Overview supercharge/turbocharge solutions

[E.D.]

The options for engine upgrades, either supercharged of turbocharged, for our Elises/Exiges are growing fast! Which is a very good thing, but it also makes keeping an overview of all the various upgrades harder. Therefore I made a table in Excel (first picture below the text-body), based on the excellent list made by JasonD in post #52 in Forcefed Turbo vs. Sector 111 blower??? - Page 2 - LotusTalk - The Lotus Cars Community.
I added some other possible engine upgrades to this list, tried to include prices for as far I could find them and included the internet links where I found the various WHP/ft-lbs numbers.
Based on the useful comments in post #2 from CharlieX (thanks for that, Charlie), I added additional data into the overview for the estimated average ft-lbs during racing on the track (defined as 5500rpm-8000rpm) instead of only using the peak ft-lbs figures. The reason for using the average for the 5500rpm-8000rpm area is that basically the idea is you mostly are in this area on the track.

Using the overview, I made the following graphs (we humans are visual oriented animals, also the reason why we bought our cars) for the Elise (for Exige: see post #8) to make the interpretation of the figures easier:
Graph 1: WHP / ft-lbs (peak)-graph. Creates insight in how much power the upgrades make in both WHP and ft-lbs (peak). The upper right corner is where you want go for maximum power.
Graph 2: WHP / ft-lbs (average race)-graph. Same type of graph as graph 1, only using average race ft-lbs instead of peak-lbs.
Graph 3: Costs per extra WHP / ft-lbs (peak)-graph. Creates insight in how much US$ each additional WHP and ft-lbs will cost you. The lower left corner is where you wanna go for lowest price per additional WHP and ft-lbs.
Graph 4: Costs per extra WHP / ft-lbs (average race)-graph . Same type of graph as graph 3, only using average race ft-lbs instead of peak-lbs.

Please mind:
1. Re Graph 1&3: these are peak figures only, it may/may not say much about the underlying curve. See also post #2 underneath from CharlieX.
2. I made various assumptions, mostly regarding pricing, please see spreadsheet for further details.
3. I'm not a mechanic, so especially with modded upgrades I may have made mistakes in estimating the costs of additional needed things for these mod's. Also I have no idea re streetability and durability.
4. In the graphs 2. and 4. I didn't alter the WHP-figures (yet), because it's my understanding these basically are the result of the torque.

Conclusions:
- The existing SC kits (BWR & S111) don't show any material differences in power output (per $). The Lotus SC Elise by far has the highest price (keeping your warranty comes at a price!).
- Both existing SC kits will have its ass kicked in terms of power output and pricewise, when upcoming SC-kit with intercooler (called NewCo SC w/IC for now) hits the market, this NewCo SC w/IC will have the lowest price per additional WHP and ft-lbs. However, if the Rotrex SC ever enters the Lotus world then, based on Toyota MR2 dyno's, the Rotrex SC will sweep the floor with the NewCo SC w/IC-kit.
- The influence of changing the ft-lbs (peak) figures into ft-lbs (average) figures is almost nil. I.e. all kits lose approx. the same % when peak ft-lbs is adjusted into average race ft-lbs. Exceptions are the:
FF275 kit: has a lot of torque already in the lower RPMs but loses ft-lbs when ft-lbs peak is adjusted into ft-lbs average race.
NewCo SC w/IC: which almost doesn't lose any power when ft-lbs peak is adjusted into ft-lbs average race.


I hope you guys find it handy in weighing your upgrade options! If you have any questions or suggestions to add other upgrades (including ref's), don't hesitate to post! You can find the file of the spreadsheet in post #9 for further abuse.

Thanks Enrico

[charliex]

Nicely done, but just be wary of peak HP numbers, i just did a tune that adds 10ft lbs of tq and around the same in HP across most of the powerband, but the peak hp is almost identical -/+1 HP difference

i usually sample at 500RPM and do a graph from that instead.

[jasond]

Yea, I thought of doing something similar (like in the spirit of the weight saved / dollar thread), but realized how misleading a number like peak WHP could be... there's just so much more to an engine upgrade like a supercharger or turbo than a single number can represent. Still, interesting data to look at, I really expected the '08 SC to have the lowest $/WHP number.

[Matt in Houston]

Originally Posted by charliex

Nicely done, but just be wary of peak HP numbers, i just did a tune that adds 10ft lbs of tq and around the same in HP across most of the powerband, but the peak hp is almost identical -/+1 HP difference

i usually sample at 500RPM and do a graph from that instead.

Any hints what tune that might be on?

I'm sending you my ECU on Monday overnight FEDEX...Looking forward to driving your 06 Katana tune!!! It's going in tomorrow...


Thanks for the chart...the links are a nice touch!

[Emapeels older sis]

Thank you very much. This is exactly what i have been looking for EXACTLY, I kinda wanna go witht he KAT sc mod 1, thats more then enough power.

[Emapeels older sis]

Can you explain what the Katana mod 1 is exactly? is it something they offer or what?

thanks

[E.D.]

Originally Posted by Emapeels older sis

Can you explain what the Katana mod 1 is exactly? is it something they offer or what?

thanks

It's a mod made by other ET-members. See the reference column in the attached spreadsheet in post #1 for the ET-post in which this mod is discussed in more detail by its makers. I'm a technical nitwit, so I don't know if it is a straightforward mod.

Enrico

[E.D.]

In this post you'll find basically the same info, but this time for the Exige instead of the Elise.

[E.D.]

The spreadsheet.

[Bavarian Motorist]

I don't think an Exige S 240 will have 230 WHP...


What is your source?

[charliex]

If use Alt+PrtSc with the application it should capture only the window you're got activated.

[E.D.]

Originally Posted by charliex

If use Alt+PrtSc with the application it should capture only the window you're got activated.

Thanks for the tip! I didn't know that.

[E.D.]

Originally Posted by Bavarian Motorist

I don't think an Exige S 240 will have 230 WHP...


What is your source?

No source, as stated in the column 'remarks and references' it is just an estimation: 240HP/220HP * the average dyno'd WHP for the Exige S. When you open up the spreadsheet in post #9 you can see the formula.

[Bavarian Motorist]

All right, fair enough.

[E.D.]

Whoooooo.
I made a post which has r'ved the holy status of a sticky. !!!
To celebrate, I'm gonna get sooooo drunk tonight!

[exarkun1178]

congrats! ill be out drinking tonight as well, ill cheers to you when i do.

[E.D.]

Updated Elise overview spreadsheet/graphs with Bemani figures.
Now waiting for first stage II BWR / S111 dyno's....

[Casey@ForcedFed]

You forgot FF275 w/gt28rs upgrade...270whp 195tq...I'll get a dyno sheet up sometime.

[E.D.]

Originally Posted by Casey@ForcedFed

You forgot FF275 w/gt28rs upgrade...270whp 195tq...I'll get a dyno sheet up sometime.

I would gladly add that one...

[slaughtr]

Also, I would add that at no extra cost (other than dyno time), a FF 275 kit with a standalone ECU can be configured to have a second map with race gas producing much better numbers. On 100 octane gas, my car produces 252 whp and 221 ft/lbs of torque. I only plan to use this map on autocross days (100 octane is $8/ gallon) but I wanted to point out that option.