i apologize if this topic is old......

but with all the talk about vortech vs. comptech vs. speedcraft......

i havent really found any posts on how reliable they are, how they are designed to overcome the situation with the high compression of 11.0:1 .

people with the speedcraft.....was it hard to tune?? is the FMU all the kit needs for standard psi??

what is each kit rated at for HP and at what psi??

i cant seem to grasp the idea how 6-8 psi of boost to a motor with such high compression be reliable. especially over a longer period of time (and daily driven).

thanks in advanced for any useful info.

i hope to gain some more knowledge that would ultimately help decide which system i will choose.

 

I've heard of a few people running the Speedcraft kit for up to 10k miles having no problem with the kit set at about 6psi. Some people have tried running it to 8psi and have run into problems while others haven't. I just bought a speedcraft kit, and I'll be using the FMU along with the AEM ems stand alone computer which enable me to run up to 12 psi since you can lower play with the timing. However I'll probably only run 8-9 psi to be on the safe side. Hope that helps.

 

[QUOTE]Originally posted by RevIllusions
[B]i apologize if this topic is old......

but with all the talk about vortech vs. comptech vs. speedcraft......

i havent really found any posts on how reliable they are, how they are designed to overcome the

 

If you do a search, I'm sure you'll find most of your questions answered. My sense is that provided that you don't run too much boost, the engine components won't implode, but you'll have to upgrade your clutch as the stock clutch can't handle the sort of power generated by any of these kits. Provided that you don't do any high rpm clutch drops, the drivetrain can probably handle the power but a lot depends upon how you drive the car. There's not a lot of data out there, so we're all charting new territory. The Speedcraft turbo kit doesn't seem to have suffered any catastrpphic failures (at least none that are attributble to the kit itself). I've heard some problems with the Comptech S/C kit relating to stressed on the crankshaft caused by the pulley, but I don't really know any details and haven't paid the issue any attention. Like I said, do a search and you'll learn most of what you need to know. This issue's been hashed out a lot on the boards. If you're really serious about laying down the bucks for any of these kits, then you should call the companies and talk directly to them, just as you would before you bought anything worth $5K-$9K.

 

Addendum: tuning is pretty easy for the Speedcraft kit, at least it was for me. V-AFC plus FPR and a few hours at a decent tuning shop. The kit comes with an upgraded fuel pump. But I agree with JerryPeterson -- reliability? Nobody really knows....

 

What about going N/A? with Toda cams and etc....... more reliable?

 

This is what I heard about N/A reliability vs. F/I:

With N/A, either your motor blows or it doesn't. You don't get any warning or things of that sort, it just goes.

With F/I you get some leaks here and there giving you some sort of warning that something else might be on it's way.

I don't know how much truth this holds, just what I've heard.

 

Nope VTEC Racer, in reality, failure modes of all sorts occur on both types of engines.

But, on NA engines you're not likely to have a failure due to detonation (except maybe on really high compression engines). These sorts of failures cause piston failure (holes in piston crown, broken rings, broken ring lands), bearing failure in the rods and cranks, and sometimes you can even bend a rod.

By comparison, NA failures usually occur in one of two areas. Either something fails in the valvetrain, or you lose a rod bolt. Both are due to high rpms, and in the case of the valvetrain, high rpms with big cams.

Both sorts of failures can occur on both types of engines, especially if you're revving the turbo motor to high rpms, but you just don't see many FI type failures on your typical NA engine. And you don't often get much warning of failure on either motor. On FI engines you can wear out the engine (bad ring seal for example) and you'll see warning signs, but that's not really failure, just wear.

UL

 

Thanks UL, thats more undestandable.

With F/I, what are the most common things that go wrong with the car and what can you do to prevent each thing from happening? What are the symptoms of these problems?

 

[QUOTE]Originally posted by ultimate lurker
[B]Nope VTEC Racer, in reality, failure modes of all sorts occur on both types of engines.

But, on NA engines you're not likely to have a failure due to detonation (except maybe on really high compression engines).