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-   -   Microtech Is LT8 better than LT4? (https://www.rx7club.com/microtech-111/lt8-better-than-lt4-231263/)

luiml73 10-09-03 10:47 PM

Is LT8 better than LT4?
 
A friend of mine found a brand new LT4 for $650. He want's to know the difference between the two. All I could answer him was that the LT4 only controls fuel, and that he'll have to switch to a distributer on his T2.

For a Daily driven T2

1. Can the car be tuned just as good for street driving?

2. Can the car be set for great Gas milege as with a LT8 or LT12.

3. Is it easier to tune the car, because you don't have to deal with timming.

Thank's

Luis

GTRay 10-12-03 07:25 PM

The problem he will have with running a distributer is that unless it's a 12AT dizzy he won't have any way to retard timing for boost which isn't good for power or reliability.

The LT8 is the much better solution for his application!

tuning for fuel will be the same with the 4 as it will be with the 8.

when it comes to tuning the ignition curve tell him to PM me and i can help walk him through it.

Ray
BR7 Racing

luiml73 10-12-03 11:43 PM

Well we installed it on Sat. with a regular 12A dist. And the car started up. I switched it to Tps mode cause he has a bridgeport. A fellow Puertorican Mechanic welded the distributer 10% and 14%. I'm not to sure exactly what they did, cuase I was busy messing with my LT8. But the PR Mech. has been working on rotaries for 20years and has a PP nitrous starlet. I tried to tell them about the 12A-T dizzy but they would'nt listen.

I don't plan on pluging my laptop to his car anymore. I don't want to be blamed for anything that happens to his car. I told him to take it to Rolo or someone who's been dealing with MT's for a while.

He's new to the forum so I'll tell him to PM you.

One more thing......The LT4 only has 2 bulbs on it, and the red one comes on and stays on all the time. I ran it on test mode, but error's are OK.......Any suggestions?

Thank's

Luis

10sec rx7 10-13-03 02:18 AM

on a LT4 the red is power and the other is ignition pluses from memory!

Dale

GTRay 10-14-03 11:53 AM


Originally posted by luiml73
Well we installed it on Sat. with a regular 12A dist. And the car started up. I switched it to Tps mode cause he has a bridgeport. A fellow Puertorican Mechanic welded the distributer 10% and 14%. I'm not to sure exactly what they did, cuase I was busy messing with my LT8. But the PR Mech. has been working on rotaries for 20years and has a PP nitrous starlet. I tried to tell them about the 12A-T dizzy but they would'nt listen.



Luis

The only problem i see happening with the dizzy welded like that is that he won't have any vacuum advance so his cruising mileage is going to suck balls and he won't have any low end power - it's going to rev slower and that's going to effect turbo spool up time.

they need to make sure they know what they have - the LT4 has 4 injector drivers and has all the same fueling features as the LT8 - they shouldn't have trouble getting it to work in staged injection mode for a 13B - it seems to me that the problems they are having is figuring out just how many injector drivers they have.

NanaimoRx-7 10-14-03 05:16 PM

Since we're already discussing the model differences, I'm going to try and toss a quick question in here.

I was thinking about using a Microtech to run EFI; 50mm IDA style throttle bodies on Weber manifods for a large extend port 12A. Would the LT4 be sufficient and leave the stock dist. for timing. Or will there be a signifigant improvement moving to the LTX-8?

Thanks, George.

10sec rx7 10-14-03 05:39 PM

Ray,

some LT4's only have 2 injector drivers, he may have one of these,

NanaimoRx-7

you will always gain more from a fuel and ignition ecu, but if on a budget the LT4 will work a treat, but the tuning on the LT8 is always going to be one up due to the ignition control.

Dale

GTRay 10-14-03 09:08 PM


Originally posted by 10sec rx7
Ray,

some LT4's only have 2 injector drivers, he may have one of these,

NanaimoRx-7

you will always gain more from a fuel and ignition ecu, but if on a budget the LT4 will work a treat, but the tuning on the LT8 is always going to be one up due to the ignition control.

Dale

thanks dale, i wasn't aware of a 2 driver LT4 - learn something new everyday! i thought the only ecu MT offered with only 2 drivers was the MT2

oh well... looks like you have a rare LT4!

10sec rx7 10-15-03 05:27 PM

Most of the ones sold here in AUS are 2 driver, same as a digi 1,

Dale


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