dyno tuning question..

[2+2turbo]

i wasn't sure where to post this , anyways i found out theres a 4wd dynojet behind the shop i work at . AFAIK dynojets are useless for tuning , and crappy dynos overall , the guy who runs the place was telling this guy he can tune his STI on it , is he just blatantly lying? i wouldnt care putting my car on the dyno to see what it does but is there any point to try and tune anything on this? i know i could have searched and came up with a conclusion of my own but im too lazy!

[Stinky]

Dynojets aren't the best dynos but they are still useful. The main drawback to them is that they can't usually hold a steady load and can only really do ramp runs. You can certainly use them to tune but the quality of the tune might not be as good as other dynos.

[88sinZ]

^ what Stinky said, look for a brake-type dyno to fully tune in the entire engine range


main difference between dyno types
1.Inertial*sp
- must have constant acceleration to give a reading, hence most sayings of 3K/RPM PULL
- basic tuning level, good for some conditions though more can be had out of an engine

2. Brake-Type
-can hold certian speeds to calibrate best engine performance at a given RPM (MUCH MORE STREETABLE/RELIABLE & EFFICIENT)
- endless tuning capabiltys given the right hardware, software, datalogging, and tuning capabilitys to boot
- calibrated tune can maximize fuel efficency while crusing and still provide gobs of fuel under WOT performance for big HP numbers

brake type are not as common so you may have to search around, possibly go out of state to get to one

[Firehawk]

The problem with inertial dynos is they don't place enough load on the engine. Maybe the 4wd dyno is better since there are two drums, but I am not familiar with their 4wd dyno. Anyway, someone who tunes to the nth degree on a dynoject (think qyno queens) usually do so for bragging rights and run super lean on the street. I have seen a number of FI cars that were tuned to death on a dyno and blewup on the street. This is why I do all my final tuning on the street under all kinds of loads. I like to tune part throttle driving, not just full thottle.

[2+2turbo]

awesome ! thanks for the response guys!