race gas questions

[j_biggz]

So my question is about adding a couple gallons of race gas when I go to the track this coming weekend. I want to know if there is any dangers / benefits to doing so. We get crap 91 octane out here at the pump and I can pick up some sunco (I believe) that is 110 octane unleaded. My car is mostly stock besides a few mods: exhaust mani, intake, side mount hard pipes, mbc, and a MHI S16g @14psi. Any advice would be great. Thank you in advance

 

[TsiJohn333]

The benefits you will gain from using 110 octane gas is that it will lower your counts on knock (if you have any). The only thing you have to watch out for is that it will kill your catalytic converter.

 

[j_biggz]

So basically adding the higher octane wont be a huge improvment but will help with knock not that I think I have any but if it will help the dsm perform better Im not against it. Im going to leave the boost @14 psi in fear of being at the max for my injectors but Im looking to get the best bench mark I can for this year.

 

[bo0st]

Yeah it may do some cat damage but if you go catless you'll be fine!

 

[TsiJohn333]

Yes, dont go any higher than 14 psi. I wouldn't run it any higher because you would be running extremely close to 100% IDC. MOST people don't like to go over 80% on the fear of boost creep and boost spike therefore going over 100% and hitting fuel cut (maxing out injectors). I personally would keep it around 13 psi just to be on the safe side.

Lets say if you did have some knock, running higher octane (110 oct.) would help eliminate SOME of that knock and give you better timing advance (more power). I believe for every either 2-3 counts of knock, you loose 1 degree of timing.

I suggest getting a datalogger to see if you are running close to 100% injector duty cycle and see if you have any counts of knock. You would be surprised at what you find.

 

[j_biggz]

I thought only leaded fuel was damaging? I am only putting 2 gallons in to I plan on going with a high flow cat later on but as of now its factory.

 

[blkgst97]

At those boost levels just run 91. If you dont have a way to tune and you are not trying push your setup there is no need for that race gas. If you had a way to tune an you could not push your setup past x amount of timing and x afrs then ya race gas is an option, but not with your setup.

 

[j_biggz]

Whats the best logger? I always see people talking about them but I never see anyone mention names or brands. I believe I read on dsm.org via the " wayback machine " that the IDC was at 15-16 psi but I cannot find the link again for the life of me. I currently don't have a wideband and don't have a logger but I want to be safe and also want to run a good time since I am more than likely the only dsm on the strip. got to keep our rep up. Any advice?

 

[TsiJohn333]

I use evoscan and LOVE it. You can log just about anything of it!

Injector duty cycles (IDC) goes by percentage but is related to psi. IDC is basically how much your running your injectors at a certain level of psi. If your running the stock 450cc injectors, than 15 psi would be maxing them out (running 100% IDC). A good comfortable level would be 13psi in your setup without the risk of maxing out your injectors at 80% IDC

On the other hand if you had evo 560cc injectors (of coarse with the supporting fuel mods) they are about 23% bigger than your stock 450's. So running 13psi on those would be running about 57% IDC on those.

Am i making any sense or am i just talking crap haha

 

[blkgst97]

I use ecmlink v3 lite..."I like it alot" dont turn your boost up anymore until you have a way of seeing whats going on inside your engine. We would rather have you reppin with a slower time than blowing up on the track

 

[TsiJohn333]

AMEN to that!

 

[j_biggz]

evoscan? wheres a good place to pick them up? Ive been running at 14 psi for a little bit now and haven't had any problem with fuel cut thus far but I don't want to run to lean and detonate. Ill be doing some work over the winter and should have some tuning accessories by then. Wideband is next on the list (MTX-L). I feel pretty comfortable at 14 psi but thank you for the input. Very good information here and I will run it on the pump gas even though I'm itching to use the 110 octane to see what its like. Cant afford a new motor at the moment. Ill be posting my best times and updating my profile after Friday night. I'm really hoping for a decent low 14 time. I don't have lots of mods so I'm not expecting a huge drop in time but I can say its definitely faster than when I bought it.

 

[TsiJohn333]

This is the cable you want from evoscan.

EvoScan 1.3R USB Datalogging and Reflashing Cable

 

[j_biggz]

So I pick up the cable and the software for my laptop and then I have evoscan on my computer for a reasonable price? Thats whats I was making of what the website said. I would just use ecmlink but I don't have all the funds for that right now. I still have some minor repairs before I go down that road.

 

[TsiJohn333]

Yeah, same here man! I dont have money to be dropping into dsmlink either! but IMO, i bet everyone that uses evoscan loves it. Its reasonable priced and an awesome logger at that!

You just need that cable in the link above and the software on your laptop and PRESTO you got yourself a decent logger!

 

[blkgst97]

So I pick up the cable and the software for my laptop and then I have evoscan on my computer for a reasonable price? Thats whats I was making of what the website said. I would just use ecmlink but I don't have all the funds for that right now. I still have some minor repairs before I go down that road.

Yes, just understand that evo scan is logger, not a tuning program. It is always wise to have a logger to monitor the changes you make to your engine. You just wont be tuning with evoscan alone.

 

[j_biggz]

I understand the difference. The logger is just a way to actually know whats going on inside the motor while Im driving and to help me keep my engine safe but I cannot change anything with it. Kind of like another gauge but this one does them all in one. I eventually plan on getting a WB and ecmlink but for now a logger is better than nothing.

 

[mattasi]

When you going to the strip? Woodburn? I have never been and would love to meet some other DSMer's. Also I was planning to go this summer sometime, so maybe we can cruise together IDK just an idea...

 

[j_biggz]

We have one outside of medford in white city here is a link:
http://www.championraceway.com/2011/Flyers/Lithia Motorsports Friday.htm
If your interested in making the drive down it would be nice to have a fellow dsmer around. I know its a drive but its up to you on that one. Let me know if your going to make it down and Ill give you my cell number so we can meet up. It starts at 6pm I believe. let me know

 

[j_biggz]

Ended up running a 15.6 with my clutch slipping and a bad slave/master cylinder. I think that will be easy to beat by next year. Ill be doing some work this winter on it and getting it ready for some better numbers

 

[Gostlrs]

There was a guy running a basically bone stock GST & he added a few gallons. He was getting better overall times & speed with same reaction times. A few gallons wont hurt at the boost your running

 

[dpun3]

It seems pointless without a tune.

 

[j_biggz]

I might make it back this season to test it but I'm not sure with an up comming surgery I have. Ill be fixing the slave and master cylinders and see how shes running after that. I'm looking to get down to the 12s but its not going to happen this year. That's my goal long term and it shouldn't be out of my reach. Slicks would probably help a lot right now but I'm on a budget untill after my surgery. Thanks for all the info everyone.

 

[ALLOUT CL55]

Definitely tune the bad boy...

 

[Brian O Conner]

It is illegal but I would take off your catalac converter. Why, because you would gain hp and more mpg. Also Using good oil with your car. Oil with Zinc like Brad penn or Royal Purple you will see some power with your 110 Octane. For minor Speed results get better tires. I believe right now Michelin S2 sport tires are some really good ones for the street. Good traction and weight reduction will allow you to see some speed without a whole lot of spending. Anyways good luck man.