i already have nitrous and i am playing with that for my launch, 40jet single nozzle

but i have a 2001 4.8l Zr1 cam and pac1218 springs.

im running 20lbs of boost and making 640rwhp on spray and 20lbs

gt45 turbo, 1.05 Div AR.

using megasquirt1 for fuel and MSD6010 for ignition.

i have about 26-28deg in it at 0 vaccum and 15deg in it at 20lbs

i have a 3000 stall and i love it for the street, but man i cant launch this puppy hard because it doesnt get nuts till 4000...

im wondering if you guys have any tricks you are willing to share so i might be able to spool this thing.

MSD box has a 2 step, but only kills ignition to limit revving, it isnt a anti lag or boost building retarding 2 step.

i have tried activating the 2 step and the timing retard 10deg at the same time and it does not help.

if i smash the car WOT on the 6500rpm limiter it does build 8psi haha.

but i cant neutral bomb it from there and hope she stays together.

should i just get the nitrous dialed in or try something else?

thanks

 

Is this an M6 car?

Never mind I just saw you said 3000 stall. I wasn't paying attention.

There are several tricks you can use.

I'm more familiar with the stock pcm and HP tuners though and not the 6 box.

 

With the auto, I would say add timing, not retard it to help boost.

 

ill have to look to make absolutely sure, but i am at about 26deg at 3000 and zero vaccum, what would you recommend, i am also on pumpgas 92 octane till 10psi then 70% meth kicks in.

i dont wanna kick a ringland with throwing some * in there

 

can you share the tricks and i will see if i can integrate them into my setup?

 

here is a 8th mile pass working on my launch with no nitrous, you can see me with the stall as far as it will go, and lower right digital gauge is the boost controller displaying vacuum and boost, it goes to 0 basically and as soon as i leave it goes 1 -2 -3 -4 and starts climbing.

 

What's the specs on the gt45? Is it a eBay gt45 or a actual garret ?
Seems like there is more to be desired from the turbo , also how much of a n20 are you spraying ? 640rwhp seems pretty low for 20psi and n20

 

You can run your timing up into the 30s until the first few psi.

 

Wouldnt a transrake help?

 

That 120+ lsa can't be doing it any good. Something around 206-210 duration, 110~112 lsa would wake it up a bunch in the 3-4K range. A crutch might be to advance the current cam 4~6*.

 

I have heard of quite a few guy creep up on 40 until the first few PSI.

I'm no expert tho. Just relaying what i've seen others talk about.

 

This x2, it needs more exhaust duration and a tighter lsa.

Something like 223/228 .610/.588 114+4 or 223/230 .610/.592 114+3 is what I would use for a small c.i. motor with a bigger turbo.

The tricks I use are timing timing timing until 3-4psi. Once you build 3-4psi usually it will light off. If your not running a transbrake though it's going to be harder, but not impossible.

Are there any spark adder tables that can add to the main timing table in the MSD software?

I don't like adding a bunch of timing to the main table, I'd rather set-up a curve that I like on the main table for part throttle and WOT and then use adder tables that only add timing under certain conditions.

One of the main tricks I use is the AFR spark correction adder table on the stock pcm. Under this table you can have the pcm add timing when the computer commands a certain afr. So when your on the footbrake and the computer commands the afr you want you tell it to add timing when it commands that afr. It will add timing to whatever is already in the main timing table so you don't have a ton of timing in your main table.

I also set up fueling to where the open loop fuel adder table is the only table that controls fueling up to 95-100kpa. After that I let PE take over up to the boost I want to run, then I set the BE as overboost protection. So I will match PE and BE up to say 15psi that I want to run, and then after 15psi I set the BE to some crazy rich number in case the gate fails and it overboosts.

This also allows lean afr transitioning from vacuum into boost which helps on spool up on the footbrake and while driving around on the street plus if you also use the afr spark correction table and add timing at that afr you see on the footbrake you will have the lean afr and added spark working for you.

Depending on the fuel used I will leave the afr spark adder in till 3-4psi sometimes more depending on cam, turbo and octane.

Hope this helps some.

 

I tried it from 28-40 with no difference in spool on a 4.8

bringing it in lean on the tb did way more to help it spool.

 

ebay gt45, im using a 40jet. pretty small shot.

 

i am sure it would, but i doubt it with the small converter and i dont want to install a TB.

 

on pumpgas? i dont want to kick a ringland

 

Try a bigger shot and engage it at like %50 throttle then cut it off at say 6psi. One of my friends used to sit at the line just above idle on the fb and had his 150shot come on at %30, flashed the converter much higher. I know you said you didnt want a tbrake, but i love mine, i leave at about 3-4 psi and its 16psi in a hair over 1 sec. 355cu but t6 turbo.

 

Without a transbrake your going to be very limited. Your video shows how you dont want to stage if you are trying to make it build boost faster. Try a mixture of more timing and 13.0 a/f for the first couple pounds of boost. When you are staging, footbrake the car as hard as you can to get some rpm in the turbo. After you find the sweet spot of what rpm you can comfortably stage and creep the car through the beams you can use the brake petal to trigger a 2 step and that will help it build alittle more boost and allow the process to be consistant. Those changes should help but will probably not make the car leave good without a transbrake. After you prefect that stuff it will be easy to throw the 200 hp pills in it.

 

yeah i only have a 75 shot on her, ill adjust the nitrous to come on sooner, its a microswitch so ill just bend it to come on sooner and then i will also pill her up.

i was gunna go 150shot if i had to thats the max of my nozzle, but i think itll spin by that point, i might be wrong

 

I have hit a ls2 rear mounted c6 with 200 at wot right out of the hole and had the nitrous kit turn off at 10 psi. Worked well on 18'' drag radials.