TX2k18 street racing

[badcobra]

Ain't no way these turbos spool early. They don't light off until 5g with an .81 turbine housing. My converter is a tad too tight though, gonna loosen it up. But here's the deal, if the turbos did spool at 3g you'd have major traction problems to contend with. Coyotes have a wide powerband, spooling at 5g is no big deal. People get way too caught up in that imo

 

[gimmie11s]

What is the turbine A/R? Something around 0.81 will spool hellafast compared to 1.00 or 1.10

I would imagine a 67/65 with a 0.81 A/R would start to spool at 2.5k, while a 1.10 would be closer to 3.5k at the start of the ramp.

Turbine housings are .81

Ain't no way these turbos spool early. They don't light off until 5g with an .81 turbine housing. My converter is a tad too tight though, gonna loosen it up. But here's the deal, if the turbos did spool at 3g you'd have major traction problems to contend with. Coyotes have a wide powerband, spooling at 5g is no big deal. People get way too caught up in that imo

That's kind of what I thought you'd say.

Not sure if you're still 4.6l or what size your motor is, but the 5.0 and 12:1 compression of the Gen 3 coyote will be in my favor assuming youre still 4.6 and lower compression.

I really want these to be at full boost by no later than ~4500 rpm.

Here's to wishful thinking!

 

[badcobra]

Turbine housings are .81



That's kind of what I thought you'd say.

Not sure if you're still 4.6l or what size your motor is, but the 5.0 and 12:1 compression of the Gen 3 coyote will be in my favor assuming youre still 4.6 and lower compression.

I really want these to be at full boost by no later than ~4500 rpm.

Here's to wishful thinking!

Motor is a 4.6 with close to 11:1 compression. Unfortunately it's a myth that compression spools turbos. The extra cubes won't hurt though. Good luck!

 

[gimmie11s]

Motor is a 4.6 with close to 11:1 compression. Unfortunately it's a myth that compression spools turbos. The extra cubes won't hurt though. Good luck!

Compression helps. Although not as much as displacement.

I ran a 62mm turbo on a 2.0 four banger and spool increased by about 250 rpm once I added 2 points of compression after building the motor.. all else being equal.

Tuner will be able to play with cam timing too and hopefully bring them in a little early.

We'll see i suppose.

 

[BigPoppa]

My 66mm turbine twins with .81 A/R start building at 2.5k. If your running a setup with a smaller turbine and it takes 5k to start spooling, I'd check the settings on the boost controller.

Something around the size of a 76/75 with a .81 A/R would spool around 5k.

Turbine size and turbine A/R are the heaviest factor in determining spool time. The compressor side does affect it slightly, but the effect is negligible compared to turbine side.

Just to make sure we're on the same page, were talking about when the turbo starts building boost or when you are at target boost? I'm referring to when boost starts to build.

 

[gimmie11s]

My 66mm turbine twins with .81 A/R start building at 2.5k. If your running a setup with a smaller turbine and it takes 5k to start spooling, I'd check the settings on the boost controller.

Something around the size of a 76/75 with a .81 A/R would spool around 5k.

Turbine size and turbine A/R are the heaviest factor in determining spool time. The compressor side does affect it slightly, but the effect is negligible compared to turbine side.

Just to make sure we're on the same page, were talking about when the turbo starts building boost or when you are at target boost? I'm referring to when boost starts to build.

Yes definitely agree however hot side is not the only determining factor when it comes to spool.

What size are your compressor wheels? 62s im guessing? The spool difference between a 62mm compressor and a 67 is definitely not negligible.. I wish it was lol.

Also.. im more curious about the rpm with which full boost is achieved (target boost as you call it--actually a better way to describe).. im not really worried about when it starts building boost.

 

[BigPoppa]

Yes definitely agree however hot side is not the only determining factor when it comes to spool.

What size are your compressor wheels? 62s im guessing? The spool difference between a 62mm compressor and a 67 is definitely not negligible.. I wish it was lol.

Also.. im more curious about the rpm with which full boost is achieved (target boost as you call it--actually a better way to describe).. im not really worried about when it starts building boost.

I'll have to check to see when they reach target pressure. With the settings I've got now, the boost curve looks like a step change as opposed to a curve. I'll see if I can dig up some old dyno charts I've got pack ratted away.