no boost at 6000 rpm in 3rd gear ¡¡¡

niss506 · Feb 25th, 2003, 01:54 AM

Hi, I'm new to this forum, but I have read it for a some time now.
I just finished my turbo instalation (mitsubishi td05h turbo, custom manifold, external wastegate, rx7 intercooler), and i'm getting familiar to the transformation. Among the few things that I have notice is that: 1st gear everything perfect, boost all the way from 3000 rpms, at 10 psi, 2nd gear perfect as well, but: 3rd gear at 5600 rpms no turbo responce and seems that the engine its not responding, same in 4th, and 5th.
I hope I would be fixing the problem with the adition of apexi's S-AFC, boost controler, an BOV.
Any sugestion on what could be happening so far ?
Thanks in advance for you help.

javierb14 · Feb 25th, 2003, 02:32 AM

what are u running for engine management?

**chimmike** · Feb 25th, 2003, 09:15 AM

that's a big turbo.....I also ask Javier's question.

also, Javier, did you get my PM?????

niss506 · Feb 25th, 2003, 09:33 AM

No Engine management so far, (stock computer) wednesday I'm getting the a'pexi, s-afc.

**chimmike** · Feb 25th, 2003, 01:04 PM

for one thing, you shouldn't be running a turbo without a wastegate............for another, what fuel system upgrades have you done? injectors? pump? FMU?

niss506 · Feb 25th, 2003, 02:28 PM

Stock injectors, pump and MAF.
I'm running a wastegate. It's set at 10 psi.

James · Feb 25th, 2003, 02:35 PM

is your wastegate malfunctioning?

niss506 · Feb 25th, 2003, 02:38 PM

I don't know for sure, how could I tested ?

**chimmike** · Feb 25th, 2003, 02:42 PM

I think your problem is you're probably running lean, with stock injectors, MAF, AND pump...................but that may not be the whole issue.

niss506 · Feb 25th, 2003, 02:45 PM

Thanks for your replies, I'm thinking in not using the car until I have control over the air/fuel mixture. (via the s-afc). In that way I can discard the running lean condition.

James · Feb 25th, 2003, 02:48 PM

well, I don't really know except by watching your boost gauge to know when the wastegate opens. I mean you can hit redline in 1st with full boost right?

hazar_ser · Feb 25th, 2003, 06:05 PM

Dude b4 you get the safc, I think you should get some bigger injectors(370,550) and an upgraded fuel pump(walboro) and upgraded MAF(Cobra, Bored stock). The money will be well worth it. My friend has a tiny t25 and hes hitting 85% duty cycle on 370's, and 4.9v on his stock MAF. So you are probably maxing both.

Just my $0.02

javierb14 · Feb 26th, 2003, 01:31 AM

without an EMS, i wouldnt boost the car at all! even with the AFC, how will u fine tune the A/F and timing? IMO if u do buy the AFC, at least rent some dyno time.

chimmike im im'd u back

**chimmike** · Feb 26th, 2003, 10:22 AM

gotcha Javier, thanks

Feb 26th, 2003, 02:43 PM

I bet you're running way lean, and probably detonating. Stock injectors are only good for what, 180 wheel HP at the most? Out of curiosity, do you know what detonation sounds like? It's sort of a high pitched metallic ringing sound, and it'll be somewhat quiet unless you're detonating really badly.

If you ever hear that, immediately get off the gas and don't get into the boost any more. Detonation is extremely destructive to your internal components, specifically your pistons, rings and head, not to mention your cylinder walls.

And you shouldn't be driving it with no engine management, that's what causes motors to go boom.