phinsn98

iTrader: (2)

I had my engine replaced with a reman motor from Mazda in October about two months later I was taken the car down to my mechanic for some minor adjustments and wouldn't you know it I got in a race. I was driving south on I75 and a guy in a red C5 convertable was driving in and out of traffic like a mad man and then ends up on my ***. He does a fly bye on me. I was talking with my girl and told her I had to go. Go and play that is ! I decided to pace him, he was slowly accelerating. I got up along side of him and it was on at about 100. I did not want to downshift into 4th, I didn't want to pop a belt. I did not have my dual alternator pulley and it was slipping. I left in 5th. He pulled me and passed me changing lanes in front of me. Once the boost was built up I stayed with him upto 145mph (1 car length) until I POPPED the motor. It just fell on its face. I pushed the clutch in and the shifter was rocking back in fourth. I was hoping it was a vacuum hose. NO SUCH LUCK . Mazda replaced it luckily, but it turned out that the stock turbo shredded on the intake side. I guess the motor had some impeller for lunch instead of a vette. Well it turns out that I got a motor with new housings. To replace the stock he had a 89-91 turbo with a polished housing that he would sell me for $300. I was like OK. Anyway it has a different boost curve then the 88 did. I could get 10-11 pounds all day with the stock turbo with this one I get 4-6 in 1st gear and second then it goes to 11-12 in 3,4,5. The car also seems to run flat in the upper rpms. Almost like it is not getting enough air or fuel. Can't tell. My mechnic states that it is a bigger turbo so it will react different but should generate similar numbers power wise. He wants me to get a boost controller to dial in more boost down low. Sorry for the long post but wanted to get your input.

88TII, K&N cone, RB full exhaust, FCD

Later,
Dave

phinsn98

iTrader: (2)

bump

RETed

You cannot swap turbos unless you use the proper turbo exhaust manifold.&nbsp The turbo turbine inlet flange has different bolt patterns between Zenki and Kouki turbos...



-Ted

phinsn98

iTrader: (2)

It came with the 89-91 exhaust manifold. I'm sorry I thought everyone already new you couldn't bolt the 89-91 turbo to an 87-88 manifold. So now that were passed that what do think Ted? I've heard that boost is load based and the higher the gear the more load you put on the car thus the more boost????

later,
dave

RETed

It'll work, but I'm a bit puzzled why you're running less power.&nbsp The Kouki turbo system is superior, and you would feel boost a tad quicker.&nbsp The power delivery is a LOT smoother with the Kouki turbo system, so that's probably why you're thinking you've got less power?&nbsp If it IS less power, something could be wrong with the turbo itself...



-Ted

phinsn98

iTrader: (2)

Well I am just basing my question on the fact that I generate less boost in 1st and 2nd gear then before. It does not feel less powerful...it gets up and goes no doubt but it seems to fall on its face in the upper rpms. It will go all the way up with no problem but seems to run out of air in the rpms maybe it is my imagination. I'm thinking about getting a boost controller do you think it will give me more boost down low or do I want to stay away from this right now?

Later,
Dave

What boost controllers do you recommend.

RETed

Boost controller would definitely "wake up" the turbo...
I'm partial to the A'PEXi AVC-R lines of boost controllers.&nbsp For a little cheaper alternative, I've heard good review on the GReddy PRofec-B unit.


-Ted

BLUE TII

iTrader: (9)

Since the 89+ turbo has dual passage wastegate you aren't able to "over run" the wastegate in lower gears like you could w/ 87-88 turbo, right. While the wastegate is regulating boost you only get 7 psi; all "natural" boost over that is from ineffective wastegate. I think the machanic is right; if you are OK w/ running 12 psi, set your a boost controller at that so you get more boost in the lower load ranges again. This holds for your feeling of less boost in high rpms as well, as the 89+ turbo isn't boost spiking like the 87-88 one was. That is my take on it anyways...
-edit- by the way, are you adding fuel in some way for above fuel cut boost levels?

IWNTA20B

Looking at your sig, I hope that's not all that you have.
With that set up, you're going to pop the motor again.
When I first got my car with 19,000miles , that's the set up I had and all it took was one nasty race with a VR6.
A Racing Beat full exhaust will give you 10-11 psi easily.
If that small GTR wastegate isn't ported , you 'll hit 14-15 psi in the higher gears. Before slapping on a GTX turbo, you better do something about fuel. You do have an aftermarket boost gauge and Air/fuel gauge don't you?

phinsn98

iTrader: (2)

Yeah I know about the fuel but I am trying to hold out for a Haltech instead of putting a bandaid on there. What would you suggest is the least expensive fuel additive that won't run me full rich that I can use along side a Haltech when I get it. By the way I have a boost guage and a rich-lean guage. The car runs pretty rich as it sits. No fuel pump added, no bigger injectors. I ran my car for 40,000 miles over the the 108,000 miles I bought it with. 20,000 miles of which I had that setup before the motor popped. I have never had a problem with boost spike. I have had the boost go as high as 15 on a very cold day but I expected it and I guess I'm lucky but the car was flying So instead of a boost controller...you guys think I should do the fuel thing next A???

Later,
dave

BLUE TII

iTrader: (9)

Fuel next? I think you should have done fuel FIRST. You know how FCD works right? You are running 15lbs of boost on 8lbs of boost's fuel when you let it creep to 15 lbs boost.

phinsn98

iTrader: (2)

The one thing that I am unsure of is how to rewire the fuel pump. I saw something that seemed like a fuel pump amplifier from MSD that I was looking at that seemed to do the same thing without having to rewire the pump. I guess I can add 720s and a Walbro or Supra pump to it with an Apexi SAFC. It just seems like a bandaid to me. I WANT MY HALTECH NOW Well I guess you gotta do what you gotta do.

Later,
Dave

BLUE TII

iTrader: (9)

For the fuel pump I just took a fused 12 gauge wire directly from the battery + to a normally open contact on an automotive relay. On the other side of the NO contact I placed the pump + (with 12 guage as well) and upgraded the - off the pump to chassis to 12 guage.. Next I took the old factory + wire to the fuel pump and ran it to the coil on the relay w/ the other - side of the relay coil grounded to chassis. This upgrades the stock wire and eliminates the resistor. I upgraded pump to Walbro 255 at same time.
If you get SAFC you can sell it when you get Haltech. Just make sure you have the fuel or stay out of boost as you save for Haltech because a new engine is alot more than a Haltech (as you already know.) I just recieved my Haltech and I was happy w/how comprehensive the booklet is. It looks like a fun project. I got mine w/ all sensors, a labeled harness (thanks Kris) and instructions for FCs ignition from Kris Kaminski revpower@newave.net.au for $1100 shipped. I have been very happy w/ his support. He has an FC that was running a similar set-up to what I will be so he was able to provide a base map that should be pretty close.