BNR Turbos, sheets and engine spec plz!

[FerociousP]

Originally Posted by RotaryDiagnostics

Here's a sheet from a recent dyno run. Car has a BNR Stage 1 turbo, 750cc RC secondaries, 3" RB REV-II turbo-back exhaust system, Supra TT fuel pump, Bonez intake, and Apexi S-AFC II tuning.

Tried the Rtek 1.7 chip, but the tuner could not get a safe AFR, so had to revert to a stock ECU and rely on the S-AFC for tuning. Engine runs awesome on the track. It does have an intermittent starting problem and a bit of a rough idle, which I will address during the off season. May try chipping a different ECU.

I have the same setup just with a stock turbo and no S-AFC. What issues did you attribute to the RTEK 1.7 that were fixed with the stock ecu? or was it just you couldn't tune with it?

[RotaryDiagnostics]

Originally Posted by JerryLH3

Are you running the stock TMIC? Just curious, as it looks like your setup will be similar to mine in many regards once I get to the performance stuff after I finish the paint and body.

Yup, the stock IC.

[RotaryDiagnostics]

Originally Posted by FerociousP

I have the same setup just with a stock turbo and no S-AFC. What issues did you attribute to the RTEK 1.7 that were fixed with the stock ecu? or was it just you couldn't tune with it?

The AFRs were going way too lean when attempting to tune on the chassis dyno with the Rtek-chipped ECU. Not sure if the ECU I had the chip installed in was defective. Sent the unit back to Digital Tuning to verify that their chip was good and they indicated it was good. Sent the RC injectors back to RC Eng. to verify they were good and they were good. I reinstalled the original ECU and had the car tuned with the S-AFCII. Car tuned with a safe AFR and it runs great on the track. Needs a bit of tuning at low/zero throttle settings I think 'cause it is a bit hard starting and needs to be helped with the throttle once it starts until it runs for a minute or so.

Definitely put the car on the dyno before you run it too hard with the mods. Rtek 1.7 purports to be mapped to 720cc or so secondaries, but like Reagan used to say, trust but verify.

[FerociousP]

Originally Posted by RotaryDiagnostics

The AFRs were going way too lean when attempting to tune on the chassis dyno with the Rtek-chipped ECU. Not sure if the ECU I had the chip installed in was defective. Sent the unit back to Digital Tuning to verify that their chip was good and they indicated it was good. Sent the RC injectors back to RC Eng. to verify they were good and they were good. I reinstalled the original ECU and had the car tuned with the S-AFCII. Car tuned with a safe AFR and it runs great on the track. Needs a bit of tuning at low/zero throttle settings I think 'cause it is a bit hard starting and needs to be helped with the throttle once it starts until it runs for a minute or so.

Definitely put the car on the dyno before you run it too hard with the mods. Rtek 1.7 purports to be mapped to 720cc or so secondaries, but like Reagan used to say, trust but verify.

my setup:
FMIC
no emissions
stock turbo
cleaned 550s, new RC750s
Rtek 1.7 keeping mop
old school RB full T2 exhaust (large diameter, 1pc DP/presilencer to catback)
FD fuel pump (Denso's aftermarket replacement for a FD and supraTT pump are the same part#)
Innovate WB


Thanks for the info. I've got no emissions or AWS but only need to hold the throttle for just a second or two and then it idle's fine. I've ran mine at an autocross road course and it ran well. What were the AFRs before you made the switch? With a FMIC mine does well (in the 11s) in 3rd gear but my boost bleeds down to about 8psi. In 4th (interstate) it will creep past 12psi to 13,14,15 and the AFRs ride quickly. I once saw a 13AFR but backed off quickly. Luckily, I don't have the need for full boost in 4th gear so the problem doesn't present itself... I just have to remember.

Next step was going to be either port the wastegate or go BNR stage1, so its good to know what people have tried. I just want to know if the RTEK 1.7 is going to be enough ahead of time and not pop the motor.

[RotaryDiagnostics]

Here's the sheet showing the AFRs getting very close to 14:1. Tuner shut it down at that point and we went to Plan B, which was, as I said earlier, to replace the Rtek-chipped ECU with a stock unit and using the S-AFCII for tuning.

If you have not had your car on a dyno, or using some other way, to verify safe AFRs, I would recommend that you do that before pushing the revs.

[barnett87rx7]

my setup:
bnr stage 4
megasquirt
walbro 255
custom v-mount
stock 550 primaries
1600 secondaries
2.5" exhaust
stock ports
16 psi

making 385-400 hp

300hp has been made with the stage 1 your power all depends on how good your tune is