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Discussion Starter #1
It is all a time someone having trouble, it is me... but now it is OK... cool.

Long story short:

On the Katana kit, the throttle body (drive by wire) is bolted directly to the blower inlet tube. The original way is to bolt the throttle body to a rubber flange.

This arrangement created in my case enought vibration to loosening small screw inside the throttle body, and created the code P0638 and P2104. Since you are not supposed to dismount the throttle body, I did not... but the screw was free inside.

When the trouble occured the first time, I just blocked the exhaust catalyser. I have now a de-cat pipe, not green, sorry.

Now, I did an adaptater plate to be able to install the rubber flange to the blower pipe. I also put Urethane glue on the screw inside the spare throttle body (without dismounting the cover, of course...). For your information, a throttle body is more than 2 000 US.

And now it works. An expert told me that the ECU was broken, for your info. I agree to say that it was not that easy to be certain of the real problem.

The car is back on track. Also, mine have also a very rought cold off-idle.
 

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Aren't you using different rods and pistons? This sure will affect the tune somehow. You could probably use a custom tune from Charlie.

Did you drive it hard yet?
 

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Discussion Starter #3
Darth,

My post was not regarding setting, which is very good when the engine is warm. The post was regarding potential trouble of the direct mount throttle body on the intake, like you did, or I did before to put back the rubber. I want to go in detail here, but the question is, are you willing to pay 3000 $ CAN for a defective throttle body?

Yes I drived the car hard on few occasion on street only yet, the first track session with the Elise will be at i-Car on may 30.

Yes the car have modified piston, and Crower conrod, and ceramic clutch (my pusher plate was broken), and modified transmission (my synchro was broken on second gear), as well as new rotor (since my rotor was crack), as well as ABS removed (since the ABS was leaking on valving inside). The car is ready to receive water injection too, but one step at the time, it will be installed when I will be certain that the everything is going well. Everything not under warranty... yes it was my fault, my responsability. The throttle body is something else.

You know me, and how hard I am on the track. But my Katana trouble occurs on street... yes, at probably 8500 rpm, right on the cutout because I like the cutoff...

By the way, are going on 23 at Shannon? I will be there with my 1969 Europa, 194 wheel HP, 1550 pounds.
 

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Sorry for your troubles. For sure your car is used the way it was meant to be.

I was supposed to be there but I decided to give my gf a racing course in a Formula 2000 car and this is on the same week end. But all my other friends are gonna be there (2 blue turbo Miata, red spec Miata, black WRX STi japan, black civic). It should be a fun day.

Good luck with the car.
 

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Discussion Starter #5 (Edited)
Up to date information. I know that I am moving slow, work, track, wife...

My de-Cat pipe was a Larini, and of course, it broke after 2 weeks of operation... cool (but received credit, thank, look like Larini have trouble with their weldment joint), and at the same time, it broke my Borla muffler. All the insulation material from the resonator of the Larini went to the muffler. But the muffler was too loud anyway.

I put back the original pipe, with the cataliser stuff removed. I put back also the original muffler, in fact, a new one (warranty) because it was cracked at the outlet pipe.

The car was running quite well, but something strange on the power band, peak torque at 6500, and decreasing, and increasing at 8000. I out the car on Dyno, and it was clear that it was a torque drop of 10%. The fuel air ratio was constant and perfect all around. The power peak at 8400 at 205 whp, and only 200 at 8000. Not bad, power is one thing, but the torque curve is lot logical. I was not feeling that with the Larini pipe.

Maybe the reason was the engine, or the exhaust. I decided to work on the exhaust.

Like I said, the exhaust pipe was the original one, with the catalyser stuff removed. Of course, the result was not ideal at all. The pipe is a one pipe divided in two, going to a 2 3/4 pipe of 3 inchs long, increasing to around 6 inches, and reducing with a big ball shape to the 2 1/2 bended pipe going to the muffler. I just buy a J pipe of 2 1/2, cut the original pipe to remove all the crappy catalyser canister, and weld that together with e weldment joint better than larini, I wish...). Of course, I welded the sensor plug.

I will try the car on Dyno on between 7 to 11 of August, and I will see the result. But as per now, the power delivery is looking nice, with a flat torque curve.

I did also another change, cheap one. My new muffler was already broken, with metal moving around itself. It was time to open it. The muffler is build with 3 sections. The inlet pipe coming from the left is going straight to the end right section (section 3) of the muffler, and the exhaust to going close to the insulated wall (the only place with insulation material inside the muffler). Another pipe is starting for section 3 going to section 1. It is no pipe between section 1 and 2. The separation wall is a perforated sheet with hole of around 3/16 diameter. I cutted a hole of around 1 1/4 in this sheet. The section 2 is the outlet section. The 2 pipes going out of the muffler have a section of around 6 inches inside the muffler. I cutted that and leave only 1/2 inch. Evryone will said that the changes I made are very small. Yes. But the sound is perfect, I think at I will be at the limit of the sound level (92 dBa) for race track around here, I will measure it on August 13. The sound is not too loud, very mature and full sound. Interesting, and cheap. But still an heavy muffler, I know.

Last thing, few poeple who have seen my car was asking where I found the added gage board, see the picture. I buy it from summitracing, but need to be flattened to fit the Elise dash.

Brand: Auto Meter
Product Line: Auto Meter Dash Pods
Part Type: Gauge Mounting Pods, Dash
Part Number: ATM-10001
Pod Style: Dual
Gauge Diameter (in): 2 1/16 in.
Pod Color: Black
Quantity: Sold individually.

I will let you know about the Dyno result.
 

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so you had to buy a new throttle body? Sounds like there is no way to check for this until failure. Was the whole purpose of the factory rubber flange to proect against vibration?
 

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Could you post a picture of the screw you are referring to as well as your adapter plate? I just installed a Katana kit for a customer and he is experiencing similar problems. It would be nice to see the fix.

Cheers,

Brian
 

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Discussion Starter #8
I will try to take the picture today and send it tonight.

The plate was made quickly, and a little bit rought. It was build with 1/4 aluminum plate, and fixed with 4 modified flat head bolt M8, plus 4 threaded holes to receive the flange,

The plate is not anymore on the car, I just replace the throttle body for a drive by cable.

Regards
 

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Discussion Starter #9
Please find the picture of the rubber flange. Like I said, it is rought, I did it quick not spending time for doing a nice job.

Like previously said, I also put urethane glue on bolt holding the mechanisc inside the dismountable clamped cover on the throttle body.
 

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