Turbos making less power down low?

[subatoy]

Theres been talk about turbo kits making less power down the RPM range before any boost kicks in. I've notice that most Dyno graphs only show past 3k rpm. I hate rumors and when people say "but he said" and "the other guy said"

I'm hoping the turbo tunners will answer this question once and for all.

[WolfsFang]

it all depends on the turbo size, where its placed, piping, and alot of other stuff. But their is a chance of some loss of power due to no boost down low. I would not worry since 3k rpm is really low for our cars, infact if boost kicks in at 3k then thats great.

[mact]

Dynos starting at 3k RPM does not mean the car doesn't make any power below 3k RPM. That's just when they happen to start measuring.

[DriftEightSix]

would love to see a pull that shows stock vs turbo from 0 rpm...

Can this be done?

[dboz]

With a quick high revving engine, 3k RPM is nothing. I think that is actually pretty quick.

My EVO X does not really "kick in" until about 3-3500 RPM either. Feels plenty fast but lack of low end grunt does hurt out of the hole.

Torque is the big thing to look at, hot HP.

[EvoFanatic]

Originally Posted by dboz

With a quick high revving engine, 3k RPM is nothing. I think that is actually pretty quick.

My EVO X does not really "kick in" until about 3-3500 RPM either. Feels plenty fast but lack of low end grunt does hurt out of the hole.

Torque is the big thing to look at, hot HP.

This! Everyone always forgets that Torque is what gets you going fast (acceleration) and HP is what lets you be fast (top speed) if that makes sense. For example, a car that runs a quick 1/4 will have lots of torque but not necessarily a lot of HP. However, a car that can run 200 mph will have a lot of HP but no necessarily a lot of torque.

[jdzumwalt]

Torque is what moves mass period. Hence the reason my dodge cummins make 650 ftlbs of torque and will pull the hell out of my trailer from stand still. Disconnect the trailer step on the gas truck barley picks up any acceleration.

Have you driven this car the motor doesn't come on till after 3000 rpm whats the point of a turbo spooling up if the engine isn't breathing yet?

When I set my turbo motors up I always want full boost by torque peek. I would say the kit's are doing this quite nicely.

Our cars are super light they don't need gobs of torque like a heavy car does to get the mass moving. The main reason the torque figures are down is due to the head design and the high compression. I would much rather have this bad ass tuned head than some small port high torque non revving head. Kuttos to Yamaha for building us a badass head.

[dsgerbc]

That's because most turbocharged setups I've seen so far - are essentially a competition by tuning shops for top HP. So they pretty much don't care about torque down low, cause it will hurt the end-result HP number. Very rarely will a tuner produce a DD-friendly turbo setup on his/her own, unless specifically paid by the customer to research that.

Why current setups lose torque in the low RPM range - I don't know. The "dyno starts at 3k" is a lame excuse. Dyno of a stock car also starts at 3k generally reads higher.

2-4k RPM range is imporant for DDing these cars.

PS: "moving mass" is work. Amount of work per second = HP.

[wootwoot]

Originally Posted by dsgerbc

That's because most turbocharged setups I've seen so far - are essentially a competition by tuning shops for top HP. So they pretty much don't care about torque down low, cause it will hurt the end-result HP number. Very rarely will a tuner produce a DD-friendly turbo setup on his/her own, unless specifically paid by the customer to research that.

Why current setups lose torque in the low RPM range - I don't know. The "dyno starts at 3k" is a lame excuse. Dyno of a stock car also starts at 3k generally reads higher.

2-4k RPM range is imporant for DDing these cars.

PS: "moving mass" is work. Amount of work per second = HP.

I disagree. I know that the AP kit was designed to spool a bit latter and have a bit less at the low end (not over stock but over what a different turbo would have made) because Don was worried about things breaking if there was to much low end gain. I read that on here somewhere anyway... Seems like the turbo was selected with the daily driver in mind.

On another front, these shops know that most people will not be turbo charging their FRS. And even those that do are not building race cars but rather fast street cars. From what I have seen they build their products with this in mind. The "most HP" competition you see is just marketing and a way to test the motor as well as their products.

My 2 cents.

[dsgerbc]

Originally Posted by wootwoot

Don was worried about things breaking if there was to much low end gain. I read that on here somewhere anyway...

Dynos I've seen - are producing less in the <3k RPM range. Not sure how the concern of something braking is relevant there. If it's just the dyno start at 2.5k that's affecting things - then they have to start it sooner. 3k is 6th gear @70mph. If there is a nice torque gain there, I'm sure people too lazy to shift in traffic will appreciate it.

[JoeBoxer]

That's one thing i've noticed as well torque and hp figures in the low rpm's aren't impressive. Thats why i'm hoping a smaller turbo or supercharger kit will come out thats got more power early in the rev range i don't care about 300hp at 7k rpm

[chulooz]

Originally Posted by jdzumwalt

Torque is what moves mass period. Hence the reason my doge cummins make 650 ftlbs of torque and will pull the hell out of my trailer from stand still. Disconnect the trailer step on the gas truck barley picks up any acceleration.

Have you driven this car the motor doesn't come on till after 3000 rpm whats the point of a turbo spooling up if the engine isn't breathing yet?

When I set my turbo motors up I always want full boost by torque peek. I would say the kit's are doing this quite nicely.

Our cars are super light they don't need gobs of torque like a heavy car does to get the mass moving. The main reason the torque figures are down is due to the head design and the high compression. I would much rather have this bad ass tuned head than some small port high torque non revving head. Kuttos to Yamaha for building us a badass head.

Yamaha had no involvment on the heads of Subaru's FA20, Toyota's direct and port injection (D4-S) was their contibution.


And as for turbo power down low? Check out the FB20 DIT in the JDM legacy (295hp 295tq) :


seeing that in a BRZ(with a tune!)

[eclipsed]

Originally Posted by JoeBoxer

That's one thing i've noticed as well torque and hp figures in the low rpm's aren't impressive. Thats why i'm hoping a smaller turbo or supercharger kit will come out thats got more power early in the rev range i don't care about 300hp at 7k rpm

Hoping for a roots type SC kit or fast spooling turbo kit as well. Currently living at extremely high elevation (over 6000 ft.), and with the consequent power loss this car is a complete dog in the low end.

[JoeBoxer]

Originally Posted by chulooz

Yamaha had no involvment on the heads of Subaru's FA20, Toyota's direct and port injection (D4-S) was their contibution.


And as for turbo power down low? Check out the FB20 DIT in the JDM legacy (295hp 295tq) :


seeing that in a BRZ(with a tune!)

not sure what newton meters converts to lb ft but i like that flat torque curve.