how far is too far with the WG adjustment?
 

Hey there all,

I've got a 99 automatic miata with the BEGi-S turbo kit (2554) and their FMU setup on the car but do get some knock at higher RPMs.

So far my boost gauge will show that I'm hitting 6-8 PSI when the auto kicks down and of course along with that comes the knock. I've unscrewed the wastegate adjustment lever as far as I can go before it forces my WG open without any movement of the actuator rod. (looks like 1/2 turn more will crack open the WG.)

What would you all suggest I do to keep my boost down @ 5PSI or so until I get some engine management taken care of?

Honestly since driving 1000 miles on this setup...I've yet to be able to go WOT and it's bothering me something fierce... :crx:

Future plans call for 315cc Volvo injectors this weekend and some sorta engine management by April.

Thanks all and cheers!
Prospero

Attachment 5867

What gas are you running? What did you set your timing to?

93oct and timing set correctly, you should not be knocking.

I also don't recall any Volvo injectors being compatible. All fuel injectors are not the same... did somebody tell you they'll fit?

You can crack the WG rod just a little more. That turbo will actually make 2-3psi at WOT with the actuator rod completely disconnected. Back it out a little more until you get the boost you want.

I'm using Chevron 93 for fuel and the timing is stock... being a 99 I don't think that I can adjust it unless I have some engine management.

The volvo injectors should be compatible since they are high imp and I've got the wiring adapters in-hand. They are the same things as the RC550 injectors in terms of size and shape. (just not flow) But please correct me if I'm wrong here... it would be a waste of time if I just dig in. :noob:

Here are the injectors that I've got from an old project.... http://cgi.ebay.com/ebaymotors/VOLVO...QQcmdZViewItem

As for the WG rod, then I'll give it another 1/2 turn and see what happens since I'm itching to get her WOT and fully tested.

Thanks for the advice and I'm open to suggestions!

On occasion, if the pushrod does not have some preload the gate will overboost.

Im sorry to hijack, but what model K&N is that air filter begi uses?

I believe it is the RU-1500 model.

edit: Nevermind. The RU-1500 is oval and that one is round. Sorry

I believe the one that came with my begi kit is the ru-1500(oval shaped)

It is an RC-4340.
Stephanie

prospero, you are right, i dont think you can reduce your timing on the 99

just try and stay out of boost until you get some management in there, or get some WI

Seems to be a common occurrence with the pre-ported wastegate kits.

Yep, that's the one! Thanks Stephanie. :)

Well I'm still tryin to figure this out... if anyone comes up with some ideas, please share since I'm going to get drastic on this setup soon! I wanna go WOT and have some fun! ;)

Cheers all!
Prospero

Let's turn the boost down. That should help with the knock.
Stephanie

Yep, that's what's going to happen tonight when I get home. I'll extend the WG actuator and see what happens. I'm feeling great about this kit and just need to spend more time under the hood tuning it in a little.

Stephanie, you all are great and with the help of this board, yourself and Corky... I went from a new miata owner to a somewhat educated consumer in a matter of weeks. Thanks all for the support and have a great weekend!

Cheers,
M@ (Prospero)

Though I dare say the fix is a real EMU, even a piggyback, you could dump octane booster in.

You can retard timing overall, which will hurt off-boost performance. I did it once like this:
http://abefm.smugmug.com/photos/240508914_zqjbc-XL.jpg

But I wouldn't recommend it. :-)

I think the volvo injectors I had didn't fit in, they worked great in the FM piggyback manifold I had, but they were also low-ohm injectors. Having the rod adjusted very far out (out at all) really hurts spool, but I guess at this point maybe it's good. Certainly any intake or exhaust restriction would help (you still have all your cats?) or pulling the turbo and porting it.

Lastly, you can make something like this:
http://abefm.smugmug.com/photos/252576736_oYZc8-L.jpg

See more here:
http://abefm.smugmug.com/gallery/430...Nw6S#252576736

The idea is to open the wastegate further when it's open. I have more pics showing how much the wastegate opens.... You can really help it a lot.

AbeFM,

So looking at the image, you relocated the sensor to retard timing? I think that is what I'm seeing, right?

Anyhow, you're right about the ECU issue. I've decided to peace meal a MS system together since in parallel it looks like I'll be able to get it all to work afterall. (At least this is what I am being told by reputable sources.) ;)

I've ended up adjusting the WG to allow it to stay open all the time and it sucks at low speed while building boost; but once there...it will peak at 7PSI. It's drivable for now but all told, the turbo is going to Bell for porting and I'm just going to squirt / intercool the car in the end. It's just too hard to keep low boost... oddly. (Never thought I'd be saying low boost on purpose.)

Anyhow, thanks all for the suggestions! I'm going to drive the car for a while and save $$$ for an ECU and IC.

Cheers,
Prospero

Prospero, why don't you contact Chad (cjernigan) about an MS in parallel. He built one for my 96 and I know he runs one in his car.

You'll be really glad you have an ECU. I liked my piggy for all it's troubles, and I like my MS. At least on a pre-99 they are well worked out. You shouldn't have all the troubles I've had. :-)
-Abe.