6700 and 366 at 7675 at 23 psi. not too bad as to peak power but 366 is really low and IMO a result of the high drag manifold.
i made 488 at 7649 at 20.5 psi. there seems to be over 100 hp missing up top.
restrictive manifolds, hotside housings and smallish turbine wheels cost drive to the turbo, raise EGTs and exhaust backpressure. this in turn adds non oxygenated hot gasses to the intake stroke... the last thing you want.
after evaluating the .91 i swapped in the 1.0.. lower EGTs by 40 F and 20 points less EMP. while most of the metrics were slightly better i was surprised that there was not a huge difference between the two. i did all my testing in third and was a bit limited although i did run the .91 to 8442 and it was till making 485 at 19.4 psi.
i am doing my EFR 9180 1.05 currently. at the same 7650 RPM it is 110 F less EGT and less backpressure than the SXE w the 76 wheel. it made 570 at 24.9 PSI at 7539. this was below 10 AFR and of course i will be leaning it out into the tens.
no knock anywhere on 93 pump and 1000 CC meth as AI.
i recently constructed 200 pages that deal w my take on the FD which will eventually migrate to my website. i invite you to visit especially my take on the engine systems featuring my low drag CPR manifold. check out pages 85-139 as well as the entirety when you have the time. i believe you need a gmail account.
should you have an interest in manifold/system design i invite you to read pages 85-139 of my 200 page FD comments located on Google Drive...
unlike the top tick power number from a dyno, races are often won or lost after you shift to the next gear... what do you have at 6000? mid range power determines when you get back to redline.
my system design focuses as much on midrange as top end.
i took a look at my EFR 9180 1.05 EWG 570 run to see what was happening at 6000.
i do run a 3 inch downpipe and my wastegate blends beautifully into the downpipe.
my focus is primarily where it counts, the turbo manifold.
Low Drag.
at 6050, 25.2 psi, i made 530 V 460 at 26 w the EFR 9180 .91 IWG (post 16).
at 6000 my EMP (exhaust manifold pressure) was 31.9 on 25.2 boost.
i have more boost than EMP until 5403 RPM
overall system design, rather than the hotside difference makes the difference.
The EFR 83 and 91 frame is slightly smaller than the SXE so the T4 turbo itself is a bolt in. One of my primary objectives was to position the driven wheel as close to the explosion/force as possible so the turbo positions almost equidistant from, and as close as possible, to the exhaust ports. this locates the compressor housing at the inner shock spring tower where there is less room and this is the approx area where the diaphragm needs to locate. i am a big believer in 60 mm Tial external wastegates, properly set as to duty cycle my boost plots looks like a straightedge at any level.
I do subscribe to the concept that almost anything is possible engineeringwise, Penske proved that by winning the Trans-AM in 71 with an American Motor s Javelin. My guess is the actuator would need to locate a couple of inches further forward and have a well engineered rod. there would be additional demands on control as my manifold delivers more flow to the driven wheel.
when i decided to part ways w the OE turbosystem in 02 i examined what was available at the 80 pounds per minute/600 hp level and found nothing appealing... times of course have changed. i decided to build a system employing two 42 pound per minute turbos. one for each rotor. i ran two Garrett TO4E 42 trim turbos. the turbos were internally gated. i ran two 3 inch downpipes merging into a Burns Stainless collector and each turbo had an outflow to my intercooler. i did have to be creative as to the actuators and control rods but they worked fine. my larger issue w the actuators was proper control. some outfit finally came out w a modular actuator that allowed me to switch springs. once i zeroed in on the right springs boost control was acceptable. (there is a thread somewhere on the project)
with the advent of better turbo options i designed my single manifold. i had acquired a picture file of manifolds that had over 50 to get me started. my primary objective is to run over 200 at the Texas Mile. one of the keys is that i will be in 5th gear (T56) around 575/600 for 17 seconds to 8700. heat cumulates and you need to get it on the driven wheel and out of the engine or you will have a meltdown. Normally aspirated race engineering provides the key and is covered in my Google Drive document..
here is a dyno run we did one week before my Oct 2013 Texas Mile to 205 mph/330 K/h:
11 seconds in 5th gear all at 575 or better ending at 8604. zero knock and EGTs around 1400F. (fuel E85 and 1500 CC of Methanol AI). Enormous cumulative heat created but Low Drag system made it a non event. the following week in Texas i backed it up as was running above 160 between the quarter mile and 3/8 marker when my fuel pump fuse failed and i collapsed my corner seal springs. i will be back in 2019 running on VP Q16 racegas and meth AI with my EFR9180 or maybe a SXE 69.
just as a chain is as strong as its weakest link a flow system's capability is limited by it's most restrictive point.
there was a significant problem w the OP's system and it was the manifold. beautiful machinework but you can't beat the laws of physics.
the runner IDs are 1.625 in diameter or 2.07 square inches. the port is 3.04 square inches or 47% larger! considering all the work we do, porting, high flow turbos and intercoolers, to have it come to a screeching halt as it encounters the bevel on the flange. up go the EGTs and backpressure and down goes the push to the turbo. the drag increases w power so the top end gets choked.
i am not singling any manifold out here, just talking manifold tech to be of help. (i note the constructor now offers a larger runner option)
how much of a drag are small runners?
i recently evaluated my SXE 62 w a .91 hotside, the same turbo.
the OP made around 480 rw at 6700 and 366 at 7675 at 23 psi. not too bad as to peak power but 366 is really low and IMO a result of the high drag manifold.
i made 488 at 7649 at 20.5 psi. there seems to be over 100 hp missing up top.
restrictive manifolds, hotside housings and smallish turbine wheels cost drive to the turbo, raise EGTs and exhaust backpressure. this in turn adds non oxygenated hot gasses to the intake stroke... the last thing you want.
after evaluating the .91 i swapped in the 1.0.. lower EGTs by 40 F and 20 points less EMP. while most of the metrics were slightly better i was surprised that there was not a huge difference between the two. i did all my testing in third and was a bit limited although i did run the .91 to 8442 and it was till making 485 at 19.4 psi.
i am doing my EFR 9180 1.05 currently. at the same 7650 RPM it is 110 F less EGT and less backpressure than the SXE w the 76 wheel. it made 570 at 24.9 PSI at 7539. this was below 10 AFR and of course i will be leaning it out into the tens.
no knock anywhere on 93 pump and 1000 CC meth as AI.
i recently constructed 200 pages that deal w my take on the FD which will eventually migrate to my website. i invite you to visit especially my take on the engine systems featuring my low drag CPR manifold. check out pages 85-139 as well as the entirety when you have the time. i believe you need a gmail account.
should you have an interest in manifold/system design i invite you to read pages 85-139 of my 200 page FD comments located on Google Drive...
This analysis is a beat of a stretch. You are comparing one guys setup that obviously has some sort of issues, to your's that doesn't have any problems. You have narrowed down his issues to the tubing size on his turbo manifold from pure conjecture. I can prove this is not true, and will do so below. The dyno below is from the very first dual gate manifold we developed on an S366 ( 1.1 a/r), with a 3.5" exhaust and a highflow cat. I do have the dynos from the .91, but will need to search from them as this was back in 2015. Now whats nice is the OP's manifold is a direct copy of ours, so we are able to rule out the notion that his tubing size is too small. The cast wheel S366 in the below dyno flows very similar to the billet S362SXE that the OP has, to be honest the S362SXE has the edge most of the time. I have attached both compressor maps.
Looks like I have to look harder, but this is the .91 dyno at 29/30 psi on E85. I believe the lower reading tq/hp run was just off spring pressure of 1 bar( 14.5 psi).
The 1.1 allowed 33 psi and 666rwhp. The forum member is on here too. This is a dynopack, that reads the same as a dynojet in my experience( I have used this exact dyno in AZ, many many times).
Obviously the S366 has the 80mm turbine wheel, vs the 74mm in the OP's. But Again this post is to rule out the notion that the tubing size is holding the engine back, obviously NOT true at all. Recently Rob's 3 rotor made 950rwhp with one of our manifolds on the same exact tubing size( and a T4 turbo). The entire world told him our manifold was too small, and he needed T6...
i have been logging exhaust manifold backpressure since 03 and was happy to find that Full Function Engineering came up w a really nice module that extends the pressure sensor's life. nice job FFE.
We use them on pretty much every build. I used to use an autometer boost guage, hooked up to like 10 feet of copper tubing( coiled up) back in the early 2000s.
Another note on this subject, I had Rob's 3 rotor monitoring EMAP( which is really easy since the Adaptronic has a spare internal 4 bar map sensor for EMAP). Going from a 1.25 to 1.44 turbine housing made close to zero power gains( it was like 15rwhp IIRC), and like a 2 psi EMAP drop. I've done this many times before going from .84 to 1.15, to 1.32 a/rs etc.
09-03-17, 03:40 PM
More top end power s362sxe ?
