Hello Gentlemen,

I've asked this question of several and have created this post in hopes of coming to a great conclusion.

We are building up our widebody FC. 13BT motor. We're gonna be running a GT35/40 on there. What I'd like to know is how I can maximize the boost potential of this turbo. I assume that you don't want to run over 17-20psi on a 13BT.

This FC will have standalone and hope to god we will have it tuned by an expert, **** from Australia or Japan if I have to. We will not be running the car at such a boost I just want to know what I can do internally to run more boost. And how much boost those engine mods will allow me to run.

Next question is how to make that engine produce a lot more power without going beyond a street port. I would still like to drive this on the street here and there without my ears bleeding. IT already has a 90mm dp and exhaust. Should i run a differnt UIM or extrude hone the stock one. blah blah blah. Get everything Port matched???? I want the ultimate strong 13BT in this FC.

TIA for all your help,

Rishie

 

water injection ` and a big ic.... with the usual mods but as far as intake temps that should cover it... u have the standalone... and theoretically u can run 20 psi on pump gas... with a good ic... but id get water/ meth injection and jus tune it so it comes in at 15 psi... u should have no problems then

 

I have heard also water injection to run more boost safely(have never had it on anyones car i know personally though) but maybe you should read the thread on it and decide for yourself. Also you can use high compression rotors, but must have the housings shaved. You say you want the "ultimate strong 13bt" are you looking for reliability strength or kick everyones *** power strength?

 

Rishie, my streetport 13bt with FD housings, and rotors runs 26psi (with 103)no problem. It happens that I have a Baby turbo on it, so the #s won't knock anyones socks off, it's all tuner. I was running 15 psi, hooked the avcr up wrong, and saw 28-29psi twice. Called the tuner(not for hire ), and he said "no problem, the map is good to 30psi" This was M2s tuner when they ran IMSA.
Youve heard it before, it's all in the tuning... I run 25psi all the time now(race car). We will see what Chris comes up with, I may go T66 1.00 q trim. Carl Byck

 

Alcohol injection and plenty of fuel.

 

Water Injection can help you run upwards of 17 psi on pump gas safely but I think 20+ will require some GOOD tuning and race fuel, Ignition aplifier and some colder plugs. As well as adaquate intercooling fuel upgrades etc. A high flow pump and some big injectors, rising rate FPR and of course a serious clutch to hold it all. Axles that wont snap and a stonger Differential. Some motor mounts that wont tear apart.

 

i ran 19 psi of my rx6 b with a stock ic PUMP GAS FOOO..... lol so i serioulsy think that water injection with good tuning and a good fuel system is more than enuf as long as u have a good intercooler... mind u that all depends on how much over 20 psi u wanna go

 

ZoomZoom, Everything but the axles, now for a big *** turbo

 

Hey Rishie, 20psi should be no problem if you have your engine built right, have good engine support components and run conservative maps-

My boost creep was over 20psi by 4,000rpm on an untuned set-up and I never had any detonation, etc.

Use LOW compression ('87-88) rotors for higher boost applications as your turbo is MUCH more efficient at compressing the air mixture than your rotors AND has the benifit of the intercooler after it. Much cooler fuel and air charge in the engine being compressed means less chance of detonation!

Make sure your IC cools the intake charge very well, run your air temp/ ignition and air temp/ fuel correction factors conservative incase your intake temps do start to climb, run very rich, run even more rich in the boost levels above the desired boost- just incase, make sure your oil system cools very well- this is the only thing cooling the combustion surface of the rotors, make sure all your engine support systems are OVERKILL for the power level you want and have fun!

If you want any tips on working the intake system over- let me know- obviously, you have to do everything you mentioned and more for the "ultimate strong 13bt".

Spec 90 is LOUD! I think I will have to put a midsilencer in. I thought it was pretty damn loud and now I'm running my WG open and it is crazy- gotta fix that.

Ian
Have you heard a full Spec 90 yet? (Rarest rip-off style italics)

 

for 20psi on pump gas i'd say water injection. i run 15psi daily on my car on 93-94 octane pump gas. i will eventually get water injection and run 20psi on pump gas.....

i don't recommend low compression rotors they are like 3mm seals they are just a band aid!!!! if you tune it correctly you can get the same power on high compression rotors with less boost!!!!!

 

Hi Guys,

I'm also running a series 4 13bt engine(Mild Ported, w/2mm race seals), with a TO4E turbo, extra additional 4 injectors, Microtech MT-8. The car is being tunned now. I will be pushing up to 25psi, on race days and 18psi for street driving. Do you guys think these amount of boost is too high? Anyway, over here we use only 98octane petrol. Do I need to fit any thing else to prevent detonation? I just had 4 of my seals blown due to in-sufficient fueling, and we have just found out that it was only running on the standard 12A turbo fuel pump, have since upgraded to the mercedes ones ( Borsch Type).

 

water injection!

 

I'm in the same boat, I want to run more then the standard 15psi on pump. I was thinking 18 to 19 with water infection. Who here has been using this setup and what type or should I say who's is it (brand). How reliable is it and how much more power do you think you have gotten out of being able to run those few extra pounds of boost?

Thanks,

Joe

 

Vosko

I see high compression rotors on forced induction being like a band aid-

trying to get some tip in throttle response instead of concentrating on spooling that turbo to a higher psi just as reliably.

3mm seals *may* make your engine more resistant to detonation damage from poor tuning an so be a band aid.

Low comp rotors PREVENT detonation so you can up the boost w/ proper tuning and so are no more a band aid than proper tuning itself.

WTF, you recommend water injection to cool the mixture as it is compressed in a high compression rotor engine and call less mixture heating low compression rotors a band aid. I don't understand your logic- enlighten me!

 

here is how i see it. i can run 15psi on my high compression engine on pump gas and make 459rwhp peak. how much boost will it take to 459rwhp on pump gas on the same setup except low compression rotors? 18-20 psi??? how is that safer ??? isn't that a waste! that seems almost retarded to me. my point in using water injection is that you can take that same high compression setup that made 459 rwhp on pump gas and 500-520 rwhp @ 20psi on pump gas

 

A daily driver...

 

You guys keep talking about water injection, what is it and how does it work?

 

Water is a serious anit-detonate (cause it doesn't burn). It also aborbs a ton of energy/heat, and expands more than air. Basically it allows higher boost on the same octane gas without fear of detonation.

The water is injected into the intake stream using a seperate resivoir, pump, and nozzle. Where to best inject is somewhat up for debate.

 

i run 20psi no alcohol, no water injection etc... I run TEC2, great ignition acuracy, not bad.
I have ran 28psi a few times, but wasn't tuned right and runs way too rich... but its doable.

 

Possible, yes... but perhaps not the best or safest ( eh, throw caution to the wind I suppose). If you dump enough fuel in and/or retard the timing far enough 20psi is definately possible, but the thermal loads......

You ran 28psi on pump gas, are you insane ?!?

 

ajc13b ran like 30 psi on pump gas with zero timing ....

i would rather not risk damaging my very expensive engine

 

Sweet Guys. Thanks so much. I haven't checked back here.

GD, interested in tuning a FC??? hehe. I'm still debating what ECU to get. What would you reccommend.

Just so you guys know I have a street ported S5 motor that's been milled for 3mm seals. so that's already there. For that reason I don't want to bother changing the rotors out. What do you guys think???

I have an S4 I'm building for show and street as well, so I could swap the rotors. What would you do. I figure I'll need the 3mm seals on the widebody cause that's the one that will be under the microscope for tuning.

Thanks so much guys,

Rishie

I do have a contact for Aquamist. Dave V from Boosted Group. We've worked together on a couple projects and his ties with Aquamist are extremely tight. I was gonna go self mapping H2O injection as a fail safe measure regardless. They have some pretty cool units out there now.

 

the s5 rotors are better, they are lighter and the difference in compression small. I have run 1.67kg/cm2 bout 25psi on the stock s5 turbo at 10.0-1 afrs with about 15* timing and on 91 octane gas. My intake temps were about 130* F after the intercooler.

Don't build your system around water injection. It could fail itself and cost you your engine. I would just have it tuned by a professional..


You can get around 450rwhp with a streetport on a s5 block with a gt3540 at around 15psi.

The most I would safely run on 91 pump gas is 18psi

Your shop hasn't been moved right? I will be by this summer to order suspension and wheels/tires.

As for manifolds, I am machining a whole new setup. Individual throttle bodies, tuned length, i am looking to fatten my power band between 4000rpms and 6500rpms, running a 60-1. Maybe improve boost response too.

 

if you already have 3mm seals just keep em but 2mm will make more power

 

Suds, who do you know that has SAE dyno'd 450rwhp on a 3540? Let alone at 15psi? I have yet to see it with all the **** talking I do, you would think someone would post a dyno to shut me up, 1 year and counting, no such dyno. Carl Byck