How much boost/PSI can I get from my BEGI-S?
 

I currently have 5 PSI, in my begi-s GT 2554 turbo, without an intercooler. I believe it will go up to 8 psi, so i want to match an intercooler to what i can get it to. Thanks.

While am at it, I am either going to use begi's intercooler upgrade, but am considering this one from ebay;
89-93 Mazda Miata MX5 T28 Intercooler kit bolt on + BOV:eBay Motors (item 160379221216 end time Nov-24-09 17:55:45 PST)

Good, bad, or ok choice?

Be gentle, i'm still learning. I do know i need a megasquirt, and 5 psi is not enough boost, i will settle for 8.

That's what I used. Check my signature for diy. Do you have a wideband? If not I. Reccomend picking up one worth every cent

Simple: ebay intercooler miata

site:forum.miata.net ebay intercooler miata - Google Search

:facepalm:

You should be able to run 25-30 psi no problem

no but seriosuly, you should be able to get away with 8 psi with an intercooler. just listen for knock and be prepared to retard the base timing a little bit of needed.

edit: just noticed you have a bipes unit. turn it to 10.
you have a wideband?

I was going to guess this much if you completely disconnect the wastegate signal line. I'd like the OP to find out and get back to us on an actual number, that would be fun to know.

"Recommend" as in "I recommend you use a condom when you have sex". Not using a wideband can result in catastrophic failure - not always, but enough of the time that you should be using one.

I figure the efficiency would get so low that the boost would stop rising somewhere around there :laugh:

will ad wideband to the list.
 

Thanks for the input. Glad i don't have to replace the current turbo to get a little more boost.
If you where going to by a wideband kit to install, leaning towards reasonble price, where would you go?

Depends on who you ask. What is your idea of a "reasonable price"? Most people seem to like the LC-1. I've got it, works great, but if you dont RTFM you will have issues. The AEM Uego is also a popular choice. It doesn't read as fast as the LC-1, but from what I hear its quite a bit easier to install. If you are feeling adventurous and aren't bad with a soldering iron, you could try the JAW ( google it ). I think it comes in at under 100 bucks.

uego for 200 was what I considered "reasonable". Easy to install, looks and works good. Great wideband for a good deal.

If you put a MS PNP on your car, the turbo can be run up to 12 psi on a motor with stock internals.
Stephanie

Hi Stephanie
 

This is Charlie up in Fort Worth. The miata i'm asking about here is the test one you guys did a couple of years ago (smurf blue). She is rstill running great.

When you say 12 psi, does that mean with this turbo, or would i need bigger one?

this one. ditch those crappy band aids and get a real engine management unit, like MS.

Im gonna say go with the LC-1

Ive used the AEM and the LC-1 and there is a noticeable lag in the AEM, which is fine if youre just using it for monitoring it, but it can be very annoying when trying to tune AFRs

I know,
 

i'm checking my credit card balances now.

You'll find yourself doing that very often once you start modding your car:D

Haha so true, I find my car fund stack of cash depleting rapidly lately, and I haven't even started my IM build yet!

;)

"A girl cant get pregnant if shes on top, its gravity" Knocked up

.

That means you can run around 12psi safely before the rods in your engine bend. That's with engine management. Skip this forum conversation and just call up BEGI and talk with them.

You can run an ebay intercooler no problem but you will have to get your own couplers, clamps, proper pipes etc. That might be intimidating if it's your "first time".

Call begi.

Hey there! How is the smurf doing? Guess the boost bug bit, huh. :) Glad to see the very first 1.6L BEGI-S is still going strong!

You can run 12 psi on this turbo if you add larger injectors and engine management. The best bang for the buck is the MS PNP. I would also add an intercooler at that boost level too. You can do things in stages, but I would probably do the MS first.
Hope that helps,
Stephanie

The first BEGI-S
 

I knew it was the 1st for the 1.6, was there a 1.8 Begi-S before the Smurf?

Thats what im thinking, I can do 14-15psi I dont because its a daily driver but the t2554 cant do much damage with a good tune and a great intercooler.

the 2560 on the other hand may be able to do a better job at shredding internals.

But then again Im the guy who is still using a stock clutch at 11psi so I dont seem to be the norm.

Just installed a wideband this past weekend.
 

Just now noticed your edit Fult Tilt Bogie, will put the Bipes to 10 in the morning.
My wide band (AEM) reads about 14 when I am on the throttle, so far so good i guess.

FYI-I just got 1.8 rotors and an 1,8 open diff for $250 for all of it, so i guess tha's what i am doing next.

BUT- given my current setup (stock exhaust,5 psi, no intercooler yet) would i have more fun getting 3 inch exhaust, or megasquirt pnp next? I am building slow, learning as i go. Eventually I will add intercooler and up the boost.

Thank for the input.

Is this WOT @ full boost? Ive never used an FPR but i would think 14/1 is way to lean. In boost im at 11.5/1





Get a Megasquirt

14/1, thats at full boost, buut i only ran it once,
 

I will run it tomorrow and get more accurate numbers to post.

I am ordering a mspnp right now.

But now for the dumb question, so if i'm lean with the current setup, to correct the situation, adjust the bipes for more timing retard, but what else could be done to get to 11/1 at full boost.

Thanks in advance.

20 g's.

Bipes is for timing and the FPR is for fuel/air ratio (AFR). The 14 indicates 14 units of air per unit of fuel so a reading of 11 on your gauge indicates less air per unit of fuel, or a richer condition than a 14.

Are you familiar with a device called an O2 clamp? I'm going to take a stab that you maybe haven't (but the MS will solve the problem, too).

Have you read the FAQ in the stickies about how these things work and how NOT to blow up your engine? The MSPNP is not a 'plug in and forget' arrangement and will require significant effort to understand and operate initially. The PNP designation really only alludes to the fact that you don't need to solder and assemble it yourself. You will need to understand both what your engine requires and how to achieve that requirement. I am concerned for you that you did not realize that 14 to 1 AFRs in boost were a significant danger and that you asked about the bipes as a means to correct the problem.

I do have an 02 clamp,
 

I bought it used, hope it is working correctly, the led light comes on, i just copied off the testing procedure to check it out.
And thanks for your concern, you are right, this all new to me, so I am taking it slow, and i am reading to try and get it tuned correct.
The MSPNP is on the way, but i am determined to get a safe tune with what i have, in hopes it helps understand a little more before working with the MSPNP.

GEt the MAf delete. And a 3" bang bang exhaust.

Wideband readings revised.
 

My new wide band show 14/1 at lower rpm's, but when i am on the throttle in boost, it read 12/1,

12 or under is good but if u can get about 11.5 you should be golden.

When you are cruising along and not stepping on it and you're running under that 0 on the vac/boost gauge, 14-15 a/f is normal, when you get closer to the 0 you want ur stuff to start going towards the 13-12, when you go over it into boost you want about 11.5a/f

12:1 is lean. 12.5:1 is very lean. 12.9:1 is EXTREMELY lean. Have you considered hiring a tuner to ensure you don't damage your engine?

actually 12:1 is perfect however due to the heat caused by the turbo thats why people go lower

12:1 is perfect for natural aspiration / under 0 psi numbers since they dont have the added heat from the turbo.

Spec Miatas make the most power in the high 12s, low 13s IIRC. I've found that turbo cars make the most power at ~11.5:1. I've also found that they are very, very prone to detonation when AFRs go any leaner than 12.0:1.

1. Install BEGi kit
2. Enjoy Boost
3. Want moar
4. Get tired of blind tuning
5. Get MEGASQUIRT
6. ?????
7. Profit

We have tuned plenty of cars at 12:1, that make great power, and have no detonation. For a street car, 12:1 is perfect, as long as there is no detonation. There are many other factors involved, but we usually make the most power at 12.5:1, here at (almost) sea level.
Stephanie

To each their own. I set a GT2554R up on a stock 1.8, tuned it at 12.0, and then richened it to 11.6 and saw another 4whp. I believe Ben saw the same thing on his old GReddy kit (max power in the mid 11s).