998 T2 Turbo Build
Turbo Mini Forums

Holds onto the power well!

Yeah I'm thinking something is slightly odd with my build though. I've been looking over the results that wil_h and Paul S have achieved.

By 4000 revs they have almost 100 lbft of torque (as I used to have) but with mine I have about 60 lbft.

Anyone suggest a reason for this? would cam timing cause a dramatic loss like that?

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

here's a plot of my afr (solid line). Any feedback welcome

Edited by dan187 on 31st Mar, 2011.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

I think that it may be a combination of being too rich at the bottom end and doing the run in 3rd gear.

My 998 on 12 psi on a T2 will only get full boost at 4k in top gear. At the Smart rolling road day, the third run was in 3rd and boost did not come on till 5k. It did do 138hp though :)

Did they measure boost during the run? Does the rpm reading look about right ? i.e. did you actually see 7.5k on the tacho.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

his pressure sensor wasn't working unfortunately. yeah rpm seemed about right.

probably 3rd gear like you say. found one of your graphs. red was 3rd gear compared to blues in 4th

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

This is a later "corrected" curve.



Hp is at the wheels on the above, are yours?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

nice one.

no, mine is corrected for flywheel.
Should have asked for a 4th gear run and wheel power but was more concerned with getting the timing right.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Looks absolutely quality

Iv got a 1098 which I want to turbo. however how do I go about it and what do I need to do it?

there is a sticky in the 998 section

Rusty by nature

A new addition: recirculating dump valve

It feels like a massive improvement in shift performance. Before, the turbo would surge on change and take a bit of time to spin up and be useful again. Now its maintains the boost very well. Get a lovely subtle pffft noise too. Much better than having all those turkeys under the bonnet gobbling away.

Edited by dan187 on 31st May, 2011.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo