Blackonblacksls

Having to add backpreasure to control boost seems like a terrible compromise..

Do you have the old gates??

Could you add the old gates in their factory position on top of the second gates you added?

Turbo-Geist

No there's no room. These take the space of where the old gates used to be.

stevieturbo

I know it's more work...but I'd be wanting to modify as described before, for a couple of reasons.

Firstly...so you have total control over boost without compromise...and secondly as mentioned too, to ensure both turbos are working as evenly as possible.

I'd want the gate takeoff on the turbine housings on both, in as identical a location as possible so you dont have a scenario where one turbo is doing far more work than the other which could very easily happen.

You might also find that re-routing the gates back into the downpipes could also reduce boost at the top end. But even that can be hit or miss and dependent on other variables.

Turbo-Geist

Yes, I think I'm finished modifying this turbo kit. It works perfectly for a LS1 or LS2 with cathedral port heads looking for a range of ~ 650 to 1100rwhp. It has also been proven to have better control on 4xx cubic inch engines if you are willing to run 2.5" downpipes and a traditional C5 style catback exhaust system.

It's also very fun at 18 psi on a 427 as long as you can manage the power on the street.

Turbo-Geist

I drove the car to the dyno on Friday to do some tuning and add power. Here are all of the dynosheets of this combo for comparison. On 18 psi, the mustang dyno reads about 140hp less than the dynojet which is inline with the estimated 10 to 15% difference that is typically quoted.

Dyno Comparisons:

12/23/2015
994/904 - 18 psi - Dynojet



7/15/2016
855/811 - 18 psi - Mustang Dyno



2/10/2017
857/888 - 18.5 psi - Mustang Dyno
927/999 - 21.5 psi - Mustang Dyno
945/1029 - 23.1 psi - Mustang Dyno

Turbo-Geist

Here's a pull with no CO2 applied to the wastegates and letting it creep from 5psi to 18psi:

735/633



Here's the 23psi pull viewed using a different graph:

940/1031

schpenxel

That torque...

Turbo-Geist

A log of that pull. It's all there by ~3800 rpm. It actually spiked to 24ish and then settled in to 23psi with a little tire spin.

schpenxel

Looks like fun

Turbo-Geist

We shall see. Track rental Feb 26th.

HamadoZr1

Hello Guys I wanna ask about the CNC Heads from WeaponX?

My C7 Zo6 has, 2.31 upper pulley+ 9% harmonic balancer+ air intake filter+ LMR heat Exchanger+ 160 Thermostat+ D3P shroud fans, My question is if I installed the CNC Heads do I need to install the camshaft with it or the stock camshaft is enough? One more thing If I need to install the Racing camshaft I do not want the aggressive camshaft I hate the loud sound.

help please.

Turbo-Geist

21.5 psi and 23 psi pulls compared to the pull with no CO2 applied. Over 400 ft-lb difference in torque.

Turbo-Geist

Try this forum -> https://www.corvetteforum.com/forums...n-nitrous-173/

o1Z0sick

That's some nasty torque at 4K. Can you please post a video? I want to hear the open dumps, I will be doing that soon.

How did you manage 77lb-ft going from 18 to 18.5 psi? Did you have CO2 on the latter?

That creep curve looks identical to a centrifugal. Pretty cool.

I definitely agree with your assessment on maxing out this kit and how it is better suited for a smaller ls1/2. I think the main factor is turbine flow and using T4 flanges with a 70ish exducer turbine is the ticket on a 427. Huron?

Turbo-Geist

When it was dyno'd before it had a C02 leak and the direct port kit so it didn't spool and hit full boost as early.

Here's a video from the 21 psi pull. Not sure if you can hear everything well enough. Also, at 21 psi, there isn't much flowing out of the WGS

Turbo-Geist

Thx. This is with a 3# spring in the gate and I'll have to look back at the log. I think it makes 5 psi around 3000 rpm and climbed to 16 or 17 on that pull. It's a little late to the party on the street. I could play with CO2 and ramp rate and get it to act like a 5 or 7# spring and it would probably be just right.

Which turbos are you referencing with a 70ish exducer turbine? I'm ready to try a different turbo location and considering building my own twin kit later this year.

StealthFRC

sounds exactly like my car lol

Turbo-Geist

I wonder why?

When are you going back to the track?

StealthFRC

when there isn't 2ft of snow on the ground lol. My guess is April sometime.

o1Z0sick

JDS's T4 flanged manifolds and 6870 PTE's ported s cover. I have seen 980 ft-lbs at 5470rpm on 18# gates springs. I'm trying the 7075 comps with ported CT4 cover so hope they work out as well.