RV8 3.9 Improvements

[Belle427]

I'm doing a mild refresh on a 1995 Tvr Chimaera, which has the 3.9 interim/intermediate engine, so no cross bolting.
Are there any small improvements that can be made to the block area without going crazy?
I was thinking of maybe adding a lightened flywheel and Arp fasteners, just small worthwhile improvements.
I don't really want to think about top hatting it as then a reconditioned short motor starts to make more sense.
Thanks for any advice.

[Steve_D]

The RV8 is torque biased motor so unless you plan to do cam and induction mods to make it rev more then I doubt the ARP fixings will be required (even though they are nice) and the lightened flywheel may make the engine more susceptible to the well know 'Shunting' issues.

Steve

[anonymous-user]

I'd say in all cases, the best thing you could spend your money on would be a modern engine controller!

Leave the h/w alone, and fit a decent modern engine controller, spend a proper amount of time mapping it, and get more power, lower consumption and a much nicer drive........


(assuming the car is still on the original 14CUX controller for the 3.9)

[Belle427]

I have just purchased some stage 3 heads, Mc1 camshaft, modified inlet manifold, trumpet base and plenum, all from V8D.
Its still on the existing 14cux which works well currently with no shunting, I am interested in going aftermarket but not being local to any mappers is putting me off, even though I could diy the install.
Its also not very clear which is the better system but the Megasquirt setup looks very good value for money.

[GreenV8S]

Belle427 said:

I have just purchased
Its still on the existing 14cux
not being local to any mappers is putting me off

That new hardware will mean the 14CUX needs to be remapped in any case. Very few people has the skills and equipment necessary to do that for themselves, so sticking with the existing ECU means you need to find somebody to map it for you. Since there are relatively people in a position to do that, they can afford to charge a premium.

The advantage of the aftermarket ECUs is that more people have access to map them. Most of them can be mapped DIY if you are willing to put in a lot of time and effort. If you want to have it mapped professionally then the cost of doing that becomes significant relative to the cost of the hardware, and you should be including the choice of who will map it, and cost of that, and the list of ECU brands they're willing to work with, in your purchasing decision. A cheap ECU that takes ten times as long to map could work out more expensive in the end.

[Belle427]

I’m guessing most aftermarket systems will come with a base map to get you going?

[GreenV8S]

I've only installed and mapped Omex and Megasquirt myself. Each took me about half a day to get them to start and idle, and about twenty hours of logging and tweaking to get a decent driveable map. To be fair, this was with a pretty unusual intake setup and for a more conventional setup that may have gone quicker. I was a novice in both cases. I'd expect an experienced mapper using a rolling road to finish the whole thing in a few hours and do a better job. But what's the fun in that?

[Arnold Cunningham]

My 3.9 has been on megasquirt for the last few years. I left the dizzy in and the MS triggers off it.
Runs well and easy enough to do.

[Boosted LS1]

Go for an emerald and loom. I'm sure it can be supplied with a pre-loaded map to get you going. I can help if you need any advice.

[anonymous-user]

Any engine controller with proper 3d mapped and compensated ignition timing is going to make a world of difference compared to the 14CUX dissy based system

[Arnold Cunningham]

Yeah, ditching the dizzy is something I should do on RV8. The other motor I have MS on has a 60-2 wheel and from the first moment I set it up the timing it's 100% rock steady. Timing light no longer required.

Max_Torque said:

Any engine controller with proper 3d mapped and compensated ignition timing is going to make a world of difference compared to the 14CUX dissy based system

[Belle427]

Arnold Cunningham said:

My 3.9 has been on megasquirt for the last few years. I left the dizzy in and the MS triggers off it.
Runs well and easy enough to do.

I do like the look of the kits from Extra Efi, very comprehensive and good support too.

[Arnold Cunningham]

I built mine a few years back now - it was a bare bones kit from DIY Autotune.

[jjohnson23]

If you have time try reading this,there are some very knowledgeable people about.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Arnold Cunningham]

Looks a bit complicated, TBH.

[anonymous-user]

The problem is modifying the std ecu means you're stuck with crappy ignition angle "control" (and i use the word control loosely!)

Far better to ditch the CUX, fit some coil packs, a suitable crank trigger, keep the dizzy for TBC so you can go sequential fuelling too

[Belle427]

jjohnson23 said:

If you have time try reading this,there are some very knowledgeable people about.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Yes id agree, I have one of steves chips fitted and it makes the car run very well. Hats off to all the hard work carried out by these guys.
My attitude is usually if it aint broke then why fix it, if I were to go forced induction in the future it would make more sense to go aftermarket.

[Arnold Cunningham]

Generally I agree - but if you've fitted a chip, then it was broke and you fixed it, right?
IMVHO my motor runs night and day better since I've removed the CUX and gone megasquirt. I should however go wasted spark & crank trigger. Does anyone make a distributor "plug" like this for the RV8 - https://www.summitracing.com/int/parts/maa-29007/o... ?

Belle427 said:

My attitude is usually if it aint broke then why fix it

[Boosted LS1]

You could use the dizzy as a plug or have I missed something?

[Arnold Cunningham]

Yeah - it looks half finished with a full distributor still sitting there.