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Does anyone know whether all of the 2GR engined cars have identical camshaft profiles?

In particular, did Lotus retain the original NA Evora camshafts when they added the supercharger to the Evora S? I also wonder whether the later 400/410/430 cars have the same camshaft profiles as the Evora S / Exige S / 350 / 380?

The reason I am asking the question is because I am currently looking into camshaft profiles for the next stage of my build.  Supercharger-specific cam profiles are very different to profiles that are optimised for NA engines - they have more exhaust lift and duration, as well as a wider lobe separation angle to ensure the lowest possible overlap.  Normally when building hot cams for an NA engine you would go for more intake lift/duration and more overlap, which is what the CatCams profiles have for example, so they are clearly designed for an NA build and not a supercharged engine.

As far as I can can tell from DeRoure, the parts numbers for the cams on all of the cars are the same, so I would assume that they all have identical cam profiles.  I find it a bit odd that Lotus didn't change the cam profile when going from NA to supercharged in the first place, and that even the latest 430 cars are still running the same cam profiles as originally designed for an NA engine with far less power!  Makes me think that there is a lot left on the table that can be gained by optimising the cam profile for a supercharged engine - especially for those running the TVS1900 unit such as myself.

I'd be curious to hear what cam profiles people are running when they have swapped the cams.  Presumably this is the issue that they have sought to address.

Thanks!

 

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Correct me if I’m wrong but I don’t think Lotus touch the engine internals after they empty the crate from Toyota. 

Give ES motorsport a shout as they race Evoras and am sure they will know if cams differ between models, but I don’t think they do as per above post. It is something I am looking at for my NA with som

This.  (Which is also why all of the OEM Lotus cars have the (generally derided) cats in the headers). 

Posted Images

Give ES motorsport a shout as they race Evoras and am sure they will know if cams differ between models, but I don’t think they do as per above post. It is something I am looking at for my NA with some manifolds.

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2 hours ago, LotusLeftLotusRight said:

Lotus don’t touch the engine internals after they empty the crate from Toyota. 

This. 

(Which is also why all of the OEM Lotus cars have the (generally derided) cats in the headers). 

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4 hours ago, Whitey said:

Give ES motorsport a shout as they race Evoras and am sure they will know if cams differ between models, but I don’t think they do as per above post. It is something I am looking at for my NA with some manifolds.

Thanks, I am speaking to the usual suspects (including ES) about my build but also doing my own independent research.

If you are looking for upgraded NA cams, take a look at the CatCams profiles. They may be of interest to you.

Sounds very much like decent gains from proper supercharger-specific cams should be low-hanging fruit in that case. I suspected that might be the case but thank you for confirming!

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I am quite sure I read in another thread, here or on LotusTalk, that the exhaust cam differs from Toyota original. But, if I read on the MWR site, they state the same OEM lift/duration for the Toyota vehicle's 2GR-FE as they do for Lotus.  Other than that I agree about what you say. I find it remarkable that also after market tuning cam's for the supercharged engines keep the same specifications for intake and exhaust. Especially as I understand there are more to gain in porting the exhaust than the intake port.

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Everything I have read and heard suggests that the cams are Toyota standard cams, and therefore obviously not designed for a supercharged engine. The most concrete evidence is that the part numbers for the NA cams and the 430 Cup cams are the same. This is good news for me because it means there is lots of room for improvement!

I intend to port and polish both intake and exhaust side. The most gains will be on the exhaust side for sure, especially if combined with cams that have longer exhaust duration in particular.

This is interesting viewing on the topic:

 

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Will be interested in following your investigation as have thought that there is more to be gained from cams designed to suit the supercharged application. However this would require a free flowing exhaust  and the ability to change the VVT and ignition timing. Less overlap and I think an increase in exhaust valve size combined with faster ramp angles may be preferable to increasing lift to increase flow/duration.

As supercharged applications of the 2GR-FE increase, I would think that someone like CAT cams would design sc cams if there was enough interest.

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There is not much space in the cylinder heads for larger valves, and then you would have to get custom made valves / seats etc to fit, which becomes difficult/expensive.  The valves are actually pretty big already anyway.  They are the same size as those on the 2UR that is used in the Lexus ISF, which has titanium intake valves, so those are probably what I am going to use (with inconel exhaust valves due to the extra heat).

There are are however definitely gains to be had in porting the valve seat area and short turn radius of the exhaust valve (and, to a lesser extent, the intake side).  Obviously this needs to be combined with a free-flowing exhaust, but I already have a full 2bular system, which removes the primary cats and is 70mm all the way through after the headers.

Correct cams will be critical to making the most of the supercharged intake side and the free-flowing exhaust side.  As you say, need less overlap and optimised timing so as to avoid losing supercharger boost.  I think more exhaust duration will be helpful too (particularly to ensure that exhaust duration is longer than intake duration), although lift is probably less important.

I am speaking with Kelford Cams at the moment.  They having something in the pipeline that might fit the bill.

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Oh just spotted this thread! Please keep it updated with any news, I’m very interested.  Thanks for the info already posted will have a look soon. 
 

Ive been speaking to ES for while now about cams for the NA engine. Last time we spoke they were not ready yet. I think Dave said they produced more torque but same peak power? 
 

They have a set of cams for the supercharged engine that are fully developed. Just the NA engine needs work. I guess most people prefer to swap for a supercharged car and then upgrade further. 
 

I’ll give Dave a nudge and see what’s happening with the NA cams. They are usually too busy with the race cars but hopefully with the shorter season this year they have some more resources to work on the cams 🤞🏾

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There are lots of options already for the NA motor because most people tuning the engine (ie the MR2 swap crowd) don’t have superchargers. Have a look at MWR or CatCams for example. They offer your typical hot cam profiles ie more lift/duration especially on the intake side and a bit more overlap. That’s what you want for a NA motor, but it’s almost the polar opposite to what we need for a supercharged application, and that’s what is harder to find.

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I thought this a good explanation for those interested in the subject of different cams for supercharged engines - from kcams NZ

'Supercharged engines typically have a shorter intake, longer exhaust, and wider lobe center angle (LCA).
Supercharged engines can continue pushing charge into the cylinder longer than an NA engine, and also the greater pressure differential between the manifold and the cylinder means the cylinder is filled quicker. This means they like a shorter intake duration on a later centreline, compared to their NA counterparts.
Higher cylinder pressure after combustion means more gas to get rid of, so the exhaust valve is opened earlier than on an NA engine. This means longer exhaust duration, on an earlier centreline.
Early exhaust centreline and late intake centreline means a wider lobe centre angle. This means there is less overlap which also helps stop the pressurized intake charge being lost out the exhaust valve.'

 

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I got a response from Kelford overnight (they are based in NZ).  This is their current planned cam options, with scope for customisation if needed.  Their Stage 1 (263A) cams look like what I need.  I find it hilarious that their "Stage 1" is "only" 500-700hp - means I must have come to the right place!!  It also show what huge potential there is in this engine.

Camshaft Part Number

Application

Advertised Duration

Duration @ 1mm Valve Lift

Valve Lift

Suggested Centrelines

Lift @ TDC

Spring Requirement

 

 
   

In

Ex

In

Ex

In

Ex

In

Ex

In

Ex

   

Stock OEM

Standard profiles for comparison.

254

254

202

202

11.0mm

10.75mm

Vari

Vari

Vari

Vari

OEM

   

263-EZP

Easy power drop in cams, designed to work with stock valve springs on near stock engines. Great power-up to suit stock engines with bolt on's.

258

258

218

218

11.0mm

10.75mm

Vari

Vari

Vari

Vari

OEM

   

263-A

Stage1 performance cams, suited to 500-700hp, 8000rpm and 30psi when matched with our spring kit.

264

270

226

230

11.5mm

11.0mm

Vari

Vari

Vari

Vari

KVS263

   

263-B

Stage two Street/Strip cams, Suited to 700-1000hp, Great with twin 62mm turbos and E85.

272

276

234

238

12.0mm

11.5mm

Vari

Vari

Vari

Vari

KVS263

   

263-C

Drag cams, Great for 4.0ltr stroker builds and alcohol blended fuels. Suits professionally built engines. Suits fixed timing or can be run as variable, great care needed checking Piston to Valve. Rated 1200-1600hp.

278

284

240

244

12.5mm

12.0mm

110

118

Vari

Vari

KVS263

   

I don't have any details on overlap yet but have asked Kelford to confirm what overlap their Stage 1 cams use. I expect it will be a fairly wide lobe separation angle/low overlap design give the exhaust duration, which would be perfect for what I want.  Kelford also said that they would branch into an NA specific line if the interest was there.

By way of comparison, the MonkeyWrench Racing reground cam profiles are as follows: 

MWR Stage 1: Duration 256I/256E, Lift 11.45mmI/11.45mmE

MWR Stage 2: Duration 266I/266E, Lift 11.67mmI/11.67mmE

MWR Stage 3: Duration 272I/272E, Lift 11.70mmI/11.70mmE

These all look fine but are very much "OEM plus" rather than being re-designed for a supercharger application, which is what I want, particularly since I have such a big supercharger that is capable of providing a lot of boost if needed.

I also attach the CatCams selection of cams, which are NA-specific (and very aggressive in their "hot street/dirt track" profile!). The link is here for full details: http://www.catcams.com/engines/camshaft-setup.aspx#

image.png

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Overlap is the number of degrees where both inlet and exhaust valves are open at the same time. For Overlap degrees add the opening number of the inlet cam to the closing number of the exhaust cam.

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No, you will need to get the degrees of the opening/closing events at the valve from Kelford spec card.

Do you have the specs for the standard cams showing opening and closing events? Would be in tech data in manual?

 

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Have you spoken to Swindon powertrain re their billet spec cams they manufacture?

Apparently their camshafts are for race engines, so unfortunately my bad.

Edited by DarrylV8

Darryl & Sue

Proud to drive and own a true British supercar the Evora GT430

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6 hours ago, DarrylV8 said:

Have you spoken to Swindon powertrain re their billet spec cams they manufacture?

Apparently their camshafts are for race engines, so unfortunately my bad.

Yes, I’ve spoken to them. Their cams are mainly aimed at 4.0l stroked NA race cars although they can custom make any cams. But they are also seriously expensive. At the moment I think Kelford is going to be the best option.

13 hours ago, IanA said:

No, you will need to get the degrees of the opening/closing events at the valve from Kelford spec card.

Do you have the specs for the standard cams showing opening and closing events? Would be in tech data in manual?

 

I do not I’m afraid 

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Hi Matthew,

We have also been talking to Piper they will manufacture camshafts     to your own specification, thought their cost was reasonable, but obviously not sure how they compare to Kelford.

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Darryl & Sue

Proud to drive and own a true British supercar the Evora GT430

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I spoke with Piper but they said they did not make cams for the 2GR and it would need to be custom, as you say. I wanted to find someone who had already done the development work and had some good cam profiles already prepared, rather than me having to effectively guess what profiles would work well.

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Interesting with the Kelford offering, but they are obviously referring to turbocharged installations. Have any of those cam profiles been used in any SC engine builds? They look like decent upgrades, but again, you work differently with cams for TC's vs. SC's.

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  • 1 month later...

Worth keeping this thread alive in the pursuit of SC cams for the 2GR-FE.

Most off-the-shelf Forced Induction profiles that I have seen for this engine have been designed for turbocharging which requires different valve control to a supercharger.

The turbo delivers ever increasing boost while the Supercharge has a window of controlled boost.

I think the use of turbo cams on an SC car would result in power band up high but sacrifice mid range torque.

Am not an expert, but like the OP would like to see someone develop and test SC cams for this engine as I think a lot could be gained rather than just putting bigger blowers on.

By now there should be a good market for those with 1320 and 1740 blowers on the Exige and Evora that are looking for a bit more performance, at a reasonable cost.

The Kelford cams seem to be for Turbo application, but hard to judge as they don't publish event angles.

Toyota only designed the 2GR-FE for naturally aspirated use, so there seems to be an opportunity for cams designed for the increased Supercharged application of this engine.

For reference, this second-hand info may be the oem n/a valve events, showing VVT range, for the 2GR-FE but am sure Toyota publish full info somewhere.

2GR_FE.JPG

Edited by IanA
more info
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