mtg6486

iTrader: (2)

i have a 98 trans am with an sts kit on it. i bought the mail order tune with their kit but now i want to make sure im getting the most out of it. i put i up on my friends dyno jet 224x and it wouldnt make boost, yet when i street drive it will. is this because its not a loaded dyno or might i have another problem?

robert miller

I have not seen this befor but it sounds like it. only about 50.00 for a few runs try a diff dyno type. Plus get a good tuner you will get more out of it also.

black98ws6ta

iTrader: (77)

Auto or 6 speed? I have had a couple cars that would not make as much boost on the dyno as on the street but the car really should make some boost. If its an auto I would lock the converter and keep it in 3rd gear (1:1).

MY99TAWS6

iTrader: (3)

I have seen tons of turbo cars dynoed on dynojets in the mags. Maybe you had not traction and were just spinning too much..?
I was planning on taking mine to dynojet next season but think the new ones can do both load and no load testing.
The mustangs are ok for tuning and mabye comparing mods but don't like them much. The local one has set theirs like three different ways. First it was supposedly dynojet equivalent since people didn't like low numbers. Then it was normal mustang setting for awhile and then it was how they felt it should be setting.???

Seems to me dynojet is much more consistent.

You did say it boosts on the street so thats weird. Would say maybe boost leak but if it boosts normal psi on the street that does seem wierd.

donnyshane69

iTrader: (8)

I've had mine tuned on a dyno jet and every time my boost is always about 4 to 6 pounds less than what I hit on the street. I have read on other threads that dyno jet rollers doesn't put enough load on the engine. My next tune (in a couple weeks ) will be on a different dyno.

Slowhawk

iTrader: (12)

Non load dyno's are not the best for turbo's but you can work around it.I use to hold the car brakes when first flooring it to load the turbo.

We have a mustang load dyno now and it's 100x's better for turbo tuning.

mtg6486

iTrader: (2)

i first had it dynoed on a mustang about a year ago and she put down 474 hp & 500 tq and with the dyno jet shes only making 360 hp so its not making boost on there. there were no traction issues and i did a boost leak test last week and had no leaks. its auto and the runs were done in 3rd with converter locked. i might try the brake idea

hawk584

iTrader: (1)

i dont trust dyno's. mine was mail order tuned by brian at PCM4Less & put down just over 500@10'ish psi on LEP's dynojet in Vegas. then on the same make and model dynojet in Ut it only put down 430@4-5psi because it wasn't loaded. the dyno graph also show's it dropping off around 4700rpm but actually pulls through the red on the street. dyno's are good for tuning but like any tool it's all in how you use it

SmurfLSX

iTrader: (9)

As the roller was spinning ??? Is it possible to put the brake on the dyno at X% ? I had a turbo supra (single turbo) on our dyno jet and he only made .5 lb more boost on the street.

tahoeryan

iTrader: (2)

Yeah, I can't say for sure since I made so many changes at the same time, but it should've made more power and not less. With the GTS76 on a mustang dyno it made 708 and on a dynojet with the new BWs480 it only made 625 at the same boost. I can definatley tell it's making more power now than before.

Ryan

SmurfLSX

iTrader: (9)

It also takes the car untill over drive to make correct boost. I would post what people say about it on here about that. My buddy with his sts said he'll show you his car on the dyno.

EPP

iTrader: (22)

The DynoJet can't put enough of a load on the turbo, unless they also did some street tuning you really don't know where you're at with detonation, etc. Some shops with DynoJets do their tuning on the street, then put the car on the dyno to get the results. Bob

SmurfLSX

iTrader: (9)

A STS rearmount with a bigger turbo dyno'd fine on the same dyno. I think theres a problem with sts kit if it takes untill overdrive to make full boost.........

hawk584

iTrader: (1)

being an Auto, maybe it was dyno'ed in 2nd or 3rd , which ever it is that's below the ''P,R,N,D''... on an auto

SSPerformance

iTrader: (76)

it was done in 3rd gear..... another auto car with the same STS kit was fine on the dyno made 8psi of boost and held.... no way should it take the car till od to make the correct boost there is no doubt in my mind there is an issue

ssbandit158

iTrader: (3)

I just finished my front mount t67 garrett build the other day. I had It tuned on a dynojet dyno and It wouldnt build boost either, the guys at the shop said for boosted applications you really need a mustang dyno with bigger dyno brakes. I drove it on the street and the boost came in with no problem. My suggestion is either do an all street tune with your tuner or use a mustang dyno. I dont think you have a problem, other than the dyno

moehorsepower

iTrader: (3)

Tuning turbos cars on a non loaded dyno takes a little practice, You do not run the dyno the same way you usually do. I have been tuning turbo cars on non loaded dynos such as a dyno jet with no problems. I.E. 14lbs on the dyno and still 14lbs on the street..

qqwqeqwrqwqtq

I have zero issues with tuning turbo cars on our dynojet. When they come off the dyno they run at the same boost and air fuel ratio on the track or street.

Fwiw here is the approx acceleration rate of my TT Z06 on the dyno and the track (from data logs.)

Dyno- 600-800 rpm/sec (accelerates faster through midrange than high rpm)

Track-

2nd gear- 1600rpm/sec

3rd gear- 800rpm/sec

4th gear- 400rpm/sec

MY99TAWS6

iTrader: (3)

Maybe some of you guys want to share secrets for the dynojet. I plan on taking my car to get it done next season and closest dyno is several hundred miles away so don't want to waste my time.

moehorsepower

iTrader: (3)

No Secret, Most people will ramp up the car to a set RPM then hammer down, Well the Dyno Jet as you know has a large Drum wheel, what you don't want to do is get that wheel rolling up to speed where it is at it basically free spinning and actually gaining a little momentum (Inertia taking over). Kinda of like pushing something heavy, letting it go and it keeps rolling. What I do is get the car up to speed or RPM range that I want "Slowly" say 3000 rpm's then let off the accelerator and let the RPM's start falling, the drum or Dyno looses momentum then at lets say at 2400 RPM you hammer it, so at that point you are going against the inertial of the drum slowing down so this actually provides enough of a load to get the turbos spooled up. Thats what I do and thats what has worked for me...