im lost why is this thing not making power what are your thoughts

[SprinterTRD]

Like I said before Its probably flat because the TVIS has been removed or is not working, We need a answer on this.

TVIS makes a big differance to how a bigport feels midrange

[munki]

It has blacktop itb so id assume tvis is removed.

[Jimmee1990]

It is supposed to have Toda high comp pistons and ITB's, TVIS would be a massive restriction as long as it has the right cams which he's unsure of.

[SprinterTRD]

[Jimmee1990]

His engine is flat everywhere though, not just in the mid-range where TVIS makes a difference. With the specs it's supposed to have, he should be making 140-150hp at the wheels and a lot more midrange than he has now. I can't see how adding TVIS would help in the slightest in this instance?

The last engine I built was a standard small-port bottom end with a bit shaved off the deck, a shaved big-port head, some mild cams and a good clean up and de-dagging of the ports and chambers. Made more power and torque everywhere on the engine dyno with the TVIS butterflies and shafts removed and the holes filled than when it was working testing them back to back as I had two plates to try. Was a standard MAP big-port ECU as well so zero correction for it either way. On a standard engine it works how it's supposed to, anything more than a mild set of cams, a little extra comp and some porting and it becomes redundant.

At the end of the day all of this is moot, as I don't think your engine is as it's supposed to be. Only way to know for sure is to pull the sump off and see, or just be content to drive it as it is now because you won't be able to pull much more out of just a tune.

[SprinterTRD]

With that setup its not going to make 140 to 150 HP.

If he wants more horsepower, remove his reasonable 50 series tires (just guessing about this) and replace the rear tires with elcheepo tires and pump them up to 40 pounds, there is guaranteed HP gain there!

However he is complaining that the engine is flat, which is lack of midrange torque

If the tuner has done it correctly A simple check would be to look at his fuel map in his ECU. If the fuel values from say 60% throttle to 100% throttle don't change much under 4Krpm then there is a air flow issue.

What I mean by this is look at the fuel values between 60% and 100% throttle in the 3000 rpm column ( assuming it is mapped against throttle position ) if there is a reasonable change in fuel numbers the there is a reasonable air flow change based on the throttle plate angle this is good, if the numbers don't change much then there is not much change in airflow which is bad . This means there would be little difference driving the car at 60% compared to 100%

BTW this is a classic problem with having too much throttle area.

I can safely say and proven on a engine dyno that TVIS makes a big difference in mid range torque even on a engine with 323/11mm lift cams with standard inlet manifold such as a GpA engine.

The small port 16V head works better because it has a smaller port area and has better air speed. The 20V head works even better because of the small port area and larger valve area and better port angle.

With that much port area it may be an advantage using E85 and reaping the gains from a slower burning fuel. He will need to retune the engine.

[slider4life]

Its a good adaport and has been matched to head and the throttle bodies

no the motor dose not have tvis only got the quads and the adaptor for the head

ill get so more pics up soon and get a pic of the cam gears for you guys

[slider4life]

So it seems when he says set at 10 and 2 he mean intake cam set 3deg retarded and exhaust cam 3 deg advanced here is a picture

And now i've been told were to find the sizes here is a pic there 288 deg cams intake and exhaust it says top and 288

[slider4life]

So my next thing on my list is get the cam timing checked make sure that is right. I don't want to stuff that up so ill have to get a mate to help me with that.

[slider4life]

Tvis has been removed