Just wondering but what do most of you guys run as far as boost levels are concerned on the 1.8? I am wondering what is considered a safe range.

 

you can max out a stock turbo on the 1.8 and run enough fuel for most bnr stage 2/3's it just depends on how much pressure you are running the 4 720cc injectors, you could even use a 720/800-900 setup and runn a little overly rich on the top end. This of is assuming stock 8.5 cr rotors and 93 octane, anything else and you'll be looking at a rtek2.0 to adjust the timing.

 

According to Rtek7, the ECU will max @ .90 duty cycle. If you assume .70 BSFC (which is conservative), the 4X720cc (= ~70 lbs/hr @ 43 psi) will support 350-360 HP bursts.

The stock turbo/TMIC will not support this level of power. 1st of all the stock wastegate can not handle that much exhaust. Beyond ~260 HP, HKS steered you towards their turbo/FMIC upgrade. HKS (Stage 5 if I recall) claimed 350-360 HP @ 12.5-13 PSI boost. At those boost levels and 8.5 CR rotors, some smart folks will say 91 octane is fine.

The max boost obviously is dependent on your entire setup and octane of course.

 

Ok I see. I am looking to do 720cc primary and secondary injectors with an intake and 3" turboback and a fuel pump upgrade. The car will be running on 93 octane with the stock top mount intercooler and turbo.

 

That should be fine for what you have just be careful with boost creep.

 

Gotcha. How many pounds of boost would be save with this?

 

Well with a 3" turbo back it will probably creep from 6PSI to 10-12PSI fairly easy which is towards the top of its efficiency range.

I wouldn't run any more than that if it was me I would probably put a silencer in the exhaust and use a boost controller to keep boost levels manageable. Wastegate porting is also an option.

 

Ok cool thanks. Sorry I should have put that I already have a manual boost controller on the car to keep the boost levels where they should be.

 

Something to consider. I'm assuming your engine is not ported. If you absolutely have no plans of upgrading/changing anything on the intake side, the 1.7 should be just fine. Obviously you'll save on the injector purchase. If you decide to then put on the bigger turbo/FMIC down the road, you can then go right to the 2.1, move the 720 to the primary side and purchase bigger secondary injectors.

PS- the AFM to turbo stock coupler is extremely restrictive. If you were to attempt to run boost past 12psi w/an open exthaust, you will actually see the boost taper off. This is from personal experience. In a way it's a boost limiter.

 

Something to consider. I'm assuming your engine is not ported. If you absolutely have no plans of upgrading/changing anything on the intake side, the 1.7 should be just fine. Obviously you'll save on the injector purchase. If you decide to then put on the bigger turbo/FMIC down the road, you can then go right to the 2.1, move the 720 to the primary side and purchase bigger secondary injectors.

PS- the AFM to turbo stock coupler gets extremely restrictive as the engine's air demand increase. If you were to attempt to run boost past 12psi w/an open exthaust, you will actually see the boost taper off. This is from personal experience. In a way it's a boost limiter.

 

I plan on changing some things on the intake side pretty soon haha. That why I was thinking of going with the 1.8. The intake on mine is actually pipe and all not just a cone filter on the AFM if that is what you mean.

 

I have a 1.8 w/720's and Im still showing lean at 12-13psi. I know this doesnt sound right so Im losing faith in my Innovate wideband. Im going to re-calibrate it and I picked up an SAFC 2 to fatten things up a bit more if needed. I cant stay in the throttle in 3rd gear or higher. Kinda sucks.

Streetport
3" exhaust
FMIC
pump...and so on

 

Does kinda of suck. That's not something I'm looking forward to. I haven't had the chance to get on it because of some light throttle hesitation issues (I have a thread up on this). What's your fuel pressure when you start running lean? At what RPM? Is your engine tight? i.e., good compression/vacuum? If the engine is sound (hence a BSFC in the low end), I wouldn't expect it to run lean before redline under full load, 5th gear.

P.S. - Where did you get your injectors from? Were they new?

 

Im not sure of the fuel pressure. 1000 miles on the rebuild and it pulls about 17" of vaccum at idle. My injectors are Greddy and are new in the secondaries and used in the primary.

I think part of my problem is voltage at my pump. Sometimes Ill hear it whining and other times I cant hear it at all. A re-wire is on my "to do" list. Fuel filter and and post filter fuel lines are all new.

I put my stock TID back on to try and choke it down a bit but it didnt really help. The streetport just moves to much air. I still get boost creep even with a ported 28mm wastegate.

What I need is a BNR and a Haltech.

 

We have found if you have ANY port, you will need fuel control for the midrange.

 

Hey Chatchie,

I am in the progress of saving to get my 13bt motor rebuilt soon with a mild street port. The setup I plan to run is basically the similar to yours. Mild street port, BNR stage 3, FMIC, 720 inj, fuel pump, and RB full turbo back exhaust. Will the rtek 2.1 at stock setup be good enough for motor break in? Or am I gonna have to have it tuned just to break it in? Just wondering if I am gonna have to save even more for a Haltech to be able to run this setup. If I do, I may hold off on the street port as I hear its a pain to tune with an Rtek setup and I won't have enough for the Haltech setup.

 

I broke my street port in on the stock ECU and 4x550. It ran/idled fine.

When you get your Rtek back from Digital Tuning it has the factory map there, it will run like stock. Youll just have to set your injector presets.

 

Thanks for the info man! Always good to hear comments from someone who is running a setup you plan to use.

 

If I were to run the 1.7 with the 720cc secondaries what would be a safe amount of boost I could run. Car has an upgraded fuel pump and I plan on getting the injectors and rtek, 3" turbo back and an intake, stock turbo and intercooler.

 

12 psi

 

Is that the max the stock turbo could run or just the max with that setup?

 

Pretty much both. The stock turbo will run higher but you are way out of it's efficiency zone so you are heating the air more than you are compressing and so it's more prone to detonation.

 

Ok. Thanks for the info. I just wanted to be sure.

 

like some have already said, port your waste gate, the stock wastegate is around 11 mm, i went to a 32 mm waste gate, and can't run anything less then 11 psi. only at 11 does it equal out to fully open the waste gate, then it still creeps to 13-14 from there on cold nights.