D1SC max whp on e85?

[15GTPP]

I was told 4.88 is the standard pulley because anything bigger won't clear the hood. That's what PC told me over the phone.

I thought that too but I've been trying to get a tune through a new tuner and he's telling me the 4.88 pulley is too much for pump gas. He says he has tuned plenty of 5" d1 kits and is advising me to move up to a 5" for 91. Yet there are some people with the 4.5 pulley on pump gas. He's advising me to switch to e85 with the 4.88 pulley.

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[donmcgowen]

I thought that too but I've been trying to get a tune through Aed and he's telling me the 4.88 pulley is too much for pump gas. He says he has tuned plenty of 5" d1 kits and is advising me to move up to a 5" for 91. Yet there are some people with the 4.5 pulley on pump gas. He's advising me to switch to e85 with the 4.88 pulley.

Procharger and Lund told me to go with 4.88 and that would get me 10-12# of boost. I'm making 10#. Procharger also told me a bigger pulley might have clearance issues. Anyway 5" gonna get you 8# boost at most. I'm ordering the 4.63" pulley. Trying for 13-14# boost.

 

[Jay-rod427]

If you're needing that large of a pulley to keep boost, or tune issues under control you should've never bought the D1...

 

[15GTPP]

No issues with keeping boost or tune issues here. I'm hitting around 12psi with my 4.88 and put down good numbers. Only reason I'm talking to a new tuner is because I just purchased a boss intake and need a retune. Getting an update from Ken nowadays is almost impossible. I've been asking for a update since May 21st. He's a really busy guy.

 

[3beeps]

No issues with keeping boost or tune issues here. I'm hitting around 12psi with my 4.88 and put down good numbers. Only reason I'm talking to a new tuner is because I just purchased a boss intake and need a retune. Getting an update from Ken nowadays is almost impossible. I've been asking for a update since May 21st. He's a really busy guy.

That is way too long to wait for a tune update. :tsk:

 

[15GTPP]

That is way too long to wait for a tune update. :tsk:

Tell me about it.

Just added you on IG. :cheers:

 

[MyLilPony]

what are you guys revving to that you are measuring your boost levels at? with the 4.75 and headers never saw over 10/11psi at 7750rpm? 8 or 9 psi at 7k, I am assuming you are revving pretty low based on the boost numbers you are seeing.

As for boost on pump, I've ran as high as 14psi on 93 so 10 to 11 on 91 I would imagine is just fine.

 

[donmcgowen]

what are you guys revving to that you are measuring your boost levels at? with the 4.75 and headers never saw over 10/11psi at 7750rpm? 8 or 9 psi at 7k, I am assuming you are revving pretty low based on the boost numbers you are seeing.

As for boost on pump, I've ran as high as 14psi on 93 so 10 to 11 on 91 I would imagine is just fine.

I'm using my built in boost gauge so not sure of accuracy. Taking a quick peek around 7k I'm seeing 10# or very close to it. I was hoping to hit 12# with this pulley. I would see no reason to go any bigger than 4.88 otherwise what's the point of a D1.

 

[z06psi]

4.5" 7750 and 12 psi here. Cat deletes and Sniper though.

I have a 4" sitting here though.

 

[3beeps]

My logs show 11 PSI on the dyno in 5th gear and 13 PSI on the street in 3rd gear using my Lund boost box. 4.88 pulley w/ catless longtubes (THIS WAS WITH THE STOCK MANIFOLD, NOT THE BOSS!).

 

[donmcgowen]

4.5" 7750 and 12 psi here. Cat deletes and Sniper though.

I have a 4" sitting here though.

Damn, only 12psi with the 4.5" and I was looking at the 4.63". Now I'm not sure because obviously boost is different at different elevations. I guess I'll start with the 4.63" and see where I'm at.

 

[15GTPP]

Yeah idk why but this tuner is refusing to tune me on 91 with a 4.88 pulley and boss intake manifold.:frusty: He says the boss manifold does not lower boost.

 

[donmcgowen]

What does a 4.88 pulley have to do with tuning? Did you ask him why?

 

[15GTPP]

Claims I am pushing to much airflow with the d1 for pump gas and recommended switching to e85. He said he tuned a d1 with 5" pulley and it saw 15psi @ 7600rpm. No way am I seeing anywhere near that at my elevation though. I'm at 4000ft above sea level and he's at sea level but he still refused saying I'll see too much boost.

 

[Crackerjack17]

Won't cam timing effect boost levels? And isn't the boost # arbitrary? Because your spinning the blower X speed and it should flow X cfm. And everybody has different exhaust setups, so boost numbers are going to vary.

Fyi- I hit 10.4 @ 7500 and then installed catless long tubes, no change in tune boost went to 9.8 @ 7500. Lund boost box. And car lost 30hp across the board. Curves look identical but less power. Lol. Made tune revisions and I haven't re-dyno'd but power is back.

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