Sprintex 335 Testing & Progress

[brianhj]

Originally Posted by dwx

E85 doesn't really have an octane equivalent. It will make as much power and be almost as knock resistant as running 116+ octane gas like VP Import or Q16, and is much much cheaper. You just need the right pump/injectors/etc. since you will be using more fuel with E85. There is a reason the highest HP drag cars run on pure methanol and not gasoline.

I would never run a 335 or turbo over 12PSI on anything but E50+ built engine or not.

>E85 doesn't have an octane equivalent
>It has the equivalent of 116 octane gas

Oh ok

[sw20kosh]

Saying E85 is equivalent to 116 octane means it has an octane equivalent...

[murdoc]

I think he or she was trying to explain that e85 will usually be around 94-96 octane, but the cooling properties of alcohol and the fact that you're spraying more fuel will give you knock resistance similar to race gas.

[Xero-Limit]

Originally Posted by dwx

E85 doesn't really have an octane equivalent. It will make as much power and be almost as knock resistant as running 116+ octane gas like VP Import or Q16, and is much much cheaper. You just need the right pump/injectors/etc. since you will be using more fuel with E85. There is a reason the highest HP drag cars run on pure methanol and not gasoline.

I would never run a 335 or turbo over 12PSI on anything but E50+ built engine or not.

That does have a good deal of merit, but the "safe boost limit" I think is still vague. We've installed and tuned a bunch of kraftwerks C38 kits which spin to 15 psi. No issues on them so far, many of which run pump gas. I've had several customers overboost to 17+ psi on bad wastegate turbo setups, all have lived with our failsafe using reduced timings.

But if you were to ask me two years ago what the safe boost level is, I'd probably say 7 psi then. What we're finding is that with the DI system at 17 psi and pump gas on the 12.5:1 CR we're running about the same ignition timing that we ran on the 10.5:1 MX5s at 9 psi. So that tells me we have room to go before autoignition. So we can keep cranking the boost up and do fine by retarding the timing to keep the pressure down on the ring lands and the rods/bearings. If I didn't think that was the case I wouldn't have run this on pump gas, but as is the case we did fine through several WOT runs in 4th gear.

That is not to say I would recommend it, but I think it can be done. With e40 and up it is a completely different animal though, and on e70+ we can hit the same timings we were running on the 210 kit at 12 psi. So the motor definitely can take it on e85.

Another very important point is that this is a supercharger. If you want to run 10 psi on pump and 17 psi on e85, it is as simple as making a map mode that limits throttle with EcuTek. That is a VERY effective way to control boost, and we've used it on poorly put together turbo systems that creep. Add in as much valve overlap as you can to spit fresh air out, and then close the throttle/kill ignition timing. Lots of backend work, but completely transparent to the driver. Simply a low/high power map when the fuel is right.

[xwd]

Originally Posted by brianhj

>E85 doesn't have an octane equivalent
>It has the equivalent of 116 octane gas

Oh ok

Learn to read.

It will make as much power and be almost as knock resistant as running 116+ octane gas like VP Import or Q16, and is much much cheaper.

Where did I say it had an octane rating? There are a lot of other differences between the two...

[brianhj]

It will make as much power and be almost as knock resistant as running 116+ octane gas

That is equivalent to an octane rating.

If it doesn't have an equivalent octane rating, then don't say it is almost as knock resistant as running <octane rating>.

[brianhj]

Originally Posted by sw20kosh

Saying E85 is equivalent to 116 octane means it has an octane equivalent...

Fucking this

[xwd]

Originally Posted by brianhj

That is equivalent to an octane rating.

If it doesn't have an equivalent octane rating, then don't say it is almost as knock resistant as running <octane rating>.

It doesn't have an octane rating measured like gasoline does. Octane rating is talking about something very specific which doesn't capture the benefits of E85 or something like methanol. It's also not as forgiving as running 116+ octane gas in regards to tuning because its "octane" rating is not equivalent to 116. Get it?

Anyways, I'd like to see some dyno plots with the 335 on whatever is in the tank, preferably E85.

[Calum]

Diesel doesn't have an octane rating either, it has a cetane rating. Like methanol, cetane has no conversion to octane.

[sw20kosh]

Originally Posted by dwx

Anyways, I'd like to see some dyno plots with the 335 on whatever is in the tank, preferably E85.

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page 2 post 40..

[xwd]

Originally Posted by sw20kosh

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page 2 post 40..

Haha oops. That's the last post on the first page for me so I missed it. I don't use the noobie settings.

[D K]

What kind of power are you seeing on E85 with this combo?

Originally Posted by moto-mike

That does have a good deal of merit, but the "safe boost limit" I think is still vague. We've installed and tuned a bunch of kraftwerks C38 kits which spin to 15 psi.

[doberman8u]

Hi Mike, what clutch do you have in this setup? Is it holding the torque well?

[2much]

Do we expect this system to run well on 91 octane?

I am very interested in either this or OFT350 if that comes out... and 91octane will be the biggest factor