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Discussion Starter #82
Perhaps titanium pistons would help with the heat transfer issue ?
Or SS. I sent an email to AP racing if they can provide SS piston. BOE supply pistons for the front, but for the rear, I don't know where to find yet.
 

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Discussion Starter #83
For the moment, i will try with different brake pads, hawk DTC60, and changing my rear disc, they start to be thinner by 2mm. I am returning to long track on august 30, i will see. I am looking to change the caliper piston from alu to SS, I am not far, I need to improve the temperature rising into the caliper from 15 to 20 minutes on that specific track. I don't have trouble on other tracks down here. For my stock caliper in front, Wilwood are doing piston 1.75x1.03, and the stock one are 1.75x1.05, not far. For the rear AP 5317) with 1.62, I don't know the lenght, I suppose that it is also 1.05, but I will see, I ordered a stock piston. Wilwood are doing piston 1.62 and also Pegasus.

About the headers, PRL asked me to send my headers to them to maybe garanty it. I will know more next weeks, but to be honest, I am surprised about their service. I just sent a message saying that my new headers broke quick... without wishing any respond.

My car started to be louder, and my last track day at restrictive noise level track, I was touching the sound limit. I decided to give some steel bump on my muffler shell and the sound was like bumping on an empty can... look like the muffler is gone internally. Since I had one muffler in stock, I just cut my exhaust line to replace the muffler... and the muffler was destroyed inside. Not bad, the muffler keep up for 2.5 years... not bad, the muffler was in stock because it is not unusual to burn a muffler. Maintenance includes now replacing the muffler every 2 years...

After all, the car needs big care, the engine is rock solid, but big power is asking constant maintenance.

I did 2 track day last weeks, time to works on the car...
 

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Discussion Starter #84
Last track day done with a repaired headers, the stainless 304 is not clean with too much heat on the exhaust. Since my intercooler is small, the map retard the ignition to reduce the risk of knock. Last track done with only 11 psi boost and with water spray on intercooler. The intake temp rise at around 50 deg C, and the map is programmed to not give retard over 55 deg C, I removed the protection. The headers repair was rough caused by the contaminated 304, and the turbo flange not fully straight, filled by compound available to repair exhaust... I was pretty certain that it should break, it did not. I will nstall a new one this winter, already in stock.

Now my track season is gone. Plan for next years. I plan to run the car at 12 psi boost (instead than 14 psi), with a improved water spray system on intercooler, and no protection for air temp on intake. By calculation, my intercooler efficiency on track without water is as low as 55%. With water going to it, I expect an efficiency of more than 70% based on my few first trials. The set-up is not ideal at all, the air is coming from the bottom, and not enought flow to fill the water between the intercooler and the fan. I need to drop the water on the wrong way, from the top... It will take more water I guest. I tried with a 5 liters tank activated with a boost switch. 5L is quite small for 20 minutes run, I am trying to find a 8L tank. Another idea, looking stupid, is maybe try two fans in serie... I will probably try it during the winter on the working table, just to see. If the efficiency is going up to 70%, losing 2 psi of boost will not be that bad with the colder air, like an effect of 10 hp only compared with 14 psi and 55% efficiency. Not bad.

Brake wise, instead than carbone Lorraine pads, I tried Hawk DTC-60, and the result was great. The pads look like giving the same brake feel than CL-6, but look like create a better thermal barrier with the caliper pistons. The wear is a lot less, the CL-6 wears quite a lot, 1 set for 2 track days, and the hawk should be good for 4 days at least. More available for me in Canada. But the DTC-60 needs heat, cold friction is just very low.

I am looking to improve my catch can system... I will see. I am working to put 2 catch can in serie, the first with drain to block, and the second to catch oil coming out from the first catch can. Maybe not required, I will see. I prefer to go on the safe side. Quite funny by the way, I purchased 3 types of catch can on amazon, paying between 25 to 40 Can $ for each, and they are the same as supplied on more website at 100 US or more each.

And by the way, and following a comment about my seat belt, I changed it, the new one (not new, but coming from a previously owned DRS car, Speads RS-06). The new one are tighter on their adjustment, the old one were slipping a little bit.

I decided to changed my front splitter. My front Reverie is starting to be quite damaged, years after years. I installed the S3 style splitter supplied by elise-shop. I look better. Since my car is sitting very low, Nitron track single with a very small preload (550# spring), and wheel hub 16mm lower than OEM, and with the splitter (taking 3/8 under the car), I decided to lift the front of the car for street use, I have bump to pass over to access to the street. The car was at 2.25 inchs clearance, move up to 2.75. The mounting shock bracket drilled with 3/8 offset holes, with an effect of 3/4 on the wheel. I added helper spring (was in stock) to run the spring as no preload by around 3/16. I moved the bracket down since my wheel travel was already very small at around 3/4 inch. Now, the 3/4 is more like 1 inch which is not bad at all.

The car have returned to street for the next 2 months before snow coming.
 

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Discussion Starter #85
I am looking to modify my exhaust line to reduce the noise level a little bit. At the track, the sound level is limited to 92 dBa (measured how? Where? With? At which distance?), and I am very close to the limit, and able to overpass it if I am on the cut-off. I am typically at 90-91 dBa, but I reach 94 dBa at cut-off with cold temperature outside and cloudy (not helping for the sound). I am using at the moment a FLOWMASTER PRO SERIE 3" 13016100, which have a dual perforated cone inside. I want to reduce the sound by few dBa without putting more restriction. I found a very short Dynatech 776-06302 straight thru muffler. Supposed to cut by 6 dBa a straight exhaust on big block... based on the blablabla marketing stuff. I am pretty confident that it should work for at least 2 dBa based on my experience.

I am thinking by putting the Dynatech before my Flowmaster in order to increase the volume prior to the Flowmaster cone, adding straight line before and also to remove some heat. But it is also possible to install Dunatech after the Flowmaster, but I think it is not the best option.

At the same time, both muffler will be welded together, and as a unit, installed with V clamp both end for quick change with a spare one. The muffler life is good for around 20 hours on track with my previous boost level and heat.

Someone have an opinion?
 

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Discussion Starter #86
The winter is arrived up here on North. Project for the winter started... many small things to do:

  • Changing the exhaust headers, the actual one is cracked with a quick fix. The heat was too high. For the last track day, I reduced the boost from 14 psi to 11 psi. But with water spray over the intercooler, protection removed for air temp on the ECU, the performance did not change so much. The new headers is already installed, with a new turbo housing on the exhaust side. I will 3Dscan at the job the exhaust pipe after the turbo next week.
  • Water tank for spray: at the end of last summer, I started to test water spray over the intercooler. The jets (2) were only windshield jet, not fancy. The result was not too bad for 5 liters of water for 20 minutes track. I will test different garden type water spray jet. The tank size was an issue... I found a nice drone pesticide tank, a little too big, but it will be great. In progress.
  • Throttle body: I was using a S90racing TB since the K20 swap. The blade is too thin and with the boost, it started to have a bent on it. The idle speed was hard to set. Now, I switched to Shunk2 TB. It look well done, better quality than S90racing. But it was required to modify it to fit my TB command progressive system. Done
  • Noise level: I will try to find a way to reduce the sound level on intake side, and on the exhaust side. The exhaust side will be made with a cartridge with 2 mufflers in-line. In progress.
  • Suspension: Hard to admit, but I started to be slower than in the past (I lost 1 second with a faster car...), maybe because I started to be too old, it was my first assumption... but now maybe I did wrong few moves for the suspension. With the Hoosier tire size I am using, they increase in width, and to limit the interference with the rear fender, I put stiffer springs on my old Nitron Sport shock. The car is not balanced like it was. The shocks were old with 12 years old... I switched to Nitron NTR46 triple, and bigger anti-roll bar from elise parts, with slider adjustment. Done.
  • Catch can: I put 2 catch can in serie, the first with the return to the engine, and the second one vented. The car runs few weeks on the street with that solution. I can see water on the second without any trace of oil. I will see the result next summer. Done.
  • Parking brake: Funny things... with very high disc brake temperature at the track, the plastic bushing into the MC4 Wilwood caliper, they just overheat and leave... now I machined replacement bushing from bronze. Done.
  • I will need to decide the boost level for next summer. At 14 psi with ignition retard for air temperature going high, the exhaust temp is too high for sure. With a broken and repaired headers, with exhaust paste to seal the turbo flange, and no air temperature protection, the exhaust temperature was not too high for sure. Now, I think I will start the next winter with 12.5 psi boost, water spray into the intercooler, and no protection (no retard). Since the compression ratio is low, with the water temp measured on the last 2 years, I really think that I don’t need protection to avoid knocking.
  • I did it last year, I reinforced the rear engine support made by Innovative... I know a guy who broke his support 2 times...
 

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