New build decision to make

dbv8 · Post by **dbv8** » Mon Oct 12, 2015 10:49 am

So I am getting the engine rebuilt at ACR and Roland will be fitting his Wildcat heads to the offset ground 5.0 bottom end with chevy rods and forged pistons.

If I stay NA then the done thing is to fit throttle bodies that will cost me north of 2k even with discount.
I do like the idea of having 400 bhp NA and having a failsafe direct port nitrous system.

Or….
Keep a fairly standard inlet and go turbo. I don’t think its unreasonable to think it would be over 500 bhp on fairly modest boost.

But we need to consider the fact that if I do as planned I will be covering a few thousand miles on the road next year so it has to be reliable and driveable.

Blown v8 · Post by **Blown v8** » Mon Oct 12, 2015 3:30 pm

Go turbo,still can be reliable and economical

r2d2hp · Post by **r2d2hp** » Mon Oct 12, 2015 4:40 pm

While throttle bodies look and sound good they can be a PITA to keep in sync.

DaveEFI · Post by **DaveEFI** » Mon Oct 12, 2015 5:01 pm

r2d2hp wrote:While throttle bodies look and sound good they can be a PITA to keep in sync.

I'd be interested to know how much difference they make on a relatively low revving engine?

SuperV8 · Post by **SuperV8** » Tue Oct 13, 2015 7:27 am

I'd be interested to know how much difference they make on a relatively low revving engine?

I thought the main reason behind using throttle bodies is they help tame big cams compared to a plenum type inlet? so you can use bigger cam without loosing as much low rpm?

One vote for turbo from me!

Tom.

DEVONMAN · Post by **DEVONMAN** » Tue Oct 13, 2015 7:55 am

My vote is for Turbo.

I've been running turbos on an RV8 since 1994 and nothing compares in my opinion. The down side is all the extra plumbing which ain't so easy to get pretty,

Denis

DaveEFI · Post by **DaveEFI** » Tue Oct 13, 2015 8:09 am

SuperV8 wrote:
I'd be interested to know how much difference they make on a relatively low revving engine?
I thought the main reason behind using throttle bodies is they help tame big cams compared to a plenum type inlet? so you can use bigger cam without loosing as much low rpm?

One vote for turbo from me!

Tom.

Ah. Thanks for that.

chodjinn · Post by **chodjinn** » Tue Oct 13, 2015 9:38 am

Turbo, always turbo. For the price of the throttle bodies alone you could get a decent turbo system sorted out. Holset turbos are pretty damn good and cheap compared to garrett etc. I recently got a HX50 for my 4litre V8 for £350 delivered brand new, from Compressor Racing. Spend money on a decent wastegate like Tial. Don't really need to run a blow off valve either TBH. Intercoolers are relatively cheap these days. You could do the hardware for a grand easy, plus pipework.

stevieturbo · Post by **stevieturbo** » Tue Oct 13, 2015 5:26 pm

Definitely turbo, and the TVR exhausts up front just beg for a turbo or two

dbv8 · Post by **dbv8** » Tue Oct 13, 2015 9:49 pm

stevieturbo wrote:Definitely turbo, and the TVR exhausts up front just beg for a turbo or two

The decision has been made. Will be a single turbo that might get me to 2nd place in RWD at TOTB next year

stevieturbo · Post by **stevieturbo** » Tue Oct 13, 2015 10:03 pm

dbv8 wrote:
stevieturbo wrote:Definitely turbo, and the TVR exhausts up front just beg for a turbo or two
The decision has been made. Will be a single turbo that might get me to 2nd place in RWD at TOTB next year

The rwd class is usually very tight although myself and Duncan have a habit of meeting each other in the finals.
Rain put a stop to it this year, but the 1/4 times on the day were only 0.04 apart !

I just cant get mine to grip to go much faster over the 1/4. You did really well with yours until the problems, so it definitely has potential to be well up there

dbv8 · Post by **dbv8** » Wed Oct 14, 2015 8:58 pm

stevieturbo wrote:
dbv8 wrote:
stevieturbo wrote:Definitely turbo, and the TVR exhausts up front just beg for a turbo or two
The decision has been made. Will be a single turbo that might get me to 2nd place in RWD at TOTB next year
The rwd class is usually very tight although myself and Duncan have a habit of meeting each other in the finals.
Rain put a stop to it this year, but the 1/4 times on the day were only 0.04 apart !

I just cant get mine to grip to go much faster over the 1/4. You did really well with yours until the problems, so it definitely has potential to be well up there

Was a joke about 2nd place but I do think I can run some good numbers. It was my first time at TOTB and I thought despite being very different to the usual RWYB and race meets at York, it was a great event and I will be trying to get a showing of modified TVRs along next time. We need more Brit stuff in the pits.

stevieturbo · Post by **stevieturbo** » Wed Oct 14, 2015 9:06 pm

Over many years, there have only been a handful of cars running 10's, and they're usually high 10's. Myself included.

I've seen years where I couldnt even get into the 10's there, traction can vary a lot.

One of the quickest rwd cars to run was an MR2 a few years ago which did a very low 10. But usually when any quick MR2's are there, they always blow up.
They have everything they need to put in great times, except reliability.

IMO that's the only type of car that could potentially walk the rwd road/drag class, a light mid engined car with a lot of power.

Other than that and it'll always be tight

I'm sure there are drag cars with huge tyres that could run quick times too, but such cars have never been allowed in the normal road legal classes ( even though many cars there are nowhere near road legal )

dbv8 · Post by **dbv8** » Thu Oct 15, 2015 11:51 am

I think I could have nudged a 10 if my engine hadn't detonated.
The new motor is getting a turbo as we speak. The engine is getting built with wildcat heads and a custom inlet. Yet to decide on the turbo and cam.

Would be interested to hear suggestions here. Currently considering a copy GT3582 from the states to save on the mounting costs. I have a Crower 50304 mech and real steel hydraulic Tornado and Typhoon cams all in excellent condition with followers stored in order to choose from.
CR will be determined when the chambers in the wild cat heads are CNC machined. Current thoughts are 8.75:1

stevieturbo · Post by **stevieturbo** » Thu Oct 15, 2015 12:59 pm

dbv8 wrote:I think I could have nudged a 10 if my engine hadn't detonated.
The new motor is getting a turbo as we speak. The engine is getting built with wildcat heads and a custom inlet. Yet to decide on the turbo and cam.

Would be interested to hear suggestions here. Currently considering a copy GT3582 from the states to save on the mounting costs. I have a Crower 50304 mech and real steel hydraulic Tornado and Typhoon cams all in excellent condition with followers stored in order to choose from.
CR will be determined when the chambers in the wild cat heads are CNC machined. Current thoughts are 8.75:1

If you are going with boost, dont go nuts spending a fortune on intakes etc Likewise with camshaft, mild is the order of the day. Big cams just do not work well, so between those two, definitely the Typhoon, and maybe even throw in some Rhoads lifters.

Certainly a chinese turbo would be good to start with for fitting up etc, however I'd probably want a T4 flanged unit myself. T3 is a pretty small flange for a single on a 5.0 engine.

I've a Garrett GT4094R sitting here if it's any use, was on a friends Subaru but at the time it proved a little too laggy so swapped it for a different unit. Although even that came down to poor camshaft choice as it didnt chance much even with the new turbo. Dropping to a slightly lesser spec cam seen almost 1000rpm improvement in spool, and no difference at all in power.
But he changed turbo first and then camshafts to discover that !

We are hoping to get to Santa Pod or Shakespeare on the weekend of 24/25 Oct and could bring it over if interested ?