Hello,

I have finally registered after lurking for years. My previous car was a C5 z06, and I've owned this Rx-7 for a little over 4 years now. When I purchased the car it had the basic bolt on mods and a street-ported engine. The mods were apexi pfc, downpipe, RB single tip catback, and an intake. I brought it by a local dealership and they told me the car was mechanically sound. I found a local shop on here, Turblown, and they showed me otherwise. They installed a water/alcohol injection kit, an ambient air intake( where the R2 oil cooler would be), and did some toe end links, fuel filter, and a full fuel system(1680cc secondaries/FJO injection driver/FPR etc). Last year the the twins went out, and I opted for them to build a new engine and go the single turbo route. The old rebuild was a turd as I was shown, and that is what we figured anyhow. Fast forward to what I had done;

- ALS seals, small street-port, studs, coated bearings/oil pump, loop lines
-Xcessive Oil Pan
Gt3574( P trim T4 1.15 Garret GT35R) @ 16psi
.120" wall 304L manifold, 3.5" downpipe, hardlined coolant and oil lines, Tial 44mm waste-gate to atmosphere
3.5" Muffled Midpipe
Switch from 600cc of methanol to 50/50
Custom Greddy Intercooler installation with Ron Davis Radiator
Knightsports Style Vented Hood
Tial Q 50mm bov
Remote Oil filter
Premix
Tweakit Idler
Relocated Battery to passenger side bin



This car is a hell of a lot faster than my old z06. The tires boil on the freeway. I was told my someone following me that it lays two big patches down.
We are hitting the dyno later this week. I will post video and the sheets. Here are some photos;

 

Congrats! Glad you kept with the rotary. Hope to see those dyno numbers.

 

Nice build..

 

i may sound a bit daft here or this might be because the pics were taken when you were still working on the engine bay, put where are your radiator fans? the oil filter looks like it would get in the way when you come them in, are you going for some slimline ones?

 

Come pickup your car

1.15 Bar, 13degree ignition adv, 1100 degree F post turbo EGTS

448rwhp, 388 ft lbs of torque. Not bad for a tiny streetport and 61mm of turbo..

10psi by 2800rpms

Ran into a bottle neck at 6200rpms, was on its way to more...

 

^ That's the most low rpm torque (3k and below) I've seen out of a 13b single turbo set-up. That full range power curve really makes the complicated twins seem worthless. Great job!

 

This is the plain-bearing 3574? I've now seen a few really nice dynos out of this turbo.

 

love Sean's GT3574...

i have always believed that journal bearing turbos are under-appreciated... not saying they are better than BBs, just that the diff is much less than most realise.

also, the big deal w the GT3574 is the hot side.

consider:

GT3582r

compressor average sq inch area: 6.386

turbine average area: 5.171

GT3574

compress area: 6.386

turbine average area: 5.89

cheap and deadly

are the dyno numbers SAE?

hc

 

This isn't Sean's turbo. I didn't realize until recently that we've been running this exact turbo combination for at least 4/5 years. I just never threw a catchy name together, I always called it a P trim GT35R...

Dyno numbers aren't SAE. Can I have them corrected to SAE? I am not super familiar with chassis dynos. Only reason we use one really is so we don't have to get arrested tuning a car in 4th gear on the street, and its always nice to be able to look under the hood for a 4th gear pull...

 

Yup, pretty good spool for a T4 1.15 huh? I did seperate the pulses on the exhaust manifold( up until the w/g opens). If you look closely there is a divider going up to the wastegate valve.

 

"exact turbo combination for at least 4/5 years."

congrats on that.

 

Lookin good.....but I have a couple of questions about the dyno sheet.....

1. Why was the pull aborted at 6000rpm?
2. what was the Air fuel ratio at higher RPM (looks like a leaning trend in the graph)
3. what was boost at 4000rpm vs 6000rpm
4. why was the input weight changed?..

.....in the future try using one side of the graph for your HP/Tq scales and the other for Afr's or boost....just a suggestion

 

We started experiencing a little bit of ignition breakup. Not sure what the culprit is. Car has a new set of OEM wires, and 9 plugs, MSD 6A with a T2 L coil. We have another car that is identical that we are going to run next week, only we have the greddy plugs, twin MSD 6As and MSD coils.

That is not the best representation of AFR. We did almost 20 pulls, and didn't print every one. We ended up 13.1 out of boost, 12.9 up to 5psi and 11.8 to 16psi, past that it was tapering down to 11:1. Keep in mind there is water/alcohol injection and only 13 degrees total ignition advance from 15+psi

After we did a few pulls a subie tuner showed up and I had him resync the car and make sure all the dyno input numbers were correct. I just wanted to verify that everything was correct. He pulled up the MustangDyno's database and inputted their specifications.

 

got it... looks like it will make GREAT power at redline....

 

maybe pick up a set of Greddy 7420's? 10's leading 12's trailing... Expensive but damn good plugs.

 

That seems to be the general consensus. Do you have any experience with them? It seems everyone recommends them but can't clearly explain why.

 

Greddy rebadges them as their own race plugs, and Ari over at www.RX7.com swears by them. They were used on the American Flag record-breaking drag car.

They have a resistor (R) which is a plus for rotaries running a CAS wrt EMF, they are the proper length and socket size, and (most importantly) they have the small iridium electrode with ground strap.

To quote Ari, "These things will fire even if they're immersed in a bucket of oil"

 

I'm not going to **** on the OP's thread he has a nice car and elliot got good results, I'm just going to give his memory the benefit of the doubt on the time line.

~S~

 

wow, this thing looks and sounds like a beast.
I really need to meet Ari in person, I've spoken with him a number of times over the phone and done quite a bit of business through him and he seems like a realy character.

 

nice build

 

nice setup, its about the same setup i was planning to run

 

This is very impressive. However, the large turbine A/R contradicts what I've read about quickly spooling a turbo.

From the Honeywell/Garrett webpage:

So why is it then, given the above statement from Garrett, that the large A/R of this setup is spooling so quick?

 

You have to keep in mind that this is a GT3574, and it has the exhaust housing machined to take a larger turbine wheel. While you can compare the results to a GT35, you can't compare them apples to apples on their exhaust A/Rs because they aren't the same turbo (not that end anyway).

 

I love the your idea of a divided wastegate manifold. Very simple yet very effective.
Barry

 

^+1