Jackson Racing SC High-boost Q&A

[industrial]

Originally Posted by CSG Mike

The easiest solution (and perhaps the wisest) is to judiciously use the increased power. If you wouldn't floor it in a Vette in that area, you probably shouldn't with a 370WHP FRS

That's worth repeating. Good ol' foot control! A whole generation of evo/wrx/sti drivers have been ruined by awd driving dynamics.

[Sleepless]

To be clear, I'm talking about lap times on a track.

Yes, I agree about the right foot control, but when one adds a considerable amount of power to a particular chassis, you potentially run into the issue of no being able to put the power down in a way that actually gets the car out of the turn any faster than with the lower power variant. Usually what I see happen is that one cannot fit a wide enough tire in the back to take full advantage of the power.

I should have been more clear. My question is whether or not you can fully take advantage of the added power. My gut says that one needs wider than 255 rear tires and that's what I'm trying to understand.

While I understand that skinny tires (225s) are best for fastest lap with an NA car, but it is not intuitively obvious how that would be true even for a "regular" 300HP JRSC car. Surely, with 300HP, you'd see faster times on wider tires and even wider, at least in the rear, for the high power version.

So, yeah, color me confused.

PS - My "standard" JRSC is being installed in a month so will get a chance to see how I am able to put the power down out of corners shortly... Thx @CSG Mike for all the JRSC info in the past; pushed me in that direction

[MaximeT]

Originally Posted by Sleepless

To be clear, I'm talking about lap times on a track.

Yes, I agree about the right foot control, but when one adds a considerable amount of power to a particular chassis, you potentially run into the issue of no being able to put the power down in a way that actually gets the car out of the turn any faster than with the lower power variant. Usually what I see happen is that one cannot fit a wide enough tire in the back to take full advantage of the power.

I should have been more clear. My question is whether or not you can fully take advantage of the added power. My gut says that one needs wider than 255 rear tires and that's what I'm trying to understand.

While I understand that skinny tires (225s) are best for fastest lap with an NA car, but it is not intuitively obvious how that would be true even for a "regular" 300HP JRSC car. Surely, with 300HP, you'd see faster times on wider tires and even wider, at least in the rear, for the high power version.

So, yeah, color me confused.

PS - My "standard" JRSC is being installed in a month so will get a chance to see how I am able to put the power down out of corners shortly... Thx @CSG Mike for all the JRSC info in the past; pushed me in that direction

I usually check what manufacturer use for street cars at the power level I'm looking for.

If the street car is fast on a racetrack, the tire size should not be too far off.

Like civic type R at 235mm for 320hp FWD.

You could look at Cayman gt4 and Exige V6 tire size.

[Sleepless]

Originally Posted by MaximeT

I usually check what manufacturer use for street cars at the power level I'm looking for.

If the street car is fast on a racetrack, the tire size should not be too far off.

Like civic type R at 235mm for 320hp FWD.

You could look at Cayman gt4 and Exige V6 tire size.

That is precisely my line of thinking!

[Calum]

Originally Posted by MaximeT

I usually check what manufacturer use for street cars at the power level I'm looking for.

If the street car is fast on a racetrack, the tire size should not be too far off.

Like civic type R at 235mm for 320hp FWD.

You could look at Cayman gt4 and Exige V6 tire size.

The GT4 is 245/295. Could we get those in our wheel wells? I'd prefer a square setup anyway,

[CSG Mike]

Originally Posted by Sleepless

To be clear, I'm talking about lap times on a track.

Yes, I agree about the right foot control, but when one adds a considerable amount of power to a particular chassis, you potentially run into the issue of no being able to put the power down in a way that actually gets the car out of the turn any faster than with the lower power variant. Usually what I see happen is that one cannot fit a wide enough tire in the back to take full advantage of the power.

I should have been more clear. My question is whether or not you can fully take advantage of the added power. My gut says that one needs wider than 255 rear tires and that's what I'm trying to understand.

While I understand that skinny tires (225s) are best for fastest lap with an NA car, but it is not intuitively obvious how that would be true even for a "regular" 300HP JRSC car. Surely, with 300HP, you'd see faster times on wider tires and even wider, at least in the rear, for the high power version.

So, yeah, color me confused.

PS - My "standard" JRSC is being installed in a month so will get a chance to see how I am able to put the power down out of corners shortly... Thx @CSG Mike for all the JRSC info in the past; pushed me in that direction

The reason the 225 is still fastest in most instances, is because even with the JRSC, I'm most often power limited, rather than tire grip limited. For example, going into a series of corners, I have to slow down for the first corner; this is the grip limited corner. If I can stay WOT through the remaining corners, both before and after the power change, then these corners are still power limited, even with the increased power.

At Buttonwillow, which is the track we use as our benchmark, only approximately half of the corners are grip limited, and changing to a HB pulley only changes one power limited corner to a grip limited corner, so the skinnier tire still remains faster. Adding additional rotational mass to change that one grip limited corner to a power limited corner, at the cost of slowing the car down at every other power limited corner, still yields a slower net lap time.

[Evil Rocky]

All this is awesome news. I think going to buy my flex fuel kit and then supercharger to install same time. Hopeful this December or January can buy these.

[rAzEn]

If I already have a JRSC and I want to add this on with a 93oct tune are there any more supporting mods I need to get other than the fuel pump, injectors? How bad of a drop can I expect in mpg?

[CSG Mike]

Originally Posted by rAzEn

If I already have a JRSC and I want to add this on with a 93oct tune are there any more supporting mods I need to get other than the fuel pump, injectors? How bad of a drop can I expect in mpg?

I'd expect a minimal drop for street driving speeds; you're only spinning the supercharger about 9% faster, which isn't much at low RPMs.

You'll need a custom tune as well.

[rAzEn]

interesting, what about with e85? Can the stock engine handle that much power? Can I run this set up with stock exhaust? I dont care about being loud, all I have is a catback.

edit- I would get the flex fuel kit for e85

Originally Posted by CSG Mike

I'd expect a minimal drop for street driving speeds; you're only spinning the supercharger about 9% faster, which isn't much at low RPMs.

You'll need a custom tune as well.

[CSG Mike]

Originally Posted by rAzEn

interesting, what about with e85? Can the stock engine handle that much power? Can I run this set up with stock exhaust? I dont care about being loud, all I have is a catback.

edit- I would get the flex fuel kit for e85

Yes, yes, and yes.

We can package all that together for you.

[Ackario]

Hey Mike, i only have 91 octane in my area, would be posible to run safety the high boost polley on stock engine using Water and Methanol Ijection? do you know if someone does and which numbers did he get?
Thanks!