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German Time Attack Car - Max Performance with N3G1 Turbo
Hi,
at the moment i have to Rebuild and Upgrade my Engine. Next Saison I want to start in the "Club" class in the Time-Attack Series. The OEM Turbo is necessary, so i cannot upgrade the Turbo.
My Car is a 2001er Type-R. Now... i am undecided what and how i Upgrade the Engine Parts?
My Plan is:
- Porting (Which Porting? is the Porting style equal when i Race with E85 or with normally Fuel?
- Running on E85 or Stock Fuel? How much Horsepower bring a Set-up on E85?
- If u Upgrade on E85, what is about Premix? Still Premix with the Mikuni OMP?
- Which Fuelpump and Injectors? This is addicated which fuel I ran..
One Pump, Two Pumps and so on...
My first priority is to find the right Porting for stock N3G1 Twin Turbos. I Didnīt find anything about it. Has somebody some experience? Will a large Streetport work?
The problem with classes that allow few modifications is you have to read the class rules very carefully and take every small advantage that you can.
We can't really help you without knowing the rules.
If you are allowed either normal low octane pump fuel or E85, there is no doubt that you should be running E85.
You will want minimum 4x 2000cc injectors and a lift pump in the gas tank to a swirl pot with 2x Bosch '044 pumps for the 400-450rwhp you can get out of the stock twins on E85.
There is special premix just for Ethanol fuels- use that.
Without knowing the rules.... we can't really tell you how to proceed on anything else.
Example- stock twins.
Do you also have to use the stock exhaust manifold and the bit between the two turbos? Or could you take the turbo exhaust housings off the collector and spin the rear turbo around and run 2x downpipes and a nice straight inlet to the 2ndary turbo.
External wastegate allowed or just stock un-ported internal wastegate? If allowed parallel stock twins on a different exhaust manifold, but not external wastegates are you allowed to use the old pre-spool valve as a second internal wastegate?
If you can use a different exhaust manifold, this opens up the possibility of using a different intake manifold.
What are your restrictions on transmission and gearing and what are your race courses like?
If you have some leeway with gearing and just 1 standing start where you are at low rpm- it might be best to just go with a rotated 2ndary turbo in a parallel turbo system for simplicity and room for your intake set-up. Your powerband will be restricted to 4,500-9,000rpm but that is workable even without a close ration sequential transmission.
Any porting? All porting?
I would choose a short wide semi-peripheral intake port with side ports to help cool your apex seal for reliability and increase low/midrange torque. Just port the exhaust for a little earlier opening and shape on a flow bench for best flow.
I would leave the side housings and their ports stock so it is easy to swap out parts for repairs and maintenance. If you break a side housing are you going to have time to port a new one and swap it in or will you have to rebuild with stock ones and re-tune? Better to put your modified porting on the rotor housings and have a spare set of those in my opinion.
Maybe all this race car engineering isn't necessary though....
The RE Amemiya "Touge Mahoo" went up against dedicated track FDs (including 3x single turbo sequential gearbox time attack FDs) and won on the Tsukuba circuit (a small track) even with its "boost up" stock sequentials.
In fact, the "Touge Mahoo" started from the back and worked its way to the front.
Intro to each car in 1st video with the cornering speed challenge, 5 lap Tsukuba battle starting 4:30 in the 2nd video.
The stock sequential probably had less power and a softer response. The single turbo's look to be tuned to drift and have harsh response, like its an on off switch.
I mentioned this earlier that I was looking at a larger efr 9180 for the softer response but still powerful.
Lots of things come into play when tuning a car and people prefer different set ups.
I like wide wheels, soft spring rates, high damping ratio's, and I am searching for a softer yet powerful single turbo. I think the EFR9180 at lower boost will work well.
I actually found the opposite between soft response and immediate response on turbos on my cars.
With soft response turbo you floor it, listen for the WG to creep open and then half pedal it while the power comes in suddenly and then throttle in or out from there depending on grip.
You have to 100% commit to throttle on and riding out power over steer because if you lift throttle any significant amount you are back to having to spool the turbo up.
With immediate response turbo you gently squeeze the throttle and throttle in or out depending on grip. You are free to let off the gas instead of riding out power over steer because the power will come back immediately.
Those cars were stock sequential and the singles were big T04Z 500 on the T/A car and 580rwhp on D1 car Keiichi drove.
I think that video also shows the immediate response of the stock sequentials is easier to drive even for the pros (not to mention having 100 to 200hp less on street tires helps too).
It also shows how a very well developed and well rounded car can be more than a sum of its parts.
I wrote with our Time-Attack organizer and i can everything change/upgrade except the Turbos.
So, Mainfold, Wastegate and so on is allowed.
Now, my Race Car isn`t a 100% Race Car. I am driving it on Street, at the Weekend as a Summer Car
E85 is allowed... the next Gas station is about 5Miles away. I think we would go on E85. I can make a second map for Normal gas ...
But for what is E85 good? Lower Exhaust Temperature? More Boost?
When i can go to the max without E85. How much will E85 add? Here in Germany... nobody drives it :/
My another is:
- Complete 3" Exhaust without a catalytic converter-
- Pettit Cold Air Intake
- Pettit huge SMIC Set.
I think this would be the best Setup for the twins.
Is it usefull? Do u Think this is usefull and Necessary?
What is about going non Sequential? I read this would be add some Lag. Do it add enoguh Horsepower? I Like my Setup at the moment. No huge Turbo hole or something else. Perfect for Weekend driving.
Transmission have to be Stock. I don`t have enough money this year to go for a Dogbox or something else
E85 - with E85 you can run more boost, safely. You also have to run substantially more fuel for the same power levels. You also need to make sure you have E85 safe fuel components (basically you will need a whole new fuel system..injectors, fuel pump(s), fuel hose etc). How much power will it add? who knows..depends how hardcore you get.
In regards to the external wastegate setup in the link, im pretty sure that guy has the highest hp car that's still running the twins (upgraded twins though) if that's anything to go by.
Really, a wastegate is a boost controller, not power adder..so I think if you get to the level where you cant keep the stock gate closed then start thinking about that.
non-sequential isnt really a power adder either. its a simplification, and the cost is a bunch of lag. It can net slightly more overall HP, i guess because (when done properly) restriction is removed from the turbo setup (flapper).
I personally feel both the non-seq, and the external wastegate are a step sideways and you should be taking steps forward
IMO your time and money would best be spent with suspension, wheels, tyres, modern injectors all round, modern ECU, quality sensors, real cold air intake, exhaust, brake upgrades, chassis braces & weight reduction.
E85 usually improves spool a bit and peak power by cooling the intake charge and as you say it also results in lower EGTs.
It also allows for more boost as it has a higher octane number.
You will start to have turbo reliability issues with the stock turbos from shaft flex taking out the compressor seals and up to causing shaft breakage.
They will live fairly well at 14psi and not as well above that boost for long periods of time. People drag race them at 17psi- not sure how long they would live on a road course at that boost. You could try to get them rebuilt and VSR balanced for a really high rpm, shaft breakage is often because a harmonic happens outside of stock operating parameters (shaft RPM).
I saw that thread on the external wastegate on the stock twins. You could do that and stay sequential if you wanted or go parallel- probably will not have as dramatic affect on 100% stock twins as I think they will be more limited by the compressor side. Still, it can't hurt!
Parallel stock twins on the stock manifold is just simpler, but you lose most your power under 4,500rpm.
If you did stock twins parallel on a custom exhaust manifold, you still wouldn't have good power under ~4,000rpm because of the turbos surge lines together (its not just a matter of having enough exhaust energy to spool them), but you could gain some peak power from lower intake and exhaust restriction (rotated 2ndary turbo).
Stock twins on a custom manifold whether sequential or parallel would also free up room so you could run whatever intake manifold you wanted.
You could go ITB style with something like a Projay manifold and a 4150 style 4 barrell manifold or you could go semi-peripheral port like I said with a Projay manifold or the CX racing more stock like lower intake manifold.
A really big and efficient intercooler without too much pressure drop will be important because you are really pushing the stock twins to where they are blowing a lot of hot air.
I have thought about this stuff a lot since the class I race my FD in must have 100% stock engine "block" with only balancing and 100% stock turbos (but any manifold/extension housing/exhaust).
I have a design for what I hope would be a low pressure drop water to air Laminova intercooler and ITB set up that sits on top of the engine (far back)- let me know if you go that route and I can share.
Air to air is probably better if you are going to do anything longer than short sprint races and you don't have a minimum weight you are going to try to ballast up with using additional water.
In regards to the external wastegate setup in the link, im pretty sure that guy has the highest hp car that's still running the twins (upgraded twins though) if that's anything to go by.
Really, a wastegate is a boost controller, not power adder..so I think if you get to the level where you cant keep the stock gate closed then start thinking about that.
I don't agree. More wastegate flow is a power adder.
On this forum I have seen ~400rwhp cars gain or lose ~30rwhp just from whether their external wastegate was open vented or re-routed into the exhaust.
Similarly, Balljoints external wastegate mode gave him something like 30rwhp over the previous BNR twins record that used just the ported stock internal WG.
But... these were on cars that the turbo compressor still had some flow potential on the table. I think on the stock twins where the compressors will be maxed out, there will be less gain.
The engine system volumetric efficiency should improve, so boost will drop and since the turbo compressors are maxed flow will not increase to push boost back up- so there will just be the power gains from higher efficiencies (lower boost/intake heat, less pumping losses on exhaust side and lower EMP from lower boost).
I used a 60mm external wastegate on my S5 TII stock hybrid. It didn't make any more power than I would expect from a T04B 60-1 HiFi compressor, but it did make it at lower boost than I would expect. 340rwhp at 10psi boost creeping to 11psi, 375rwhp at 16psi and the turbo maxed at 380rwhp at 18psi boost or however much more boost I tried.
Let me tell you, there is A LOT of flow out of the wastegate on a ~400hp rotary. You hit max boost ~3,000rpm making just ~120rwhp and then rev to 8,000rpm making over three times that power (and exhaust flow) along the way.
WG exhaust is blowing away the steel tray you have on the concrete floor trying to avoid the scorch marks.
In regards to the external wastegate setup in the link, im pretty sure that guy has the highest hp car that's still running the twins (upgraded twins though) if that's anything to go by.
Really, a wastegate is a boost controller, not power adder..so I think if you get to the level where you cant keep the stock gate closed then start thinking about that.
I don't agree. More wastegate flow is a power adder.
On this forum I have seen ~400rwhp cars gain or lose ~30rwhp just from whether their external wastegate was open vented or re-routed into the exhaust.
Similarly, Balljoints external wastegate mode gave him something like 30rwhp over the previous BNR twins record that used just the ported stock internal WG.
But... these were on cars that the turbo compressor still had some flow potential on the table. I think on the stock twins where the compressors will be maxed out, there will be less gain.
The engine system volumetric efficiency should improve, so boost will drop and since the turbo compressors are maxed flow will not increase to push boost back up- so there will just be the power gains from higher efficiencies (lower boost/intake heat, less pumping losses on exhaust side and lower EMP from lower boost).
I used a 60mm external wastegate on my S5 TII stock hybrid. It didn't make any more power than I would expect from a T04B 60-1 HiFi compressor, but it did make it at lower boost than I would expect. 340rwhp at 10psi boost creeping to 11psi, 375rwhp at 16psi and the turbo maxed at 380rwhp at 18psi boost or however much more boost I tried.
Let me tell you, there is A LOT of flow out of the wastegate on a ~400hp rotary. You hit max boost ~3,000rpm making just ~120rwhp and then rev to 8,000rpm making over three times that power (and exhaust flow) along the way.
WG exhaust is blowing away the steel tray you have on the concrete floor trying to avoid the scorch marks.
How can more wastegate flow be a power adder? that goes against the fundamentals of what a wastegate does...more wastegate flow = the ability to run less boost & dump exhaust quicker
I think I know what your saying, but IMO the gains in the above twin turbo cases come from getting rid of the restriction in the stock manifold and the ability to hold the boost stronger & longer.
Gas only goes through the wastegate when its open (and dumping exhaust AWAY from the turbine) - so how can that help it spool?
IMO the ability to hold the wastegate closed longer without it creeping open, and the extra efficiency from getting rid of the flapper etc is where the power gains come from
How can more wastegate flow be a power adder? that goes against the fundamentals of what a wastegate does...more wastegate flow = the ability to run less boost & dump exhaust quicker
Its easy- the wastegate is an additional flow path for exhaust for when the turbo already has enough exhaust passing through it to maintain the desired boost.
Here, I will post a pic showing boost and AFR from my own FC 7670 build.
See that highest boost run- that was with the boost line disconnected from the dual 44mm wastegates. See how fast the engine Volumetric Efficiency crashes from too high Exhaust Manifold Pressure when trying to push all the exhaust through just the 1.04AR T4 exhaust housing?
The other runs are with functioning wastegates. The wastegates allowed me to make 90 more horsepower peak and a lot more top end power. All while running lower boost.
On a rotary it is a different story then on most piston engine cars where once the turbo hits full boost that is peak torque and everything after that is downhill in terms of torque.
^ Interesting, so its basically just reducing back pressure, and the decrease in overall back pressure + increased overall flow is enough to offset the flow that is diverted through the wastegates and away from the turbine?
Sounds like manifold design would play a big part in that. It would be interesting to see some graphs with a manifold with really high priority wastegate placement and large gates, and some without (i know thats not going to happen). In theory there must be a tradeoff to be had, or a sweet spot between diverting flow away from the turbine (decreasing overall back pressure) and having it go through the turbine, especially with large gates.
Yup, the engine and turbo are a really dynamic system with lots of variables.
I guess the piston engine guys do use increased wastegate flow to make more power too. I wasn't thinking about the guys who use stock or small turbos and max them out for auto-x on piston cars
They commonly run lower boost toward redline to make more power. EMP drops system VE rises and power increases over running the same higher peak boost all the way to redline.
So, since power is up (bigger boom) we know there are more exhaust gasses, but the increased exhuast is flowing through the wastegate (since target boot is lowered so turbo needs less flow).
When I go on E85 I have to usw 4x2000...but if I drive on Normal Gas, the Duty Cycle is to low. Would it be a problem?
My another Setup, Braces/Brakes/Suspension is great and well balanced. I am so much faster than many other Cars in Corner Speed, that is really incredible
Next Year the E85 Fuel will be Banned from Germany`s Gas Stations! Why? I don`t know
so....back to the beginning. I have to run on normally Fuel (102 Octane) now.
My Current Setup would be:
- Full dymanic Balanced excentric Shaft incl. new Clutch (I Think Exedy Stage 2) an very light Flywheel. (fix)
- No Air pump (fix)
- Pettit CAI (fix)
- Pettit Intercooler Kit (fix)
- Full 3" Exhaust (fix)
- New Seals (rebuild Kit), OEM, Aktins, Goopy? Any Experience?
- 340 Aeromotive Stealth Fuel Pump
- 550ccm primary 1300secondary Injectors would be enough for the max. performance of my twins? Or 850/1200? (From: TurboRX7.com > Fuel System Facts)
- Is a new Ignition System Like the HKS Twin Power Usefull and necessary? ON the Review everyone told that it will gain +20-30 HP???
- Apexi Power FC. I will manage it myself. I think it is a good ECU for DIY?
Did I have forget something?
- New Wastegate will I do Later I think when it is necessary.
- Closed Gear Ratio too.
I don`t know who are my rivals. It is not fix if there is only a Club class or a Club AWD and a Club RWD Class. Every Street Car would be my Rival. Like 911 - Corvette - and many JDM`s but no GTR. He will start at a Higher class.
we switched to E85 in the race car this year and as a race fuel i really like it. the race car is a miata, and we picked up more than 5hp everywhere, which is pretty huge on an 1.8l non turbo!
it feels like nicer stuff to deal with than regular gasoline, it does smell better, and you can dyno all day without smelling like you dynoed all day. you will still feel like crap though, so it just feels nicer, but probably isn't.
it also is much less sensitive to mixture and timing, going from 10:1-14:1 afr makes about a 2hp difference. timing is the same, pulling 6 degrees makes about a 2 hp difference. on gasoline it was much more picky.
the miata, being non turbo was also able to switch to E85 with the completely stock fuel system, although since more fuel volume is needed, we did need an ecu, but we needed that on gasoline too.
that being said, if you need to run gasoline 102 is more than enough, the Japanese basically don't run race gas, because its too expensive.
as far as the rest of the car goes, i'd just copy the JDM setup, its a stock, or mild ported engine, HKS racing intake, V mount of your choice (HKS or Greddy), they are running a full exhaust, 3" or 3.5". they will be running the HKS Fcon Vpro, or maybe even a flashed stock ecu. and that is pretty much it, the Japanese try to keep things simple. some tuning and its 400hp, which is more than enough.
That turborx7.com info is fairly old, reworked stock injectors and/or 1680s, stuff that for a joke!
If you want to retain the primaries, that's ok, I'd opt for EV14s secondaries 1300s, as a preference on petrol.
Dunno if the japanese do a 3.5 downpipe, they're normally 80mm at best, SMB do one which will clear the steering if you want to shell out.
Twin power gaining that amount of hp is in the realm of fantasy. There's better ecus out there than the pfc now without the idiosyncrasies, no need for wastespark and buying datalogits either.
Originally Posted by j9fd3s
as far as the rest of the car goes, i'd just copy the JDM setup, its a stock, or mild ported engine, HKS racing intake, V mount of your choice (HKS or Greddy), they are running a full exhaust, 3" or 3.5". they will be running the HKS Fcon Vpro, or maybe even a flashed stock ecu. and that is pretty much it, the Japanese try to keep things simple. some tuning and its 400hp, which is more than enough.
Ease of 400hp, assuming at the wheels, on twins seems a bit overstated, I've never seen one here without dyno trickery. Pretty much every hks intake I've seen has debris in the intake track and worn compressor wheels too, before even getting onto the temperature side. I'd expect there's a few pics from this weekend of the Japanese WTAC Rx7 - and others - to steal an idea or two.
Pretty much every hks intake I've seen has debris in the intake track and worn compressor wheels too, before even getting onto the temperature side.
well they all run it.... look at the videos above every single one has the HKS RS intake on it. so maybe, instead of overthinking an intake, maybe you just run that one, and then overthink something else.
we have a K&N on the miata, and there is more dirt on the inside of the intake pipe than the outside
Maybe all this race car engineering isn't necessary though....
The RE Amemiya "Touge Mahoo" went up against dedicated track FDs (including 3x single turbo sequential gearbox time attack FDs) and won on the Tsukuba circuit (a small track) even with its "boost up" stock sequentials.
In fact, the "Touge Mahoo" started from the back and worked its way to the front.
empirically hp and weight have an effect on lap times, but it doesn't seem to be linear.
in fact where the weight is in the car seems to be more important as how much the car weighs. the FD is quite blessed here, as its really well balanced from the factory. this one time we were racing an E30, which is a terrible car. its a danish cookie tin with an engine from a WWII submarine. so the whole thing is fairly light (~2550lbs, with driver), but the ballast* they use for an engine is about halfway in front of the front wheels, so the weight distribution is easily 60/40, if not 70/30.
so we ran one, and then added the ballast needed to get up to the minimum weight for the class, which was 2750lbs, with driver, so we added the 200lbs of ballast to the trunk.
you would think 140hp/2550lbs car would be faster around a road course than the 140hp/2750lbs car, but the 2750lbs car had a much better weight distribution, and was actually quicker by about 1/10th of a second.
*the E30 engine is HEAVY, fully dressed with a transmission it is easily 1,000lbs, and only makes 168hp at the flywheel. i will grant you that the BMW engine will do 168hp all day, and then again tomorrow (and the day after that), but the FD engine is only 450lbs
we have a K&N on the miata, and there is more dirt on the inside of the intake pipe than the outside
Yeah, I'd agree they're very ordinary, The factory team here did tests on a variety of aftermarket filters, something like 20 or 30 and came to the conclusion the stock panel filter was best...in a pressurized airbox.
I think your weight for the engine might be off, dressed with turbos and manifold, I've come up with something around 160kg when going through this process before. I'd expect the 3.7 litre V6 in recent Mazdas/Fords to weigh less for something approaching equivalent capacity!
10-07-15, 05:16 AM
