The Lotus Cars Community banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2,524 Posts
Discussion Starter #1 (Edited)
I have built a new motor with BOE's Nikasil block and 9:1 Arias pistons. I'll be hanging a TVS blower on a GReddy manifold; the rest of the system is similar to Phil's original TVS package.
I'll break in the motor with normal induction, then boost with an 90 mm pulley. After I get used to tuning with EFI, I may go to the 85 mm pulley.

Does anyone have 9:1 maps for these boost levels that they can share? I'd greatly appreciate the help. I have the EFI 1.2. If your map is for the X2, I'd still like to get a look at it.

I've looked closely at all the guidance in the EFI Tips thread, but any further advice is welcome, especially concerning tuning DBW. I don't have a DBW control module. I do have a datalogger module, so info about analysis would be helpful.

TIA
 

·
Registered
Joined
·
1,182 Posts
One small note smaller blower pulleys spin the blower faster meaning more airflow/boost/power... So I think you mean to say you will start with a 85mm, then go to something smaller yet.

As for the map you can start with a map from a standard engine. Truthfully engine flow modifications (such as cams, head work, exhaust, etc), will make a larger difference in terms of fueling than compression ratio. So again you can start with the standard engine map and go from there.

The biggest difference you will find with the 9:1 is that the engine will be far more tolerant of ignition lead (timing) than the stock engine at 11.5:1. The flip side of course is that you will likely see a loss of torque/power for the same boost because the engine is 9:1. Truthfully because it is a 9:1 motor you really would find it operates well under higher boost applications (but going to higher boost would open up a can of worms for you).

You may also find with low compression that some of the cam angle tuning may change a little (especially at part throttle)... but for now I wouldn't worry about it.
 

·
Registered
Joined
·
2,524 Posts
Discussion Starter #3
Thanks for your input!

Sleepy when I posted: ). Of course I meant 90 mm, then 85 mm later. I knew I'd be trading away some power with the low-comp pistons, but tuning will be easier. Down the road, maybe I add an intercooled BOE manifold and up the boost a bit…
 

·
Registered
Joined
·
2,524 Posts
Discussion Starter #4
Anyone?

Surely somebody has a map or two I can start with. The clam is off and I start pulling the stock motor Tue. If you know someone who could help, please direct them this,way…
 

·
Registered
Joined
·
2,524 Posts
Discussion Starter #6
Thanks very much, Jim!

BTW, any progress on your hex socket roof trim bolts?
 
1 - 6 of 6 Posts
Top