How can I make my turbo spool sooner?

[Jonny00GT]

I have a built 99 Cobra motor with a Master Power T-70 .68 A/R turbo. I starts building boost at 3000rpm...can I change housing, wheel, etc to get it to spool faster? I'd like to start making boost by 2000rpm or 2500 at least. I only needed 12psi to get the power I wanted for the street.

Or, should I just move to a smaller turbo? Will a 61mm or 63mm turbo spool lower in the RPM range?

Thanks!
-Jonny

 

[TRBO VNM]

a smaller turbo will spool faster. but will it offer the power you are looking for? an electronic controller would help spool it faster and a smaller exhaust housing will help, but you will lose some power up top. but that .63 exhaust housing is pretty damn small already.

 

[Blade Runner]

25-50 shot of the juice.........

 

[Modular Racing]

There are a few ways to do it, some easy some not:

Raise engine compression

Run a set of our stage 1 Turbo cams (less overlap uses exhaust gas more efficiently than blowing back into intake- known as reversion)

Decrease turbo Exhaust AR size

Switch to Numerically lower rear end gears

Increase air/fuel ratio at the lower RPM's (a richer mixture creates more exhaust heat and will spool turbo faster)

Increase timing at lower RPM's (will create more power-More power = more exhaust=faster spool

Good Luck, let us know how we can help!

MMR

 

[76mmsaleen]

New ZEX #82218 Turbo Nitrous System

25-75 HP Adjustable



The first nitrous system designed specifically to spool-up turbocharged engines




• Eliminates boost lag for instant turbo power
• Shuts off nitrous once the turbo has spooled-up
• ZEX™ Active Fuel Control™ adjusts fuel enrichment with variations in bottle pressure so that you’re never too rich or too lean
• ZEX™ electronics use the vehicle’s TPS sensor to activate the nitrous system only at wide open throttle
• Adjustable from 25 to 75 hp


Turbos make incredible power on any engine, but the downside is that it takes several seconds for the turbo to build power producing boost. The ZEX™ Turbo Nitrous System eliminates this boost lag by injecting a shot of nitrous when the engine goes to wide open throttle. This nitrous generates additional exhaust volume that spools the turbo up instantly. Once the turbo builds boost, the ZEX™ kit automatically shuts off using the supplied, fully adjustable boost switch.

Along with excellent turbo response, the ZEX™ kit will also provides maximum engine safety and ease of use. The ZEX™ nitrous system uses an advanced technology called Active Fuel Control™. This exclusive ZEX™ technology monitors the nitrous bottle pressure and adjusts the kit’s fuel enrichment so you are never too rich or too lean. Additionally, with patented electronics that monitor your TPS sensor, the ZEX™ kit reliably activates only when you go to wide open throttle.

 

[Modular Racing]

Nitrous of course works also! , but Most racing classes do not allow "dual Power adders"

 

[Trav40111]

Get a smaller turbo... The Master Power stuff has HEAVY internals (compressor/turbine).. Smaller, lighter stuff (and smaller), will spool faster. You don't need a 70mm turbo, unless you're trying to make 800whp.

Travis

 

[Jonny00GT]

I'm more than happy with 500-550...just want the kit to be closer to 2K. What size do you recomend, A/R, etc?

 

[Trav40111]

There are a few ways to do it, some easy some not:

Raise engine compression[/IMG]

Raising the compression ratio does not change the RPM at which the turbo will begin to make boost. Turbines spool up is dictated by Total Mass Flow.. not compression ratio.

However, raising the compression ratio WILL increase transient response.. which means that the time it takes to go from boost onset, to full boost, will be quicker.


Travis

 

[Trav40111]

I'm more than happy with 500-550...just want the kit to be closer to 2K. What size do you recomend, A/R, etc?

If you only want those power levels.. get this turbo..

Precision SC61, with a T4 housing. Good enough for 680 crank HP. Make sure that you get it with a P-trim turbine, and .81 A/R undivided housing. You may even get away with a slightly smaller exhaust housing.. Call up Precision Turbo, and let them know what you need. It shouldn't be more than about 850 bucks for the turbo. This will spool up at about 2k-2500rpm and make 500whp on pump gas.

Travis

 

[Jonny00GT]

Is there a smaller exhaust housing than the .68 A/R for the Master Power? I'm not really looking to buy a whole new turbo. Maybe I can find someone local who will trade, but...

Timing is only set at 11deg right now. Maybe more fuel and timing from 2000+ would help. It kicks in pretty hard at 3K.

 

[Mike@TCI]

Don't go any smaller then the .68 on the turbine side. I would recomend tuning to aid in quicker response, or a different turbo all together. Full boost at 3000RPM is doing well. There are usually trade off's... If you want that super quick response, your going to sacrifice top end, and vise versa. Nitrous does work for getting large turbo's going, so that would be an option.

Im curious... Where are you going to use full boost at 2000RPM? At the track or street, your going to launch at a higher RPM then 2k, and your RPM's will never drop back down anywhere near that range. If your going for that instant tip in torque response of a blower, it won't happen with a turbo.

 

[Jonny00GT]

I don't see full boost at 3000...that's where it starts to make boost. I will try the tuning tricks and see how it work out. Thanks, ya'll!

 

[Alb Cobra]

Hmm i would have thought you would start building boost sooner than that. i have a gt42-76 and i start making boost at around 3k. to make 500-550 that is only around 10-12 psi right? my boost creeps to about 5 psi then seems like it almost instantly hits full boost.

 

[josh2016]

ever think about going twin turbo? they will spool faster than your single

 

[KingCobra10Sec]

You could also get a bigger downpipe and that will help with the spool. At this point I think you have been given every option on increasing spool.

Now will have just have to spend some MONEY to get what you want, because lets face it this is not a cheap hobby.

 

[SIr RicCuS]

You could also get a bigger downpipe and that will help with the spool. At this point I think you have been given every option on increasing spool.

Now will have just have to spend some MONEY to get what you want, because lets face it this is not a cheap hobby.

Amen to that!

 

[Mark@RealStreet]

Is there a smaller exhaust housing than the .68 A/R for the Master Power? I'm not really looking to buy a whole new turbo. Maybe I can find someone local who will trade, but...

Timing is only set at 11deg right now. Maybe more fuel and timing from 2000+ would help. It kicks in pretty hard at 3K.

You can continue to try and rip turbine housing out of it but that's the wrong way to go about it. That's simply changing the angle of attack on the turbine wheel and slightly reducing the volute volume. The heavy turbine and compressor wheel are what has a far greater effect on your spool up. They are the things with the weight/MOI that you are fighting. The housing just changes how the air hits it and reduces efficiency.

ever think about going twin turbo? they will spool faster than your single

That's not necessarily true at all. SOME twins will spool faster than his specific single, and his specific single will spool faster than some twins. It's not nearly that cut and dry.

You could also get a bigger downpipe and that will help with the spool. At this point I think you have been given every option on increasing spool.

Now will have just have to spend some MONEY to get what you want, because lets face it this is not a cheap hobby.

Not necessarily. If he has minimal exhaust pressure (which is probably the case at these low boost levels), then the DP change will do nothing but make the car louder. To make decisions on piping (and housing) sizes you need to have pressure sensors so you can monitor what is actually happening. For example if you had a 1.5" downpipe, then sure a change to a 4" would be great probably, but if you had a 5" dp, do you really think you're picking up anything going to a 6" dp? These are just arbitrary numbers to illustrate that everything is application dependent.

The tuning tricks will have minimal effect. What you MAY find is that tuning your off-boost power better will make the car quicker before the turbo comes online, and possibly make the transition more linear, but the actual boost threshold will not be effected very much.

Plain and simple for a gross change, you need a different turbo. I would definitely suggest a smaller turbine wheel with a large housing over a large turbine wheel with a small housing.