Thread: 4BD1T Turbo Sizing and Performance Prediction.

Originally Posted by Dougal

Best of the Holsets is the HE221. It's actually an MHI turbo with a special compressor wheel, the closest MHI model is the TD04HL-19T. You can roll-you-own with any TD04HL turbo and buying a 19T compressor wheel and cover. Some clearancing of the core is likely to fit the larger wheel though.

Yeah billet compressor wheel version of a HX27. would be better in the low end also with still a good amount of airflow. personally id rather the 30 on one though.

TD04-19T would be interesting but personally the cost of a 15T being up around $8-900 plus 19T conversion work on top of that probly $400 more, Value for money is always in the Holsets i believe,especially when a brand newie can be had for $800 odd AUD its the way to go

A HE351 would be good to see. Billet wheel also, same trims as a HX35 but with a smaller 9cm rear housing. Comes as a VG unit too

Originally Posted by chang

A HE351 would be good to see. Billet wheel also, same trims as a HX35 but with a smaller 9cm rear housing. Comes as a VG unit too

They are all far too large. Designed to work on a 5.9-6.7 litre engine. On an engine 2/3 the capacity they are in surge.

See the first pages of this thread for compressor maps that work.

[QUOTE=Dougal;1899502]They are all far too large. Designed to work on a 5.9-6.7 litre engine. On an engine 2/3 the capacity they are in surge.

See the first pages of this thread for compressor maps that work.[/QUOTE

3076R with an antisurge comp housing would take care of that

Originally Posted by chang

3076R with an antisurge comp housing would take care of that

Surge slots in the housing etc do damp out the pressure pulses from surge, preventing the damage. But you are still running a turbo in the least efficient part of it's compressor map. This means your boost is hotter, boost is lower, your drive pressures are higher, EGT is higher and engine power is lower than they are be with the same fuel on the right sized turbo.

Put simply, there is no good reason to fit an oversize turbo and many very good reasons not to

The GTX3071R is mapping out only marginally better than the HX35 (sorry Cheif). The GT3076 is worse.

My stir up plan backfired

Anyway on a serious note, has anyone clocked up real-time data using a HX30 on a 4BD that you know of?? Ive been trolling the interwebs trying to find such info where someone has used a data log guage setup on one with no luck. I just believe it would be quite a surprising unit, (yes with a sacrifice down low but nothing dramatic) & give a little more room to tweak.

Originally Posted by chang

My stir up plan backfired

Anyway on a serious note, has anyone clocked up real-time data using a HX30 on a 4BD that you know of?? Ive been trolling the interwebs trying to find such info where someone has used a data log guage setup on one with no luck. I just believe it would be quite a surprising unit, (yes with a sacrifice down low but nothing dramatic) & give a little more room to tweak.

Lots of guys have run HX30's on 4BT's in the states. The HE221 is getting universally better reviews though. I think it's simply a more advanced turbine and compressor wheel.

Right.

As mentioned earlier, I had the wrong units on the fuelling. It was labelled cc/1000 shots, but was actually grams/1000 shots which is 15% lower than it should have been.
Instead of cropping the fuel at 140cc, it was 140g which is ~18% too high.
Torque graphs follow fuelling graphs, the maximum torque is now ~630Nm. Not the ~750Nm reported earlier.

The graphs have been corrected, the new ones are copied in here:

24psi, no intercooler:


24 psi intercooled. This now reaches the 140cc fuel limit, 24psi isn't required at such low revs, I have shown it with a leaner A/F ratio in parts to give a smooth boost curve:


Maximum fuel to 3,600rpm, this doubles the original engine power and torque:


The Holset HE221 and MHI TD04HL-19T are the only turbos I've mapped out which cover the maximum fuel to 3,600rpm scenario nicely. Borg Warner will, but I haven't re-run those numbers yet.