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Ok, I know this is a long shot, but..... does anyone know of an ITB set up for the V6s that we run? I'm hell bent on having one and I was hoping I wouldn't have to have it custom machined(i.e. LOTS of money that i don't have).
 

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Teqnyck said:
Ok, I know this is a long shot, but..... does anyone know of an ITB set up for the V6s that we run? I'm hell bent on having one and I was hoping I wouldn't have to have it custom machined(i.e. LOTS of money that i don't have).
Doesn't exist.
 

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yup go the custom route.... Bartley was going to have one made by paeco engines, but that apparently fell short.
 

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when I was a kid I saw a thing on tv where they super glued a elephant to the cealing I wonder if it was real did anyone else see that?
 

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Yeah, I believe they had a commercial where they superglued a midget (sorry: vertically challenged person) to an I-beam once too...

As for the ITB... other than for looks, why do it? You realize you will lose the benefit of the VRIS system, too... I would hate to see that go on this wonderful motor.
 

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Alright. Two things wrong in this thread. There is an ITB setup for our cars. Now, whether it's available for people like us to purchase, I'm still finding that out right now, as I am trying to purchase them.

Second, as far as Schwinn's comment goes, ITB's are never for looks. If you buy them for looks, you'd have to be the biggest moron in the world, and I'd have to kill you. If you're at the point that you need ITB's, then VRIS is doing jack squat for your car. Probably hindering its performance. That's why in race motors, there's no such thing as things like VVT or VTEC. ITB's are the only modification available that will increase power across the ENTIRE powerband. Each individual throttle body has a smaller plenum than the stock intake manifold. This means the air has a higher velocity at low RPM's. This in turn means more low end power. But the overall volume of air being brought in by an ITB setup is much higher than stock.

ITB's are a great modification for those of us who've done enough to our engines to warrant it. That said, most people won't see any benefits from ITB's, as the most that most people do to their MX-6/Probes is get a ZE, if that. I'll list some of my big mods to give you an idea of where you should be before you consider going with ITB's.

High lift/duration camshafts.
11:1 forged pistons.
Titanium wrist pins.
Interprep valve springs.
Titanium retainers.
Long primary headers.

I'm running a ported manifold right now, among other things not listed, and yes, it's acting as a restriction. If you've gone this far, ITB's might be just what you need. But never, EVER buy them for aesthetics. You need a standalone fuel management system to run these, and it's not a lot of fun. Only purchase these if you're wanting to spend SERIOUS cash and time.
 

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I am building a KL-powered Miata that will have ITBs. Mine is using a stand-alone engine management system (Autronic), but the complete intake manifold/ITBs/fuel rail/injectors/throttle hardware, etc., will be designed by the end of the year.

The first iteration of the system is nearly complete. If you like, keep in touch with me and I'll give you updates as the system is developed.
 

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I am sure we would all be curious to know how it goes. Any improvement to the KL motor will be well received by this group. However, do note that you are fighting the odds - everyone has alrady considered and tried performance adders on the KL motor, and have not met with tons of success. I don't believe that you will find much either, but I am willing to eat crow if you prove us wrong.
 

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As was stated here, ITBs may make very little improvement in power and not worth the expense -- on the other hand, throttle response should be markedly better, and the sound itself might be worth the expense.

MX6/Probe owners have done a lot of experimenting with the KL, and I think it's pretty clear that within the limitations of good daily driveability and cost, 170-180 whp is about the limit. But that's pretty good, and comparable to the 240, or so, a 350Z gets, w/3.5 liters. The most advanced engine I've seen is one on Probetalk that's putting down 217, and that's with stock ignition, fuel, lifters, and modest cam timing and compression. 217 is impressive in it's own right, but he's also producing that at 7100 rpm -- far below what the engine is capable of; and where the real horsepower is. I think his dyno plot underscores the fact that the engine is induction-limited.

As far as I know, no-one has built a really serious KL. That's what we are going to do. Because the Miata is very light, has a generous range of final drive gears available, and will be strictly trailered (autocross) we can try things that aren't feasible for street MX6s.

BTW, my sponsor and I have been talking about this project for years and are now taking on the boosted Miatas and MR2s -- boy, are they going to be surprised!
 

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Lateapex said:
As far as I know, no-one has built a really serious KL. That's what we are going to do.
Guess the handful of 400+whp ones aren't serious enough for you?
 

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Well, there was the BTCC Ford Mondeo in the mid-late 90s with a 2 liter KL (de-stroked from 2.5L). Apparently, it was making about 315hp from 2 liters. It had an ITB setup with individual trumpets. Of course it also had custom heads (modified by hand) that supposedly cost more than F1 heads of the day. It was prepared by Cosworth.

See also this Sport Compact Car article.
 

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Lateapex said:
As was stated here, ITBs may make very little improvement in power and not worth the expense -- on the other hand, throttle response should be markedly better, and the sound itself might be worth the expense.

MX6/Probe owners have done a lot of experimenting with the KL, and I think it's pretty clear that within the limitations of good daily driveability and cost, 170-180 whp is about the limit. But that's pretty good, and comparable to the 240, or so, a 350Z gets, w/3.5 liters. The most advanced engine I've seen is one on Probetalk that's putting down 217, and that's with stock ignition, fuel, lifters, and modest cam timing and compression. 217 is impressive in it's own right, but he's also producing that at 7100 rpm -- far below what the engine is capable of; and where the real horsepower is. I think his dyno plot underscores the fact that the engine is induction-limited.

As far as I know, no-one has built a really serious KL. That's what we are going to do. Because the Miata is very light, has a generous range of final drive gears available, and will be strictly trailered (autocross) we can try things that aren't feasible for street MX6s.

BTW, my sponsor and I have been talking about this project for years and are now taking on the boosted Miatas and MR2s -- boy, are they going to be surprised!
chris(streetthismx6) put down a little over 200whp in his daily driven mx6. Ty has had a KL bored and built to a displacement of 2.8, but hes never had his car tuned or dyno'd :shrug: and thats just in Cincy. both of them are stepping away from these cars for now though.

anyway, good luck with your car. sounds like you'll actually be putting some good thought into your setup, it'll be nice to see someone that actually takes this engine to its limits. I thought Ty would, but he stopped on his car when he was so close to the finish. if Ty would have finished i would have expected around 600whp Turbocharged. Chris didn't even get his new motor started before he had to stop. I think the KL should be able to push 270+whp N/A if its built for it, that would most likely mean spinning 9000 or more RPM, but i think its possible.
 

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I can bet you that the BTCC Ford Mondeo engine made power not because of ITBs, but more because of high compression, agressive timing, the custom heads (with different valves), and a custom lower end. All this can be had to make POWER... but the question is, at what RPM?

As the Bradbury site stated, the KL engine was used in race applications where they could run at 10krpm... your stocker won't survive that.
The IMSA 2.5V6 engines produced 430-480bhp from the 2.5V6, the 2.0V6 was 380-420bhp, all in race only form."
The key words being "in race only form"...

At high rpm, though, you probably could push a decent amount of HP with the addition of better breathing (intake and exhaust - ie, HEADS)... but again, you are dealing with a whole custom engine, not just a stack of ITBs slapped on to the stock KL.
 

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Schwinn, noone puts ITB's on stock motors. ITB's do make power. But they only do that once the engine has been heavily modified. If you put it on a stock motor, yes, you are wasting your money. ITB's are not the most cost-effective modification in the world. In fact, they are one of the worst as far as cost-efficiency goes. Hence, it is only a modification for people who have already put in an extensive amount of money and time into their engine, but are still looking for that extra bit of power. While probably costing Cosworth around $15,000, the ITB's were probably only responsible for about a 40 hp increase. But that's still around 40 hp more than you would have without them. Should anyone on here get it? 95% of people here should not. Is it worth it for someone who's building an all out NA race car? Yes.
 

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Lateapex said:
Yes, that's the target range: 250-275 whp @ 8500-9000 rpm.

Thanks for the wishes.
Best wishes from me too.

I've been hoping someone would do this for years. Please let us know how the project is going. Personally, I have a very big interest in high-rpm KL use, and the idea of someone shoving one in a Miata is particularly attractive considering all the naysayers over the years on that application.

Let us know how its going. :)
-Garrett
 
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