7MGE ITBs

[AJ'S 88NA]

I argue as forum members we spend millions in the aftermarket but we don't benefit like we should because we buy what is offered, allowing others to design for our needs. We should lead in design.

I agree with this as the amount we spend to get a few HP is kind of discouraging. At least NA, but the Turbo guys lay a chunk down also.
I have held off going turbo or NOS to see just how much in gains I can achieve without. One step at a time.

 

[AJ'S 88NA]

ECU, ITBs and manifold. You'd have to get it back to me in three weeks so that I could continue testing. I'd want to see a dyno and some tuning. But maybe we could do it later in the year, too.

I just took a look at your build and I'll put up a couple of studies for your expected performance. What size valves do you run?

Supertech +.05 3 angle cut.

Getting it all back in 3 weeks and dyno and tuning, at this time would be hard.

 

[sarinas_dragons]

If we did it later I might be able to send out a new ECU I'm going to test. I was thinking I could do a stock baseline and you could back-up my stock pull with a modified pull. Then I wouldn't be doing all the N/A and turbo testing.

I am going to have to absorb the ritualized criticism but Shawn and I are going to offer standalones and harnesses for $800 as an introductory price for the MKIIs. I guess they would work for MKIIIs but Shawn would be better able to answer that.

With everyone wanting proof of benefit by testing I think it is appropriate to consider for what results are people looking? Once I post up a couple of cam charts it will be easier to compare what I'm talking about. A example is the five cam comparison in the ITBs thread on cs.com.

It shows the mach value of the intake charge and how to alter the rpms where this event occurs.

It also shows how Toyota achieved some its performance goals by reducing pumping losses getting everything to move at the right speeds. In one post I show that once the intake charge enters the cylinder the port and valve and cylinder sizes and piston, rod and crank geometries all create the environment where intake charge speed and piston speed are equal at peak torque.

If I stay N/A and build with cams then Shawn will test the turbo manifold on his MKII. He loves punishment for his misdeeds.

 

[Junkie]

With everyone wanting proof of benefit by testing I think it is appropriate to consider for what results are people looking?


If I stay N/A and build with cams then Shawn will test the turbo manifold on his MKII. He loves punishment for his misdeeds.

Those that criticise for lack of proof by testing, usually have little or nothing to offer, except criticism. They claim interest in purchasing end results, yet never --- show the money, or spend time/effort of there own ... nuff said.


Yeah, I love punishment :naughty: The ITB/Turbo setup will accent the XX clone tremendously.

 

[sarinas_dragons]

Blow it the hell up for good more like it. Then will you put the Pauters and new pistons in?

 

[AJ'S 88NA]

Those that criticise for lack of proof by testing, usually have little or nothing to offer, except criticism. They claim interest in purchasing end results, yet never --- show the money, or spend time/effort of there own ... nuff said.


Yeah, I love punishment :naughty: The ITB/Turbo setup will accent the XX clone tremendously.

I'd love to have that system to try out, but the time frame and everything else going on right now I just could not do it all in 3 weeks. I understand about the need to get this system tested and tuned on several applications as to appeal to broader customer base, and I understand about the way other owners feel about putting that kind of money into a untested system and they aren't going to buy into it until some comparisons are made. And then only if there are enough gains to balance the cost.



There are some that would for the simple fact that they are "sexy" for go any comparisons as long as they worked.

Me on the other hand, can see if the system can be tuned and properly setup should produce fairly decient gains and would probably be a great asset to my build. The time and effort I've spent on mine has been a 5 year ongoing project, and it has been costly. Maybe not as much as some turbo builds, maybe more than others.

Sounds like you guys have a few cars you can fool with, I don't.


I've grown a little cautious with age I guess, I don't need to be any "sexier" than I already am:sarcasm:, I'm not out to set any new records, and I'm not out to blow anybody I can off the road/track. Like I've said before, just want to see what this "6 banger" is capable of without the turbo, and be able to drive it the way I want to. Drive it being the key word. Always somebody out there quicker.

Just my $1.17, inflation you know.

 

[Junkie]

AJ, in no way was I implying you, or anyone here as criticising the work we are attempting. Kenny knows of whom I speak. Those comments were for him, and some that may be following this thread, from elsewhere :biglaugh:

There are those that have made comments, basically claiming that the math may not be telling the whole truth. Math does not lie, but, accomplishing what it tells us, can be difficult at times

Although we would be pleased, if others would/could contribute, it's not an absolute need. It would just help speed things up.

At the moment, I personally have more time than money. I have the cars, I have engines to sacrifice, and am willing to to just that.

I am a fan of both NA and boost, and have cars I want to build for each. The next 3-6 months, should be entertaining for all interested :evil2:

 

[AJ'S 88NA]

AJ, in no way was I implying you, or anyone here as criticising the work we are attempting. Kenny knows of whom I speak. Those comments were for him, and some that may be following this thread, from elsewhere :biglaugh:

There are those that have made comments, basically claiming that the math may not be telling the whole truth. Math does not lie, but, accomplishing what it tells us, can be difficult at times

Although we would be pleased, if others would/could contribute, it's not an absolute need. It would just help speed things up.

At the moment, I personally have more time than money. I have the cars, I have engines to sacrifice, and am willing to to just that.

I am a fan of both NA and boost, and have cars I want to build for each. The next 3-6 months, should be entertaining for all interested :evil2:

No offence taken Shawn. I think I know who you talk of, Aliens.:biglaugh: I've been watching the other site also.

Wish I was a little closer to be able to contribute and learn. You guys seem to have quite a bit of knowledge, and spare parts:biglaugh:

I guess I'll have to drool from afar.:cry:

 

[sarinas_dragons]

It was like there was nothing going on and no prospects here, too.

Boast-master Shawn jumps into a fracas with no regard. I'll be along to back him up. For the last four years it would be an impossible list to compile the amount of hotrodding we've done for others.

I challenged him to be satisfied by working harder for himself than he has for others. He told me he'd never be satisfied. That's his fault. I'm just really nerdy.

 

[Junkie]

Correct, never satisfied, there is always -- the next thing

Just make sure your around, and we have a vid cam running, when I twist up, and explode the sacrifical 5m

 

[sarinas_dragons]

Here's another ITB build thread

http://www.preludepower.com/forums/showthread.php?p=1518991#post1518991

Inspirational!

 

[7M-fanatic]

Blow it the hell up for good more like it. Then will you put the Pauters and new pistons in?

I have had my NA over 8000 RPM with stock rods....
But I did recently switch out to El-Cheapo Eagles.
(or is that 'El-Chinese Eagles' ?)
Glad I did, because I had a rod bearing welded it's self to the crank at about 8500.
The rod held, and did not punch a hole in the block.
I doubt if the stock rod would have held together.

Now the engine is about to go back in (with more oil flow).
And I can get back to picking on near stock Mk3 turbo cars )

Here are a few ITB pictures from an auction in Japan.
I have started collecting AE101 ITBs so I can make a set of 6.
Eventually, they will replace the 70mm single throttle I am using now.

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[sarinas_dragons]

There is a little known spec that is a combination of engine attributes tha limits the effectivenes of an engine design.

The 7Ms based on their geometries experience this limit around 8400. Do not exceed this, no matter what your upgrades. There are some factors to consider, though. If you'd like a more intensive explanation I would be happy to oblige.

 

[cuel]

Actually, yes, that would be beneficial knowledge to everyone. There's a write-up by Supracentral here: http://www.supramania.com/forums/showpost.php?p=180719&postcount=18 , which I think may contain some of the information you're hinting at, but would like to hear your input as well.

 

[IJ.]

My "development" hard limit was 8300

 

[MrWOT]

Actually, yes, that would be beneficial knowledge to everyone. There's a write-up by Supracentral here: http://www.supramania.com/forums/showpost.php?p=180719&postcount=18 , which I think may contain some of the information you're hinting at, but would like to hear your input as well.

That's part of it. The other part is that your pistons will outrun the flame front and bmep (brake mean effective pressure, this is torque) will suffer enormously.

If you're curious, the most traumatic moment for the rods is the exhaust stroke, because the exhaust gases are already vented before the piston reaches tdc, there is no "cushion" like there is on compression, and power. And your rods (and the BOLTS!) do not appreciate this kind of loading.

 

[AJ'S 88NA]

What if you have a lighter weight piston with a stroker? Mine are weisco's and they are 317.8 grams. I didn't see any compensation for comparison in the formula in Supercentral's post about stroker motors. What I'm saying is if you stroke a 7M and use stronger rods, bolts, and lighter pistons and rods, wouldn't taking extra steps to keep the rotating masses down help in having the motor stay around for a while?

 

[cuel]

Mr.WOT: That is said in the link(about the exhaust stroke being the hardest), and made a lot of sense once it was brought to my attention. As far as the bmep, that motor would need to run a lower rpm shift point? Would a higher compression ratio help with that? Would it be possible to tune the motor in such a fashion as to bring the peak torque point into a safer rpm range?

 

[AJ'S 88NA]

My torque has increased as much as the hp. I haven't noticed stroking my 7M has caused a decrease in torque. But if it is possible to extract a little more torque I'd like to know. What about timing the cams a little differently to help out with pulling out a little more torque?

ITB's maybe?

 

[7M-fanatic]

Actually, yes, that would be beneficial knowledge to everyone. There's a write-up by Supracentral here: http://www.supramania.com/forums/showpost.php?p=180719&postcount=18 , which I think may contain some of the information you're hinting at, but would like to hear your input as well.

That thread has incomplete data......
Says nothing about rod length, or rod length/stroke ratio.
All of which dictates maximum piston acceleration (MPA) when the piston passes by top dead center.
MPA sets the maximum RPM point for an engine, as long as things like:
Valve train, Lube system, and Fuel & ignition systems,
are up to the task.

An engine, with set bore/stroke ratio, with a short rod,
can not rev as high as another with the same bore/stroke ratio,
and a long rod,
just because the piston/rod shock is greater at the top of the stroke.

And yes, lighter weight pistons will increase the rev limit.

But I will work through the formulas again,
(should have before changing the rev limit by 2k)
and see what they say for the 7M.

I haven't dug out those books since '78 or so
when I was building flat track bike engines,
and turning them ungodly fast......