I don’t believe there are easy gains above 320. The OEM standard bottom end is starting to look shakey and the smaller pulley sizes are producing a lot of heat from the s/c, so it’s nowhere near a linear curve, power gain to s/c rpm.
The way around it is new bottom end and more efficient TVS s/c.(or Audi/Honda). All options involve big cost.
If it’s a track car, strip it down??. The power to weight with 320 would be a match for many.
[quote=661]I don’t believe there are easy gains above 320. The OEM standard bottom end is starting to look shakey and the smaller pulley sizes are producing a lot of heat from the s/c, so it’s nowhere near a linear curve, power gain to s/c rpm.
The way around it is new bottom end and more efficient TVS s/c.(or Audi/Honda). All options involve big cost.
If it’s a track car, strip it down??. The power to weight with 320 would be a match for many. [/quote]
Agreed - But I need to know the most efficient way to achieve 320. My understanding is that from my position (Komotec 280), adding a 2bular header, smaller pulley and a re-map should do the trick. Probably makes sense to change the ECU while i’m at it. And losing all un-necessary weight.
Questions are: which ECU? Which size pulley?
As to internals, if i decide to build the engine which make would you go for?
Would appreciate any advice I can get at this stage.
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I haven’t gone down the internals route as I’m at 276hubs (c.317 fly) . If I ever go for more power then I’d change the bottom end and look into it then.(The cost is prohibitive presently and driver training is more important to me)
I’ve got a 2.8" pulley from RLS, Tullett exhaust system(2Tubular would do the job obviously) and ECU from SSC. I would look at where you are going to get the car tuned before making your mind up on the ECU.Ask them if they are familiar with any one ECU above another (SSC-Adaptonics, JSR- Syvecs, EP- Gems). A reputable tuner should be able to deal with any of them but the software is sometimes easier/more familiar from one to another.
As mentioned previously, dropping pulley sizes below 2.8 is not going to gain you the expected 10hp per 0.1" drop that you get at bigger sizes ( all other things not being a factor like restrictive exhaust etc) with the OEM S/C. It just gives you smaller gains and more heat.
The issue in getting more than 320 at the flywheel is largely down to the supercharger, the smaller you go with the pulley, the more inefficient the process and the more energy lost through heat etc.
We’ve put an HKS charger onto the 2ZZ and taken it to 350 but this also needed cams, 700cc fuel injectors and 4 bar of fuel pressure so we had to change a few other things. Although this was done on an engine with a stock bottom end I wouldn’t recommend it.
It’s now running in an Exige quite happily but with updated rods, pistons, bearings and a higher spec head. It’s running 270bhp with an 80bhp PTP option. Total cost of the charger, ECU, plumbing is about �4k. Charge cooling not as essential with this charger but still recommended.
272 @hubs here with STANDARD lotus 260 ecu …
…so is 4 bhp all that can be found using this SSC ecu ?
…on a 2.8 pulley this is …
[quote=jfk]272 @hubs here with STANDARD lotus 260 ecu …
…so is 4 bhp all that can be found using this SSC ecu ?
…on a 2.8 pulley this is … [/quote]
If you are running a STANDARD ECU with a 2.8 pulley without a reflash then it’s not your gearbox you need to worry about.
Hee hee …
I might have ‘tinkered’ with the fueling a tad to suit the pulley size !
…love the smell of hydrocarbons …
