Zero R

iTrader: (1)

Damian also runs a larger housing than Rich does (that is what he requested)and seeing that he runs lower levels of boost the turbo will feel lazy especially between shifts.

The biggest thing that will effect your boost curve is going to be your boost level. If your riding around in cars with 35R's and they are all on pump gas and running around 15-16psi. They will certainly spool slower than if they were running 18-20psi. We have noticed as little as 3psi can make a huge difference in the way a turbo responds. Even between shifts can be effected by that same 3psi.

The next biggest thing will be resistance to the wheels either in the exhaust or in the compressor side. A well thought out and setup IC system will seriously make a difference over a slap on kit. (problem is most want 500hp for $500, oh and please do that on 91 pump ) So asking them to spend the money for a custom spec unit is hard.

I have seen 35R's hit 1bar by as little 3300rpm at 20psi. On most cars that we do or that have come in, it is usually 1bar at around 3600-3800rpm at 15psi. With some as late as 4200rpm. That would be pretty accurate when comparing with your boost curve of 15psi by 3600rpm.

The T4 divided 1.0's see better response than the T3 1.06's as well.

It is impossible to say because car A does this with X setup on #1 dyno, car B should do the same with Y setup on #2 dyno.

It is very fair to say 35R based FD's will be your best all round fun street car. They work well on stock ported motors and street ported motors. They give excellent response without dropping of up top in divided T4 form.

Rx-7Addict

iTrader: (2)

I have a T04R with a smaller, .84 hotside , large streetport and 3" exhaust. Open 44mm tial wastegate.

The car makes 15psi by 3800 rpm, and has decent power anywhere above 3000-3500rpm. The car is sluggish below 2500rpm, but that is not an issue for me. Probably not much worse than twin turbos. If I remember, the car stock is still pretty sluggish at very low rpm. I have no problem keeping it above that or being patient, since if I am in traffic I cant really drive fast anyways.

The T04Z should spool a little quicker, due to BB

The car is not my daily driver, but could be, and I drive it quite a bit if the weather is nice and its running, although the 6 puck clutch is a bit of a pain.

edit: I would get the T04Z over the GT35R. Theres a reason the GT35R spools so quick -- its a small turbo!

PandazRx-7

iTrader: (18)

I have a 500R with 1.06, 3" exhaust with RB duals, street port, monster V-mount, wastegate on spring only.

When I stab it in 4th gear at 3,000rpm, I see instant 8psi which than shoots to 15psi by 3,500rpm. My dyno sheet tells me I get 200ft/lbs of torque by 3,600rpm.

BEX

i appreciate the suggestion of the gt35r. if early boost and pure streetablity and fun on the streets was my primary goal then i'd go with the 35r.

BUT, i'm not asking for the quickest spooling non choking at high rpms turbo. i am going to be making a t04z setup for my particular app.

i'm aiming to make 325-350 whp at 10psi. of all the compressor charts for different turbos the t04z is near its peak efficiency at 10psi around ~360 lb/min airflow.

based on the equations i've dug up, a decent tune 360 lb/min airflow translates to the ball park of 320-350 whp on a 13b at indiana summer temps and elevation.

therefore the t04z will be my turbo of choice. whether it is streetable or not is 1. a matter of opinion (and i am getting some very promising opinions) 2. not the primary goal but possibly a perk.

i was just hoping that the streetablity factor existed with this particular turbo on a decent tune, and it seems so from the responses i'm reading.. thanks everyone!

i got to see a t-88 half bridge this weekend and the guy didn't seem to have too much trouble getting it around at street speeds. however he thought is was to loud to be a dd. but my younger brother's corolla has corroded manifold and is just as loud and he drives it around as his dd everywhere.

i've read on this forum there is a guy who road races a t04z at 10psi around 350 whp with an amemiya kit and he puts down decent lap times out there.. so if it works well for him then that'll be the direction i go.

from the sounds of it a gt35r give good response but wouldn't be a good road racing turbo because it's low psi comp efficiency is too low in the airflow range and its comp efficiency at high psi (above 14 psi) is in the right airflow range for me

but the anything above 12psi (even at 85% compressor efficiency) is just too hot for the intake charge and intercooler heatsoak conditions and engine bay when continuous lapping. so i must go with a larger turbo for 325-350 whp.

Rotary4tw

iTrader: (3)

You should ask him about the boost he was running at MAM earlier in the month! It was quite the opposite of lazy, if only for a few seconds. Guess the 500r caught wind of the 200k GT3 cup car that was out there with him.

I have not read this before. Wouldn't the two systems... one running 15psi and one running 25psi, function exactly the same way, until you reached the springs? (Assuming 1bar springs) It doesn't make much sense to me in concept, but I trust your experiences on the dyno over my ability to understand thermodynamics.

Are you talking just about volume/size of the intake track aka pressure drop? Or are there other variables?

.

I have been really impressed with the GT-35r and the 500r from both GooRoo's and Damian's setups. If I don't fall in love with the rx6 at 17psi this season, your products are at the top of a short list for an upgrade!

Hey Rich, would love to see your dyno sheet showing your 500r hitting full boost at 3600-3800 rpm. Talk about an argument for going 4"!

dpf22

There are other ways to see when turbo's spool and otherwise reach positive pressure. Most of the people with these turbos are running a standalone. Thusly a simple datalog showing pressure/vacuum vs rpm and throttle position is all we need. Screenshots anyone????


dpf22