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Discussion Starter #1
Long story .... short version :
car engine: D15 Mini
cam : st7 RM
valve springs: RM crap
After 100 miles with new cam and valve spring, the car stop make power after 7600 RPM . Engine start to vibrates and make strange noise. After We change ton of parts and spend ton of money in the end to find the problem is Valve Springs . And this is not on one set , noooo this happen on one more car whit the same setup.
After We contact with RM , Hi do nothing !!!! Yep ... just nothing ....
If U think to use RM products - I do not recommend you ! Zero quality and zero support!

Thank you RM!
 

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Prelude, Integra DB9
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I don't really know how to read the dyno graph, but could the double-dip at the end be valve bounce?

Also, I'm surprised that 55 bhp is lost between the bhp and whp. I guess this depends on how the dyno is set up.
 

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Discussion Starter #6
Is the spring image you have showing that the valve springs have sagged? I see that they're different heights.
One man to know what to watch .

This is one EX and one IN sping . If compare with not used it will be worse.
Springs is not ONLY sagged . Spring rate is so different on IN springs , u don't need to measured . I can catch the difference only with hand push.... so obvious !

Now put BC spring and everything is OK. After few days I will post dyno with new springs .
 

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Discussion Starter #8
Yep, didn't do anything ! Hе said " Springs can sag a little " phahaha And if this is a men who have technical knowledge , I am a quantum physicist ...

When we exclude the different spring rate ( wtf different spring rate ... no need to comment) 1mm sag on spring leads to 60NM (if spring rate is 6kg/mm2) LESS preload in static position. And u have less this force number in the entire stroke of the valve.
 

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So you contact the company, and they didn't respond?
After all the hoopla on the Facebook group, I doubt Rocket will respond to much. He seems to be catching some flack as of late.

Sorry that I don't have much to contribute to the thread but Bone made a good point. I'm sorry you had such a bad experience with RM. I've heard nothing but good things about him in the past. I wonder what happened.
 

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Brokedick Millionaire
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Revving it to 9000 rpm might be the problem with a .500" lift cam.

ZXi 4.437 FD, ZC 1-4, .702 5th, OBX LSD....

I just wonder what he did to the D15B2 pistons for valve clearance, or were different pistons used?

Google is a funny thing...
 

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Discussion Starter #11
transzex , I do not know why you think the car is this one ... you described my everyday car . But FD is 4.9 .
The car with the shity springs ( to be accurate 2 cars) is a race car. And 10x to RM half a year we didn't race . We just spent tone of money to find what is the problem....
 

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your first post says you threw a ton of parts/money to find the problem. Seems like it would be obvious to start with the recently replaced parts before getting your wallet out.

Valvesprings do sag a bit, and they certainly have a certain rev range they are designed for based on teh cam profile.


Can you provide more information on parts used and how you put things together?

rocket motorsports has pretty large customer base, and its not just for the parts alone.
 

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Discussion Starter #13
Because the springs was the last thing we expected. Everything was brand new!!! RM guarantees that the springs are high quality, well-processed and will not have problems for the purpose..... yep .... no problem ....
We paid for 3sets of quality springs , and received 3 plastic bags with dog shits inside.
 

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That dyno graph doesnt indicate anything that I can find. Looks like a single dyno run with 2 extra power curves drawn on.

I could pull two plug wires off my accord and run the bottom curve lol


What are these curves showing us?

Looks like all show healthy 8k rpm stability
 

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89 EF 4wd sedan
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That dyno graph doesnt indicate anything that I can find. Looks like a single dyno run with 2 extra power curves drawn on.

I could pull two plug wires off my accord and run the bottom curve lol


What are these curves showing us?

Looks like all show healthy 8k rpm stability
I think that graph is what the initial dyno run was like before the springs sagged and now there's a power problem at the top end. If you compare it to the dyno graph in the first post you can see theres now a problem at the top end.
 

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in the first post, I see 7k rpms, dipps down, then climbs back to 8k rpm

this second graph shows a steady climb to 8k, then trails off.

Maybe spring shims are in order.

Be sure to measure the spring compressed to prevent coil bind, as that is a great way to make a valve turn into a pretzel or wipe a cam lobe
 

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in the first post, I see 7k rpms, dipps down, then climbs back to 8k rpm

this second graph shows a steady climb to 8k, then trails off.

Maybe spring shims are in order.

Be sure to measure the spring compressed to prevent coil bind, as that is a great way to make a valve turn into a pretzel or wipe a cam lobe
Would you waste your time shimming a spring that has visibly sagged over only 100miles? What would it look like after 1000 miles? :wacko:
 

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Discussion Starter #19
EFB055, springs is not only sagged . Yesterday I talked with the other person with 2nd RM set. They measured the spring rate of some springs. There was a differences of 3 kg/mm2 ...... His car is not more than a 20-30 miles.
You are a technical person, and probably You know even if spring is sagged , the rate must be the same. The different rate can only be due to poor quality material.
 

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poor material, bad batch, overheated treatment.

Either way, 3 sets not meeting a standard needxs attention from rocket.
 
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