The definitive spoolup thread
 

I see so many people ask, " so when do you hit full boost, when do you start spooling?" That question is so commonly asked, so why not make a thread where we tell what turbo we have and where it spools. This will clarify it for a lot of people.

Turbo : GT3271 .78a/r hotside -- .50 a/r coldside
Manifold/DP : Log manifold w/ 2.5in DP
Exhaust : 3" enthuza w/ thermal muffler

I start making positive pressure around 3000rpm and have 7psi by 3500rpm. By the time Im at 3700rpm it starts really pulling and by 4300rpm or so in 3rd gear I have a full 16psi.

3000rpm = 1-2psi
3500rpm = 7psi
3700rpm = 10psi
3900rpm = 12psi
4100rpm = 14psi
4300rpm = 16-17psi

Thats on a 1.8L bored .40 over with a ported 95 head. Lets hear it from others.

my small 16g on a stock 1.6
1 psi 2000 rpm pulls ok
5 psi 3000 rpm pulls real nice
12psi 3900 rpm your going going gone
15 psi 4200 rpm damn safc.
20 psi 4700 rpm didnt stay there long. No cat now but cat didnt effect me to much as i had a high flow before, helped up top though.

Turbo: Turbonetics t3/t04e, 57trim 50AR, Stage3 48AR, oil only, mbc
Manifold: SSA stainless tubular for 1.8 Miata
Exhaust: OE internal wg w/2.5" exit to full 3" exhaust no bends (3" downpipe, universal cat, chambered muff).
Engine: Stock 2.0 FE-DOHC (1.6 tb, 1.6 Link ecu- needs more tuning- very fat up top)

This is what I'm seeing after two 12psi (peak) runs (3rd gear, 4.10), with one tuning adjustment in between.

1800rpm = boost onset
2900rpm = 3psi
3500rpm = 6psi
3900rpm = 9psi
4400rpm = 12psi

Turbo: T3 Super 60, .42 / .48
Manifold: BEGI (directed pulse model)
Exhaust: BEGi Downpie 2.5"-2.75", High-Flow Cat 2.5", Borla Exhaust 2.25"
Engine: 1.6

1800rpm = boost onset
2900rpm = 3psi
3500rpm = 6psi
3800rpm = 10psi

man our setups are a lot more similar than I thought. Our spoolup is nearly identical.

GReddy 15G at dyno 9/23/06

3000 rpm start of spool
3150 rpm 3psi
3450 rpm 6psi
3800 rpm 9psi
4000 rpm 12psi
4100 rpm 15psi
4350 rpm 18psi

and then it started dropping off as rpm increased. These were from a log on Zeitronix

<2500 RPM onset of spool
2500 RPM 1-3psi
3000 RPM 5-6psi
3500 RPM 7-8psi
3500-6000 RPM 7-8psi
6000 RPM + creeps up to nearly 9psi

Nissan SR20DET "red top" T25, not sure of the exact number right now.

Current Style BEGI cast manifold, BEGI series Z (mild steel, integrated wastegate path) Downpipe, Stock exhaust, no ic, Emanage on ignition only, BEGI FMU. Wastegate actuator sets boost to 7 psi max.

Start acelerating at 1500 rpm in fourth gear.

1600 RPM Boost onset.
1800 RPM 1-2psi
2500 RPM 4-5psi
3000 RPM 6-7psi
3500 RPM probably much more than the actuator is allowing.
Someplace around 6k RPM boost starts to drop a little, probably due to wastegate creep.

get rid of that stock exhaust, thats causing a huge restriction.

why are brian and older guy so late with spool? on such small turbos"

OEM Subaru IHI Vf10 Turbo with a 15R turbine housing and 52mm comp wheel. 1.5" log manifold ....2.5" DP and exhaust.
Hitting positive boost at 1900rpm
5 psi at 2400 rpm
8 psi at 3100 rpm.
Holds all the way to redline...

looks as if itll hit 10 psi at 3400

Dyno plot:
http://www.cardomain.com/ride/264041/6

Could be the way the tech added the load to the dyno or the way the dyno adds load by itself. I checked a datalog of a run I made on the road two days afterward and got these figures:

Start 2300rpm
3 psi 2500rpm
6 psi 3100rpm
9 psi 3600rpm
12psi 3900rpm

Couldn't go further 'cause I ran out of road. I thought the dyno would add more load than the hills around here.

Well, my turbine is a TD04, but my compressor is a little smaller than a Greddy turbo's, plus I have big runners in my manifold.

I'm probably even being a little conservative on the spool estimates. If I did it over, I'd have just built a log mani. and used a smaller turbo, but I got this turbo free, so who am I to complain.

well according to my last dyno chart I've got 6psi rock solid from exactly 3000rpm all the way to fuel cut ~7000rpm. That was in 5th gear on a dyno dynamics dyno and I'm just reading the pressure off the chart I've got so I can't really say where exactly boost onset really is but it looks pretty close to 1550rpm as far as I can tell.

oh yeah, this is a GT2560 at 6psi on a FM voodoo kit with no IC and stock exhaust.

1.8l ?

yep 99

oh yeah i forgot you have a smaller compressor for some reason i always though you had a smaller turbine on a greddy coldside. As long as it is fun it doesn't matter

this thread is great... This thread will help me see what set ups are building boost earlier and more progessively. I drove a friends Greddy and i didn't like how it seemed like a light switch, slow then BAM!

Greddy 15g, stock greddy DP and mufflerless stock 93 piping, pretty much stock greddy kit.

0 psi to 3100
2 psi @ 3500
5 psi @ 3800

5 psi is max right now :(

Stock exhaust?