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robertcope

January 2020 Member Days

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1 hour ago, Matt93SE said:

Yeah, that was me in the white one.  Louie was playing around in the black/orange/white one just to feel it out for a customer.  he only ran a single session since it was low on fuel and he just needed to check it out.

Mine has the Radium surge tank in it and I can run the tank nearly dry..   but when running 100 octane, my day didn't last long at $45/session in fuel!

100 octane! super high compresssion? Lots of boost? I like my Radium surge setup for sure. It's basically a necessity on e85 😉 

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Jackson racing (Rotrex) supercharger kit on the car w/ ECUTEK driving it.

Jackson racing manual says the car is fine for daily driving on 91+ octane with stock internals, but when tracking the car you need to use at least 96 octane to keep reliability.  (it says min 50% mix of 100octane race fuel  w/91 or better, and DO NOT use octane boosters to get there.)  so I figure in winter I can maybe get away with a 50% mix of 93 and 100, but for summer I'll run straight 100 to make sure it doesn't die.

I was hoping a little de-tuning of the ECU might allow the car to run 93 octane all the time so I could reduce running expenses and play w/ enduros, but that doesn't seem likely now that I've bought the car and done more research. 😞

 

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21 minutes ago, Matt93SE said:

Jackson racing (Rotrex) supercharger kit on the car w/ ECUTEK driving it.

Jackson racing manual says the car is fine for daily driving on 91+ octane with stock internals, but when tracking the car you need to use at least 96 octane to keep reliability.  (it says min 50% mix of 100octane race fuel  w/91 or better, and DO NOT use octane boosters to get there.)  so I figure in winter I can maybe get away with a 50% mix of 93 and 100, but for summer I'll run straight 100 to make sure it doesn't die.

I was hoping a little de-tuning of the ECU might allow the car to run 93 octane all the time so I could reduce running expenses and play w/ enduros, but that doesn't seem likely now that I've bought the car and done more research. 😞

We should talk somemore if you have time / are willing ...the final piece to my performance puzzle being contemplated right now is a reliable power strategy. Current frontrunner is a supercharger...a Rotrex C38 JRSC kit. 

Plan was the low boost pulley to get to ~240 peak whp, and to run e85 for it's 105+ equivalent octance rating and ... voila ? Not so? Are you on stock internals, or does yours have a lower static compression ratio piston set in there? 12.5: 1 from the factory scares me when mixing boost into the equation...thus the need to be extra knock resistant with the higher octane? Factory ECU or a more powerful replacement? 

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3 hours ago, Solo_S14 said:

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You sort out how I keep ABS with ^^^ installed and I'd be way more convinced. Thats the last of the original cars electronics I'd need to keep i think...

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On 1/15/2020 at 2:50 PM, joesurf79 said:

We should talk somemore if you have time / are willing ...the final piece to my performance puzzle being contemplated right now is a reliable power strategy. Current frontrunner is a supercharger...a Rotrex C38 JRSC kit. 

Plan was the low boost pulley to get to ~240 peak whp, and to run e85 for it's 105+ equivalent octance rating and ... voila ? Not so? Are you on stock internals, or does yours have a lower static compression ratio piston set in there? 12.5: 1 from the factory scares me when mixing boost into the equation...thus the need to be extra knock resistant with the higher octane? Factory ECU or a more powerful replacement? 

Without knowing the details of your motor Your main issue is not so much your static compression. It is the dynamic. Happy to chat about it at next available instance. I am running a 4.2 V8 supercharged on my RS4 (stock is N/A) with 11.5 CR static. Rule of thumb though is you can run without too much hassle 5psi without intercooler and a bit more (8-9 with inter cooler). Quality of fuel + reduced intake temps are your friends and you can always add a heat exchanger cooled by the ac Freon to keep intake really low...just fyi. We are running 12psi safely without any issue so far.

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On 1/18/2020 at 8:24 PM, Paladin said:

Without knowing the details of your motor Your main issue is not so much your static compression. It is the dynamic. Happy to chat about it at next available instance. I am running a 4.2 V8 supercharged on my RS4 (stock is N/A) with 11.5 CR static. Rule of thumb though is you can run without too much hassle 5psi without intercooler and a bit more (8-9 with inter cooler). Quality of fuel + reduced intake temps are your friends and you can always add a heat exchanger cooled by the ac Freon to keep intake really low...just fyi. We are running 12psi safely without any issue so far.

I'll PM you - I need the information you offer sir! 

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On 1/15/2020 at 7:08 PM, joesurf79 said:

You sort out how I keep ABS with ^^^ installed and I'd be way more convinced. Thats the last of the original cars electronics I'd need to keep i think...

Brakes are for pussies..  

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14 hours ago, Captain Buddha said:

ABS? In a race car? Sacrilege!!

yeah yeah, I know. I should put the security blanket out to pasture. It would save weight too without the pump, etc.

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On 1/15/2020 at 7:08 PM, joesurf79 said:

You sort out how I keep ABS with ^^^ installed and I'd be way more convinced. Thats the last of the original cars electronics I'd need to keep i think...

who needs abs? see thats what I like about my cobra.... no aids.  no power reduction no abs no traction control just pure pedal brake and clutch.  

 

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32 minutes ago, Talley said:

who needs abs? see thats what I like about my cobra.... no aids.  no power reduction no abs no traction control just pure pedal brake and clutch.  

 

ABS is great to keep you from flat spotting a tire and costing you replacement costs and track time. Sure, you can get by without it and you shouldn't need it, but when you screw up or shit happens, it's nice to have and can save you some frustration and/or money. Plus, you can threshold brake with an ABS equipped car the only differences are the weight of the system and the safety net it provides. I'm keeping mine.

Also, not to be mean but you aren't anywhere near the limits in your Cobra. If you had some driver aids you might feel more comfortable pushing a little harder and picking up some speed. Then, when you've learned a thing or two you could turn them off (hell, you can even disable ABS in most cars by pulling a fuse).

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Sam - go wrap yourself in bubble wrap...LOL...you shouldn't need it...but it's nice to have...

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28 minutes ago, BRZ4Science said:

If you had some driver aids you might feel more comfortable pushing a little harder and picking up some speed. Then, when you've learned a thing or two you could turn them off (hell, you can even disable ABS in most cars by pulling a fuse).

Great advice. When I took my FWD platform out the other weekend for giggles I noticed I was driving behind the car instead of in front of it for the first session. I switched on some of the aids, went back out and was immediately slapped on the wrist for what I was asking the car to do (incorrectly). It allowed my brain to rewire itself and get back into the correct mindset for the car. Soon after, they were turned back off and the time gains were substantial. Always a great learning tool + safety net.

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1 hour ago, BRZ4Science said:

ABS is great to keep you from flat spotting a tire and costing you replacement costs and track time. Sure, you can get by without it and you shouldn't need it, but when you screw up or shit happens, it's nice to have and can save you some frustration and/or money. Plus, you can threshold brake with an ABS equipped car the only differences are the weight of the system and the safety net it provides. I'm keeping mine.

Also, not to be mean but you aren't anywhere near the limits in your Cobra. If you had some driver aids you might feel more comfortable pushing a little harder and picking up some speed. Then, when you've learned a thing or two you could turn them off (hell, you can even disable ABS in most cars by pulling a fuse).

Hey I completely agree with ya but the abs is not the contributor to my slowness. My slowness (in my opinion) is simply my brain is not used to corner entry speed.  abs is not what making me slow it's the speed in the corners that scares me (|) lol...  Hell I go 120+ almost every day in my tuned truck but you wouldn't catch me doing that in a corner.  Well now that I have a machine that is capable it's a new feeling trying to. (remember I'm just a drag racer turned hdpe driver)

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1 hour ago, BRZ4Science said:

ABS is great to keep you from flat spotting a tire and costing you replacement costs and track time. Sure, you can get by without it and you shouldn't need it, but when you screw up or shit happens, it's nice to have and can save you some frustration and/or money. Plus, you can threshold brake with an ABS equipped car the only differences are the weight of the system and the safety net it provides. I'm keeping mine.

Also, not to be mean but you aren't anywhere near the limits in your Cobra. If you had some driver aids you might feel more comfortable pushing a little harder and picking up some speed. Then, when you've learned a thing or two you could turn them off (hell, you can even disable ABS in most cars by pulling a fuse).

This ^^^

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2 hours ago, Talley said:

who needs abs? see thats what I like about my cobra.... no aids.  no power reduction no abs no traction control just pure pedal brake and clutch.  

You dont NEED it yet, but I am willing to be if you really start pushing that cobra on track, the WANT of it will be there for a few laps 😂

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1 hour ago, joesurf79 said:

You dont NEED it yet, but I am willing to be if you really start pushing that cobra on track, the WANT of it will be there for a few laps 😂

slow progress is still progress lol.  I'm not in any race here guys.  Just wanna go around the track yelling WEEEEEEEE into my instructors mic giving point-bys to mini coopers

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If you brake correctly (threshold braking followed by trail braking) ABS is not an issue...brake hardest first and then trail off right as you are turning in, even with some overlap depending on the car, corner, etc. What I drive (TA2 and ASA/GTA cars) has manual brakes..I left foot brake and JAM/MASH on the pedal (900-1,200 psi is normal for a HARD brake)...you don't get a lock up at 150, 160, 170++.....

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On 1/15/2020 at 2:50 PM, joesurf79 said:

We should talk somemore if you have time / are willing ...the final piece to my performance puzzle being contemplated right now is a reliable power strategy. Current frontrunner is a supercharger...a Rotrex C38 JRSC kit. 

Plan was the low boost pulley to get to ~240 peak whp, and to run e85 for it's 105+ equivalent octance rating and ... voila ? Not so? Are you on stock internals, or does yours have a lower static compression ratio piston set in there? 12.5: 1 from the factory scares me when mixing boost into the equation...thus the need to be extra knock resistant with the higher octane? Factory ECU or a more powerful replacement? 

Unfortunately, I know next to nothing about it yet! LOL   Just what the previous owner's mechanic told me when I bought the car and picked it up.   I did the one play day at MSRH a few weeks ago, and it's been sitting in the trailer since. 😞

For SCCA, there is a very short list of aftermarket boost devices, and the Jackson Racing (Rotrex) and Edelbrock kits are in there with specifics about the pulley diameter, etc..  I must admit I haven't read the rulebook and trust the car to be legal since both the owner and mechanic are meticulous about staying 100% within the ruleset.   This car has also been on the podium at runoffs a couple times, so it's been through the eyes of all the tech guys and passed muster.   thus I'm 100% confident that the setup doesn't exceed what's in the rulebook.

Engine internals are stock and will stay stock.  I'm told that's actually the trick to keeping these things reliable.  as soon as you open one up and start messing with it trying to get 'just a little more', you get less reliability and stop finishing races.  The World Challenge folks kept opening them up and adding cams, jacking w/ compression, etc trying to get more power and all they did was blow them up.  Went back to stock engines and kept the weight down on them and did well.

computer is an ECUTEK, but that's all I know- don't know version or type or anything like that.  Supposedly Jackson racing tuned the engine and nobody's touched it since.  the guy I bought it from doesn't even have the software to do it, but I called Jackson and they insisted it was changed since they sold it.   I'm now looking for someone around Houston that is qualified to tune this thing without blowing it up.

Based on the JRSC manual, 100 octane on track is highly recommended and at least 96 octane is required to keep the thing alive during longer stints on the power.  street use doesn't abuse the engine as bad, so you can get away with 91+ octane on the street.

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As far as the tuning and fuel.  My cobra is seeing 14-15psi with stock 8.5cr and I use pump gas.  For the track I mix 5 gallons of 100 octane to 15 gallons of 93. I have a 20 gallon cell. Car makes 580rwhp on 93 with no additional timing for the track the added octane is just insurance.  

 

I have an aluminum teksid block and plan to do a build with 10.5 pistons and was told I can still run the 15psi on pump gas and that my power would only increase to 600-605ish. 

Why not switch to e85?

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26 minutes ago, Talley said:

Why not switch to e85?

This is my question as well. From what I've read / heard (credible sources or not, who knows) the equivalent octane rating of e85 is approx 105. It's 30% lower in BTU content so you have to run a ton more of it (needing bigger pumps, injectors, resistant fuel lines, etc). And its hygroscopic like brake fluid, so it pulls water from the atmosphere, and is highly corrosive to susceptible metals. But for a toy car under boost that you can nearly run dry and park with some ethanol stabilizer or some 96 octane in the tank as insurance - why not?

I run e85 in the BRZ NA and the flex fuel tune i have allows any mix from 100% 93 to 100% e85. You can tell there's more power on e85. I guess its allowing more radical ignition timing?

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