Hypergear Turbochargers and High flow Services Development thread

[Dose Pipe Sutututu]

Thanks

Is the ATR43ss2 a lot bigger or ok for what I'm looking at? Don't mind going external gate, prob off exhaust housing.

This is for a track car.

go SS2 with the external hanging off the turbo.. I get full noise around 4100rpm in 3rd and it's on E85.. it is a touch bigger.. I would say 3076R size, but a touch more responsive.

hasn't seen a dyno yet, but Virtual Dyno tells me my shit box is making 317kW lol... however other cars have made over 350kW on stock cams with the same turbo.

I bash mine around the track quite often but takes getting used to.. the massive surge of power usually gets the car sideways (even with a 2 way).

[hypergear]

Firstly sorry for being lazy. But what is the best direct bolt in turbo for an R33 gts on E85 shooting for around 400rwhp with as much response as poss. Or is it worth going external gate and or big dump?

Standard high flow will do that fine.

[iruvyouskyrine]

I'll be tuning the internally gated one on BP98 with a Dynapack hub dyno, probably not as tough an audience as you guys are overall used to - though similar to some. Will probably go for around 18psi, but will see how knock limited it is and decide whether to go higher from there.

Attatched is my completely standard unopened 25 with internal gate SS2 on stock manifold and plenum, 1000cc injectors, Gtr intercooler, 3" exhaust, NISTune and 98PULP tuned on a hub dyno 21psi bleeding to 18.

[Lithium]

go SS2 with the external hanging off the turbo.. I get full noise around 4100rpm in 3rd and it's on E85.. it is a touch bigger.. I would say 3076R size, but a touch more responsive.

hasn't seen a dyno yet, but Virtual Dyno tells me my shit box is making 317kW lol... however other cars have made over 350kW on stock cams with the same turbo.

I bash mine around the track quite often but takes getting used to.. the massive surge of power usually gets the car sideways (even with a 2 way).

Whats full boost? 4100rpm in 3rd sounds less responsive than a GT3076R if anything

[Dose Pipe Sutututu]

1.5bar

[Lithium]

Yeah that is definitely laggier than a GT3076R - not bad for the price, that they seem to make similar power and the fact that they are a journal bearing turbo... goes well when you add up the costs of buying and installing one I look forward to experiencing it in person though and seeing what they're all about!

[hy_rpm]

Just remember that's in third gear

Most dyno runs are in 4th will be maybe 3800rpm in 4th

[Lithium]

Yep, I'm probably the last person you need to tell that to I never ran 20psi deliberately so admittedly I can't quote exactly what I ran there but used to hit ~1.1bar around 3700rpm in 3rd quite happily so I doubt it is any worse.

4th was a different kettle of fish altogether (would hit 17psi before 3500rpm):

Anyway - I (obviously) think the SS2 are a good thing, hopefully will have a better idea of how good soon... but I definitely like to keep it real, as well. Considering the price and convenience difference I think they deliver very very close to one of the most popular Garrett options.

[Dose Pipe Sutututu]

yo Lithium, if you want I can do some logs tonight and send them to you

Also I do have my gain set conservatively on the EBC - I find on the track it does like to spike a little thus my boost might seem a touch laggier.

I know I can get 1bar around 3500~3700rpm - just can't remember exact numbers...another thing to factor in E85 will make turbos a little lazier as the EGTs are lower but highly doubt it's noticeable lol

[Ben C34]

First I've heard of lazier boost response on e85 due to lower egt. ....

[Dose Pipe Sutututu]

First I've heard of lazier boost response on e85 due to lower egt. ....

another reason why some tuners prefer running lower timing as the car comes on noise to increase EGTs to get the turbo moving

[hypergear]

E85 was slightly laggier on my car also. Its not noticeable on road.

[GTSBoy]

First I've heard of lazier boost response on e85 due to lower egt. ....

But it's actually pretty self obvious. You would likely be able to make tune changes to get around it, as posted above.

[Lithium]

So do you guys use soft timing zones to try and induce better spool?

[Ben C34]

The cooler exhaust temp is obvious. The xtra exhaust volume due to burning more fuel still resulting in a slower spool is surprising.

Stao's examole was 100 rpm later.

[Dose Pipe Sutututu]

So do you guys use soft timing zones to try and induce better spool?

For 98RON I tend to make timing lazy to get it to spool harder, but with E85 I just smash in as much timing as possible to produce the most torque as possible for that RPM.

More torque = more exhaust flow, however all my experimentation is usually graphed in Virtual Dyno or "feel".. will be hiring a dyno soon to finish off my tune.

Here's my current timing map, quite a bit of timing through the motor - but she loves it.

[GTSBoy]

The cooler exhaust temp is obvious. The xtra exhaust volume due to burning more fuel still resulting in a slower spool is surprising.

Stao's examole was 100 rpm later.

It's not that you're burning more fuel. The amount of moles of exhaust gas is more closely related to the amount of air that the engine breathes. Granted, ethanol produces more H2O and less CO2 compared to petrol, and so there is definitely an increase in total number of molecules. Total mass of exhaust is also higher because of the extra mass of fuel involved. But there is definitely lower temperature, which not only impacts (downward) the actual volume flow rate of gas, but at the same time the total enthalpy of the gas and the velocity of the gas.

I haven't done the maths, and I'm not going to unless we turn this into a proper argument, but you could easily enough calculate the change in moles between the fuels, and given an assumption of a typical 98 and E85 exhaust temp for an otherwise the same engine load (say what? 75C?) you could calculate the actial volume difference, velocity difference, and with a bit more work the enthalpy difference. I think that most of us (inlcuding me) would be hard pressed to say how much of an effect the latter 2 of that list would actually change spool, and not very many more would be able to estimate the spool difference for the first 2 either. But you could look at the % changes and decide if you think it would cause the effect on spool to be +ve or -ve.

[XKLABA]

It's not that you're burning more fuel. The amount of moles of exhaust gas is more closely related to the amount of air that the engine breathes. Granted, ethanol produces more H2O and less CO2 compared to petrol, and so there is definitely an increase in total number of molecules. Total mass of exhaust is also higher because of the extra mass of fuel involved. But there is definitely lower temperature, which not only impacts (downward) the actual volume flow rate of gas, but at the same time the total enthalpy of the gas and the velocity of the gas.

I haven't done the maths, and I'm not going to unless we turn this into a proper argument, but you could easily enough calculate the change in moles between the fuels, and given an assumption of a typical 98 and E85 exhaust temp for an otherwise the same engine load (say what? 75C?) you could calculate the actial volume difference, velocity difference, and with a bit more work the enthalpy difference. I think that most of us (inlcuding me) would be hard pressed to say how much of an effect the latter 2 of that list would actually change spool, and not very many more would be able to estimate the spool difference for the first 2 either. But you could look at the % changes and decide if you think it would cause the effect on spool to be +ve or -ve.

Proper argument, proper argument !!!!!

I would be interested to see the math on this, and there is extra %s for showing the workings

[Badgaz]

My money is on gtsboy

[Badgaz]

Lots of fire science helps here.