Whipple: small pulley with 95

[alhazza944]

Hi there

I have question about having smaller pulley for Whipple 3.5xx or smaller .

I read that I have to use e85 with small pulley. Is there any mechanical problem if I use small pulley with 95 octane?

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[Ryan_s550]

No, as long as you have sufficient octane you can run a smaller pulley.

 

[Roh92cp]

I ran a 3.5" with stock headers and cats for a while with 93 octane. When I got an Ngauge and starting watching for knock I found 93 wasn't sufficient. I was seeing positive knock in the upper 3's and sometimes 4. Whipple cal can pull 4 and add 4 so after that out of safety margins. My bet is even with 95 you will see some knock in the positive 2 area but who knows. Catless long tubes help reduce cyl pressure and knock so some can do it safely. Boostane octane enhancer is a great product endorsed by Whipple and 10 oz on 93 octane can make 100 octane on full tank. there are other ways to do it like meth injection for cyl cooling and added octane as well.

 

[SVT-DADDY]

I still need to do a full 7500 log on my 3.5 pulley but initial results look good on 93. Still adding timing to 6000.

As stated above back pressure is a big part of it.

 

[olaosunt]

I still need to do a full 7500 log on my 3.5 pulley but initial results look good on 93. Still adding timing to 6000.

As stated above back pressure is a big part of it.

I assume you are catless.
Are you getting any belt slip?

 

[SVT-DADDY]

Yes catless with conservative timing. From what I can tell that’s a must. No belt slip, didn’t even adjust it dropping from the 3.625 pulley.

Honestly timing on the Whipple tunes I’ve seen is a little more aggressive, not sure the 3.5 would work.

The 2 common denominators for guys that are making it work seem to be catless and after market tune.

 

[alhazza944]

Thank you for your response
What about using 3.75 pulley with 20% lower pulley. Will it be safe way to get Max power using 95 pump gas?

 

[SVT-DADDY]

Not sure, sounds aggressive. There is a boost chart in the 2018 Whipple thread, I'd refer to that.

Thank you for your response
What about using 3.75 pulley with 20% lower pulley. Will it be safe way to get Max power using 95 pump gas?

 

[alhazza944]

So what is Max power can I get with 95?
What about if I have mmr short block , will I be same limitation of power using 95 ?

Thanks

 

[Ruiner46]

95 octane with what rating? Is this 95 RON or 95 (RON+MON)/2? You have to be careful with octane ratings in other countries. I think 95 RON is something like 90 or 91 octane (RON+MON)/2 which is what we use in the USA. With 95 RON, I would not change the pulley to anything smaller. The 20% overdrive pulley change is a big difference, more than a single pulley size change, so that would not be safe.

 

[Burkey]

95 octane with what rating? Is this 95 RON or 95 (RON+MON)/2? You have to be careful with octane ratings in other countries. I think 95 RON is something like 90 or 91 octane (RON+MON)/2 which is what we use in the USA. With 95 RON, I would not change the pulley to anything smaller. The 20% overdrive pulley change is a big difference, more than a single pulley size change, so that would not be safe.

98 RON will “only just” support a 3.625” pulley (Gen 2 Whipple) on an aftermarket tune.

 

[Bluelightning]

So what is Max power can I get with 95?
What about if I have mmr short block , will I be same limitation of power using 95 ?

Thanks

It all depends on the octane level you can get and how your motor responds to it. The 18 is more sensitive to it being 12:1. If you are running a 20% lower you would pretty much need to be on e85 all the time.

 

[markmurfie]

98 RON would be as low as 88 MON to be considered 93 in the USA.

95 RON would be as low as 91 MON to be considered 93 in the USA.

MON is a number that they came up with actually using the fuel in an actual engine. RON is just an educated guess on how it will perform.
I would be cautious with fuels that don't have a RON+MON/2 rating, they can be very good or very bad depending on the QC.

 

[Ruiner46]

98 RON will “only just” support a 3.625” pulley (Gen 2 Whipple) on an aftermarket tune.

I run a 3.625 pulley with 91 (R+M)/2 and was running the Whipple tune until just lately with no issues. I did have to use the octane adjust feature of the whipple tune to reduce WOT timing. It was even a bit conservative with octane adjust, but that might also be because I live at 5000ft elevation.

 

[alhazza944]

Thank you for your respones .

It seems I will be limited of power by using Whipple with pump gas .what if I switch the plan to TT will I face same problem ?

My plan to get whp 1000 on pump gas using sleeved block .is it possible?

Sorry of being ask a lot but I am not mechanical .

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