ISIS T25/T28 replacement turbo v. S15 T28. Input appreciated!

[TAP240]

Originally Posted by ultimateirving

I went directly from t28 to rs3871, it is direct replacement, i do run it without a retune currently but i run rich so i could benefit highly.

what does your air fuel read in WOT?

[ultimateirving]

10.5! with e85 and 850cc injectors, i have a mail tune tho. need some local dyno work done

[TAP240]

Originally Posted by ultimateirving

10.5! with e85 and 850cc injectors, i have a mail tune tho. need some local dyno work done

damn..that's not as rich as I though you were gonna say, but that is pretty rich. My tune right now, with my previous bb t28 was at about 10.8-11.0 during the hot parts of the day, and when it cools down at night it'll go to around 11.3-11.5 (which is ideal). Tuned with Nistune and AEM tru boost (stock tune, 12lb tune, and 17lb tune). I've got brian crower cams (not sure if that has a major effect), 550cc injectors, wally 255 fuel pump...if I were to install the RS38..what do you think the results would look like (and yes, I know, "every car is different" lol, but based on your experiences with this turbo).

[TAP240]

Originally Posted by TAP240

damn..that's not as rich as I though you were gonna say, but that is pretty rich. My tune right now, with my previous bb t28 was at about 10.8-11.0 during the hot parts of the day, and when it cools down at night it'll go to around 11.3-11.5 (which is ideal). Tuned with Nistune and AEM tru boost (stock tune, 12lb tune, and 17lb tune). I've got brian crower cams (not sure if that has a major effect), 550cc injectors, wally 255 fuel pump...if I were to install the RS38..what do you think the results would look like (and yes, I know, "every car is different" lol, but based on your experiences with this turbo).

My mistake, I have 750cc injectors, not 550

[stilmissmysti]

Originally Posted by ultimateirving

I went directly from t28 to rs3871, it is direct replacement, i do run it without a retune currently but i run rich so i could benefit highly.

Originally Posted by ultimateirving

10.5! with e85 and 850cc injectors, i have a mail tune tho. need some local dyno work done

10.5 is lean on e85

Fuel AFRst FARst Equivalence Ratio Lambda
Gasoline stoichiometric 14.7 0.068 1 1
Gasoline max power rich 12.5 0.08 1.176 0.8503
Gasoline max power lean 13.23 0.0755 1.111 0.900
E10 stoichiometric 14.0 - 14.1 ? ?
E85 stoichiometric 9.765 0.10235 1 1
E85 max power rich 6.975 0.1434 1.40 0.7143
E85 max power lean 8.4687 0.118 1.153 0.8673
E100 stoichiometric 9.0078 0.111 1 1
E100 max power rich 6.429 0.155 1.4 0.714
E100 max power lean 7.8 0.128 1.15 0.870


that means you should IDLE and regular driving should be around 9.8 (idle could go much lower like 13's) and WOT should be in the high 6's and any boost should be in the 8.5 range


E-85 pulls more heat than gas and will run leaner (in lambada standards) but you are far short of maximizing your set up
__________________

[Croustibat]

Originally Posted by stilmissmysti

10.5 is lean on e85

Fuel AFRst FARst Equivalence Ratio Lambda
Gasoline stoichiometric 14.7 0.068 1 1
Gasoline max power rich 12.5 0.08 1.176 0.8503
Gasoline max power lean 13.23 0.0755 1.111 0.900
E10 stoichiometric 14.0 - 14.1 ? ?
E85 stoichiometric 9.765 0.10235 1 1
E85 max power rich 6.975 0.1434 1.40 0.7143
E85 max power lean 8.4687 0.118 1.153 0.8673
E100 stoichiometric 9.0078 0.111 1 1
E100 max power rich 6.429 0.155 1.4 0.714
E100 max power lean 7.8 0.128 1.15 0.870


that means you should IDLE and regular driving should be around 9.8 (idle could go much lower like 13's) and WOT should be in the high 6's and any boost should be in the 8.5 range


E-85 pulls more heat than gas and will run leaner (in lambada standards) but you are far short of maximizing your set up
__________________

If you ever had used E85 and a wideband, you would know gauges displays "measured lambda x 14.7", which means stoich will show 14.7, no matter what fuel it is.

10.5 on a gauge display for e85 is quite rich, i usually get good results with 12:1, bit more with 11:1, but richer does not yield anything.

[stilmissmysti]

Originally Posted by Croustibat

If you ever had used E85 and a wideband, you would know gauges displays "measured lambda x 14.7", which means stoich will show 14.7, no matter what fuel it is.

10.5 on a gauge display for e85 is quite rich, i usually get good results with 12:1, bit more with 11:1, but richer does not yield anything.

Thank you for clearing that up for me I have never ran it in any of my cars, but I'm a chemist by trade so it seemed a bit off to me

[smink]

The lag isnt terrible. Im hitting full boost by 3500ish. The Ka deffinately spools it quicker, granted its a larger displacement. For the most part im satisfied with the turbo for dd purposes.

[TAP240]

Originally Posted by smink

The lag isnt terrible. Im hitting full boost by 3500ish. The Ka deffinately spools it quicker, granted its a larger displacement. For the most part im satisfied with the turbo for dd purposes.

And that's all I'll be using the turbo for, daily driving...I was at full boost with my t28 around the same time (I'd say about 3300ish).