91oct, 34mm flapper, higher boost, boost creep etc...

[yellowkyd278]

Hey everyone,

Currently Running:
evo3 16g w/ 34mm flapper (possibly a gt30r later on)
660cc & 255lph (bigger injectors will come if new turbo)
stock 2g ported exhaust mani
rnr o2 elim 3" full exhaust
dsmlink
dejon dual stage MBC

I'm currently running w/ the 34mm flapper on my evo316g and am reaching the point where I'll be going over the 22+ psi mark within the next few months. I've heard the flapper can possibly blow open at higher pressures and have a few concerns.

note: I currently do have some creep @ WOT and espeically at higher speeds (@ 120 mph+ WOT the seems to go up w/ no end in sight)

1. How will I know when the flapper opens? Will the boost pressure just drop suddenly?

2. A Tial external will rid of all boost creep problems correct?

3. I get the feeling the external cannot be mounted on the stock exhaust mani so would I need to pick up an evo3 exhaust mani if this is the case? Will the evo3 mani fit a GT30R in the event that I choose to upgrade or would I have to pick up another mani?

4. For the evo3 mani, is it possible to buy one with the flange for the Tial already created in the proper place on the mani? Who sells it and for how much?

5. Is the flange for the 38mm - 45mm Tial externals all the same?

6. For those living in the NorCal Bay Area, does anyone know off the top of their heads if FFTec will be able to weld the flapper door on my current 16g shut? If not, know of any shops that are capable of doing it correctly?

7. I've heard mounting the external on the DP is also an option but does anyone know if the RNR o2 elim exhaust system is weldable? If possible, I know its cheaper than buying a new mani and mounting but how much worse will it perform? If the difference is not noticible w/ the 16g, will I be able to tell on the gt30r?

8. CA only gets 91 oct. Properly tuned w/ a FMIC and all other proper support, what is the recommended safe boost level? What about on 110 race gas (also tuned accordingly)

9. Is the Tial 38mm sufficient for both the evo316g and the gt30r?


that was a mouthful...

If the answers could be numbered according to the questions they're answering that'd be awesome!

Thanks!

 

[Jetblack]

Quest. 1: Just like all the other EvoIII owners with creep issues had to do, go ahead and port it out and be done with it, it actually works I know. You won't know when your wastegate opens unless you have an O2 dump where you'll hear it loud and clear but other than that since you have creep issues it'll be hard to tell. you'll know it's working after the creep is gone and your boost stays where it's supposed to. My $ .02.

 

[fourreGsixty3]

1. How will I know when the flapper opens? Will the boost pressure just drop suddenly?

The flapper is open while its creeping, but the EGs cant move quick enough for then to exit to the o2 housing, that is why porting the o2, and hot side of the turbo helps eliviate boost creep.No it will level out.

A Tial external will rid of all boost creep problems correct?

Yes, but you will need the proper spring rates.

I get the feeling the external cannot be mounted on the stock exhaust mani so would I need to pick up an evo3 exhaust mani if this is the case? Will the evo3 mani fit a GT30R in the event that I choose to upgrade or would I have to pick up another mani?

You can have a shop make a flange on the stocker, SBR has an external mount flange on 2g exhaust manifold. You will need which ever manifold you choose to have the same style flange as the GT30R, SBR can put almost any flange on any manifold.

Is the flange for the 38mm - 45mm Tial externals all the same?

No they are different, for example the larger WGs have v-band's.

For those living in the NorCal Bay Area, does anyone know off the top of their heads if FFTec will be able to weld the flapper door on my current 16g shut? If not, know of any shops that are capable of doing it correctly?

Any competant shop can weld it shut.

I've heard mounting the external on the DP is also an option but does anyone know if the RNR o2 elim exhaust system is weldable? If possible, I know its cheaper than buying a new mani and mounting but how much worse will it perform? If the difference is not noticible w/ the 16g, will I be able to tell on the gt30r?

It is actually for the o2 housings, this isnt a great thing to go, the best route would be doing the wg on the manifold, the SBR o2 housing wg is for internally gated turbo's such as 14B and 16Gs, of course any turbo can be internally gated but its pointless when pushing high psi, also with this wg set-up you have to remove the flapper in the internal gate, so whats the point of getting it internally gated to pull the flapper. If you were just keeping the 16G or had a 14B with high boost, the SBR wg on the o2 housing is a good idea.

CA only gets 91 oct. Properly tuned w/ a FMIC and all other proper support, what is the recommended safe boost level? What about on 110 race gas (also tuned accordingly)

the tune will change with timing and af ratio depending on what you are using. I would say get a meth injection kit(it ups the pump octane, I have 93 octane here in Connecticut, and Im going with a meth injection, I should get 98-103 octane with 93 and meth injection, tune it once for this octane level, and you can run high boost, the boost level depends on octane rating and the CR of your pistons, also your injectors will need to be changed due to crapy 91 octane heres an injector link>>>http://www.roadraceengineering.com/eclfuel.htm, just scroll down a little bit.

Is the Tial 38mm sufficient for both the evo316g and the gt30r?

Yes it will be fine for both.
Hope that helps, sorry for the long post,

Dustin

 

[eclipsegsx1736]

As for the octane issue, 91 plain sucks, and race gas in CA is hard to come by for anything close to resembling a reasonable price (read: $7.50 for 100 octane..) The best option for us IMO is alcohol injection. I could only run about 18-19 psi on 91 pump, no matter how I tuned. Water injection helped, I could run about 20 psi with more timing, but pure denatured really did the trick..I can run over 23 psi (haven't spent much time over 23 yet, just starting to tune), and I can get more timing than I did at 18-19...I say it's definitely worth it. You'll be buying $10/gallon jugs of alcohol, but they last a while. I basically spent most of my gas tanks at WOT tuning the hell out of this thing, and still this gallon jug lasted at least 4 tanks of gas..and remember, it'll last much longer than that if you're not at WOT all the time. I got the coolingmist kit, which I really like, I just turned up the pump pressure a little to get a little more alky coming out of the injector, stuff really works.

 

[donmagicjuan]

First of all, that was a very nice response, Dustin. It must have taken a while to write up.

Generally, you have three options when it comes to boost creep. You can 1) port the hell out of your turbine housing, 2) go with an external WG, or 3) install the supporting mods to permit running higher boost. I chose option #3 with pump gas and water/meth injection. As the others have stated, the results are well worth it. I'm able to run 26 psi with 19-20 degrees of peak timing on my setup.

I'm also running a 34mm flapper on my EvoIII 16G. As a reference, my boost stays steady till about 5500 RPM, after which it slowly decays from 26 psi to about 22-23 psi at redline.

 

[fourreGsixty3]

Thanks Don. Yes, it did take a decent amount of time to do it, but I figure awnser all his questions in one post, but also whats time when your at work getting paid I love getting paid at work and comming on here to help out. I see we are all thinking on the same page with meth injection to up that crappy 91 octane. I also for got one thing...or atleast worded it incorrectly...

also your injectors will need to be changed due to crapy 91 octane heres an injector link>>>http://www.roadraceengineering.com/eclfuel.htm, just scroll down a little bit.

You will only need to up your injectors if you just use 91 octane, the higher the octane count the smaller injectors you can get away with using at higher boost levels. Also when I stated CRs(compression ratio's) of your pistons had a lot to do with boost levels as well, I ment this is terms of lower CRs allow you to run higher boost levels on pump gas, I.E: you can run higher boost levels or 8.5:1 pistons as compared to 9:1, its not a heck of a lot more but its more.

Dustin

 

[fourreGsixty3]

Also if you would like to learn a little bit more about meth. myself and Don have some posts discussing it through out the site, I think mostly in the bolt-on section, and maybe 1 in the cyl/short block section.

Dustin

 

[Kevin Jewer]

I'll also say that you should go ahead and do the external now, just becuase it will still be needed with the 30R. If you go with a bolt on 30R, like SBR's GT12 or similar, it will still work with your investment. SBR also sells cast manifolds with the Tial 38mm flange cast right into it. This seems to me the easiest way to go. A 1bar spring should do well for both turbos. Any larger than a 30R though and I would go stiffer. For the stock flapper, you can wire it shut if you don't want to go permanent yet, but anyone (even me, and I'm not a good welder) should be able to tack it shut. I like to tack it on the outside at the lever, so I can cut it off later. I seem to have a problem with making things permanent.