Hi I was wondering if any one out there can share there info on when to expect full boost to come online on a to4z turbo running on a street port.
Thanks

 

From what I have seen from about 4-5,000rpm depending on the rest of the set-up.

 

Ok so how much does a/r effect spool up, lets say 1.0 to 1.15 is that like a -5% difference or more or less.
Thanks

 

I would say around ~500rpm spool difference between a 1.00 and 1.15 T4 exhaust housing if you have a 3" plus straight through exhaust.

So, around 4,500 to 5,500rpm full boost on 1.15AR T04Z with streetport.

A port with more overlap (semi p-port or bridge) will spool the turbo a bit sooner, but then you definitely would want the 1.15 or 1.32AR exhaust housing for the track.

Then you are back to same spool range, but with torque extended past 8,000rpm.

 

So what a/r would you recommend for a street car with street ports, BTW I do want to make around 450hp

 

if you have not committed to the TO4Z i suggest other options. the TO4Z is a 500+ hp turbo w a 7 sq inch average area compressor w a slower spooling 63 trim. (see my sticky thread Turbo Comparisons)

some items are best bought new and IMO a turbo fits into that category.

the BW S300 series is value priced, OE build quality, and the 177272 and 177280 (90 degree outlet) should work well but might be a few ponies short of 450. rotary friendly w a larger turbine wheel than the TO4Z.

Howard

 

For the price of a real T04Z (HKS) you could pick up an EFR 8374 or 9180 and have incredible spool. These are the turbos used in Indy cars since '11 and are very quickly replacing Garrett GT turbos in all motorsports.

I would choose the EFR 8374 for 450rwhp. You will get full boost 3,500 to 4,000rpm.

I would choose the EFR9180 if I wanted 450rwhp with room to grow and I could tolerate a little less response. No charts yet, but expect full boost 4,000 to 4,500rpm.

 

I have the HKS To4z kit with the small A/R (0.84 i think), not the 1.00 A/R, tuned up to 1.3 bar boost..full boost is at 3900 rpm ..and I've been thinking of changing to the new EFR line.. should i go for the 8374 or the 9180? A/R ? boost would be the same, 1.3 bar.. estimated gains in terms of spooling and power compared to my kit?
thanks,
George

 

Just got rid of my T04z but I had 20lbs of boat sounds 4200rpm of my memory serves me right. Street ported motor

 

Auto correct sucks, sorry. 20lbs of boost around 4200rpm

 

If Howard Coleman hurries up, then I'd bet that you'll see EFR 9180 will out flow and out spool T04Z all day.. Light years away in terms of tech... on paper... Hurry up Howard!