Project Build - What Engine?

Project Build - What Engine?

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shirt

Original Poster:

23,471 posts

208 months

Sunday 27th May 2018
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I have been trawling the internet all evening, in the process making a sizeable dent in a bottle of Bruichladdie, looking mainly at race car classifieds and tuner sites, leading me to start this discussion:

I recently purchased a Radical SR8 LM rolling chassis - complete less drivetrain. On the way to me is a Hewland FTR sequential transaxle which has a max torque limit of 240 lbs ft. If this was your project, what engine would you be putting ahead of it? Assume you will be dry sumping and modifying as you wish, but the kicker is that torque figure.

Current favourite is a Renesis [RX8] motor which is for sale in the states with dry sump kit and a host of other bits. A 13b N/A peripheral ported lump would be preferable but the former is much cheaper [around $5k]. The Renesis is also used with the same transaxle in the Star Mazda single seater series so there is a proven route, spares, support etc. One big draw is that the lightweight engine and rev happy character will suit the original intention of the Radical cars.

I have debated many engines. K20, Duratec, 1.6 ecoboost [was a strong contender, but I fear too much torque], jag v6 and everything else in between.

Just wondering if I am missing something obvious or if there is anything better than the Renesis. Be it power, packaging, ease of installation or otherwise, what would you do and why?

NB: The roller cost me £3k and the Hewland just over that, so keep fantasy budget specs to one side! Intended use is trackdays, sprints and 1hr endurance races.

Cheers!

Edited by shirt on Sunday 27th May 22:51

samnorthy

288 posts

214 months

Tuesday 29th May 2018
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Shirt,

All of the bellow are running the FTR box, not sure what if anything they do to manage the extra torque.

https://racecarsdirect.com/Advert/Details/92872/20...
https://racecarsdirect.com/Advert/Details/91060/ad...
https://racecarsdirect.com/Advert/Details/92743/pa...

The Jag V6 would be my option, easy tune-able to 280/300bhp, cheap to source. Jenvey make a nice set of ITBs

Just add this and your away!

https://racecarsdirect.com/Advert/Details/92928/pa...

https://store.jenvey.co.uk/throttle-body-kits/jagu...


parsonsj

49 posts

97 months

Saturday 2nd June 2018
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Preliminary measurements tell me that a V6 is the best option (shorter in length than an I4). Have you looked at the Subaru EJx or EZx engines? They sound like a Porsche, you can find parts anywhere, and they have lots of aftermarket support for dry sump, clutch, cams, and related goodies.

shirt

Original Poster:

23,471 posts

208 months

Sunday 3rd June 2018
quotequote all
The original idea was to use an EJ20 as its been done in the states with an SR3. In fact it was that build thread which lead to me agreeing to buy the roller in the first place. I then just fancied the rotary based on high rpm ability and ease of packaging, but now thoughts along the lines of a proven route come creeping back.

The jag has risen in prominence in my thoughts very quickly Sam. Should be able to source a donor locally and parts are cheap. It's going to be that or rotary but I think the v6 edges it at this stage. I just need to do some comparisons of cost on excel and see which comes out on top. Wouldn't mind some pub chat comparing the two when you're onshore.

Purpose of this thread was to see what other options there were given the fact that PH is such a diverse and knowledgeable platform. However as the mods seem to have buried it in a subforum few venture into then there's naff all chance of that now.

samnorthy

288 posts

214 months

Monday 4th June 2018
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Shirt,

No problem re the pub talk, will let you know next time I'm about,

Maybe put up a post in the Engine & drive train section? make it non radical related ie need a mid-engine solution for light weight race car....


andygtt

8,345 posts

271 months

Tuesday 10th July 2018
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AJ30 jag engine would be ideal, ITB's and a dry sump and you can see 300bhp and 8400rpm.... cams available off the shelf to go really made if you want to rev past 9000rpm.

Be aware the oil pump is a limitation at above 8000rpm, hence you need the dry sump to go above that reliably.

Im swopping my Duratec internals into one of these for my track car... slightly more torque tho as its turbocharged.